diff --git a/src/AddressBook/AddressBookProtos.cs b/src/AddressBook/AddressBookProtos.cs
index cace043..2ed0a11 100644
--- a/src/AddressBook/AddressBookProtos.cs
+++ b/src/AddressBook/AddressBookProtos.cs
@@ -304,22 +304,22 @@
                   if (unknownFields == null) {
                     unknownFields = pb::UnknownFieldSet.CreateBuilder(this.UnknownFields);
                   }
-                  ParseUnknownField(input, unknownFields, extensionRegistry, tag);
+                  ParseUnknownField(input, unknownFields, extensionRegistry, tag, field_name);
                   break;
                 }
                 case 10: {
-                  Number = input.ReadString();
+                  result.hasNumber |= input.ReadString(ref result.number_);
                   break;
                 }
                 case 16: {
-                  int rawValue = input.ReadEnum();
-                  if (!global::System.Enum.IsDefined(typeof(global::Google.ProtocolBuffers.Examples.AddressBook.Person.Types.PhoneType), rawValue)) {
+                  object unknown;
+                  if(input.ReadEnum(ref result.type_, out unknown)) {
+                    result.hasType = true;
+                  } else if(unknown is int) {
                     if (unknownFields == null) {
                       unknownFields = pb::UnknownFieldSet.CreateBuilder(this.UnknownFields);
                     }
-                    unknownFields.MergeVarintField(2, (ulong) rawValue);
-                  } else {
-                    Type = (global::Google.ProtocolBuffers.Examples.AddressBook.Person.Types.PhoneType) rawValue;
+                    unknownFields.MergeVarintField(2, (ulong)(int)unknown);
                   }
                   break;
                 }
@@ -602,25 +602,23 @@
               if (unknownFields == null) {
                 unknownFields = pb::UnknownFieldSet.CreateBuilder(this.UnknownFields);
               }
-              ParseUnknownField(input, unknownFields, extensionRegistry, tag);
+              ParseUnknownField(input, unknownFields, extensionRegistry, tag, field_name);
               break;
             }
             case 10: {
-              Name = input.ReadString();
+              result.hasName |= input.ReadString(ref result.name_);
               break;
             }
             case 16: {
-              Id = input.ReadInt32();
+              result.hasId |= input.ReadInt32(ref result.id_);
               break;
             }
             case 26: {
-              Email = input.ReadString();
+              result.hasEmail |= input.ReadString(ref result.email_);
               break;
             }
             case 34: {
-              global::Google.ProtocolBuffers.Examples.AddressBook.Person.Types.PhoneNumber.Builder subBuilder = global::Google.ProtocolBuffers.Examples.AddressBook.Person.Types.PhoneNumber.CreateBuilder();
-              input.ReadMessage(subBuilder, extensionRegistry);
-              AddPhone(subBuilder.BuildPartial());
+              input.ReadMessageArray(tag, field_name, result.phone_, global::Google.ProtocolBuffers.Examples.AddressBook.Person.Types.PhoneNumber.DefaultInstance, extensionRegistry);
               break;
             }
           }
@@ -922,13 +920,11 @@
               if (unknownFields == null) {
                 unknownFields = pb::UnknownFieldSet.CreateBuilder(this.UnknownFields);
               }
-              ParseUnknownField(input, unknownFields, extensionRegistry, tag);
+              ParseUnknownField(input, unknownFields, extensionRegistry, tag, field_name);
               break;
             }
             case 10: {
-              global::Google.ProtocolBuffers.Examples.AddressBook.Person.Builder subBuilder = global::Google.ProtocolBuffers.Examples.AddressBook.Person.CreateBuilder();
-              input.ReadMessage(subBuilder, extensionRegistry);
-              AddPerson(subBuilder.BuildPartial());
+              input.ReadMessageArray(tag, field_name, result.person_, global::Google.ProtocolBuffers.Examples.AddressBook.Person.DefaultInstance, extensionRegistry);
               break;
             }
           }
diff --git a/src/ProtoGen/EnumFieldGenerator.cs b/src/ProtoGen/EnumFieldGenerator.cs
index 651d7db..3e9e071 100644
--- a/src/ProtoGen/EnumFieldGenerator.cs
+++ b/src/ProtoGen/EnumFieldGenerator.cs
@@ -95,19 +95,32 @@
 
         public void GenerateParsingCode(TextGenerator writer)
         {
-            // TODO(jonskeet): Make a more efficient way of doing this
-            writer.WriteLine("int rawValue = input.ReadEnum();");
-            writer.WriteLine("if (!global::System.Enum.IsDefined(typeof({0}), rawValue)) {{", TypeName);
+            writer.WriteLine("object unknown;");
+            writer.WriteLine("if(input.ReadEnum(ref result.{0}_, out unknown)) {{", Name);
+            writer.WriteLine("  result.has{0} = true;", PropertyName);
+            writer.WriteLine("} else if(unknown is int) {");
             if (!UseLiteRuntime)
             {
                 writer.WriteLine("  if (unknownFields == null) {"); // First unknown field - create builder now
                 writer.WriteLine("    unknownFields = pb::UnknownFieldSet.CreateBuilder(this.UnknownFields);");
                 writer.WriteLine("  }");
-                writer.WriteLine("  unknownFields.MergeVarintField({0}, (ulong) rawValue);", Number);
+                writer.WriteLine("  unknownFields.MergeVarintField({0}, (ulong)(int)unknown);", Number);
             }
-            writer.WriteLine("} else {");
-            writer.WriteLine("  {0} = ({1}) rawValue;", PropertyName, TypeName);
             writer.WriteLine("}");
+
+            // TO DO(jonskeet): Make a more efficient way of doing this
+            //writer.WriteLine("int rawValue = input.ReadEnum();");
+            //writer.WriteLine("if (!global::System.Enum.IsDefined(typeof({0}), rawValue)) {{", TypeName);
+            //if (!UseLiteRuntime)
+            //{
+            //    writer.WriteLine("  if (unknownFields == null) {"); // First unknown field - create builder now
+            //    writer.WriteLine("    unknownFields = pb::UnknownFieldSet.CreateBuilder(this.UnknownFields);");
+            //    writer.WriteLine("  }");
+            //    writer.WriteLine("  unknownFields.MergeVarintField({0}, (ulong) rawValue);", Number);
+            //}
+            //writer.WriteLine("} else {");
+            //writer.WriteLine("  {0} = ({1}) rawValue;", PropertyName, TypeName);
+            //writer.WriteLine("}");
         }
 
         public void GenerateSerializationCode(TextGenerator writer)
diff --git a/src/ProtoGen/MessageGenerator.cs b/src/ProtoGen/MessageGenerator.cs
index 94008fb..228dcf8 100644
--- a/src/ProtoGen/MessageGenerator.cs
+++ b/src/ProtoGen/MessageGenerator.cs
@@ -647,7 +647,7 @@
                 writer.WriteLine("    unknownFields = pb::UnknownFieldSet.CreateBuilder(this.UnknownFields);");
                 writer.WriteLine("  }");
             }
-            writer.WriteLine("  ParseUnknownField(input, {0}extensionRegistry, tag);",
+            writer.WriteLine("  ParseUnknownField(input, {0}extensionRegistry, tag, field_name);",
                              UseLiteRuntime ? "" : "unknownFields, ");
             writer.WriteLine("  break;");
             writer.WriteLine("}");
diff --git a/src/ProtoGen/PrimitiveFieldGenerator.cs b/src/ProtoGen/PrimitiveFieldGenerator.cs
index ad0ab8d..2e767b9 100644
--- a/src/ProtoGen/PrimitiveFieldGenerator.cs
+++ b/src/ProtoGen/PrimitiveFieldGenerator.cs
@@ -97,7 +97,7 @@
 
         public void GenerateParsingCode(TextGenerator writer)
         {
-            writer.WriteLine("{0} = input.Read{1}();", PropertyName, CapitalizedTypeName);
+            writer.WriteLine("result.has{0} |= input.Read{1}(ref result.{2}_);", PropertyName, CapitalizedTypeName, Name);
         }
 
         public void GenerateSerializationCode(TextGenerator writer)
diff --git a/src/ProtoGen/RepeatedEnumFieldGenerator.cs b/src/ProtoGen/RepeatedEnumFieldGenerator.cs
index e3fdd65..27aabf5 100644
--- a/src/ProtoGen/RepeatedEnumFieldGenerator.cs
+++ b/src/ProtoGen/RepeatedEnumFieldGenerator.cs
@@ -112,36 +112,50 @@
 
         public void GenerateParsingCode(TextGenerator writer)
         {
-            // If packed, set up the while loop
-            if (Descriptor.IsPacked)
-            {
-                writer.WriteLine("int length = input.ReadInt32();");
-                writer.WriteLine("int oldLimit = input.PushLimit(length);");
-                writer.WriteLine("while (!input.ReachedLimit) {");
-                writer.Indent();
-            }
-
-            // Read and store the enum
-            // TODO(jonskeet): Make a more efficient way of doing this
-            writer.WriteLine("int rawValue = input.ReadEnum();");
-            writer.WriteLine("if (!global::System.Enum.IsDefined(typeof({0}), rawValue)) {{", TypeName);
+            writer.WriteLine("scg::ICollection<object> unknownItems;");
+            writer.WriteLine("input.ReadEnumArray<{0}>(tag, field_name, result.{1}_, out unknownItems);", TypeName, Name);
             if (!UseLiteRuntime)
             {
-                writer.WriteLine("  if (unknownFields == null) {"); // First unknown field - create builder now
+                writer.WriteLine("if (unknownItems != null) {");
+                writer.WriteLine("  if (unknownFields == null) {");
                 writer.WriteLine("    unknownFields = pb::UnknownFieldSet.CreateBuilder(this.UnknownFields);");
                 writer.WriteLine("  }");
-                writer.WriteLine("  unknownFields.MergeVarintField({0}, (ulong) rawValue);", Number);
-            }
-            writer.WriteLine("} else {");
-            writer.WriteLine("  Add{0}(({1}) rawValue);", PropertyName, TypeName);
-            writer.WriteLine("}");
-
-            if (Descriptor.IsPacked)
-            {
-                writer.Outdent();
+                writer.WriteLine("  foreach (object rawValue in unknownItems)");
+                writer.WriteLine("    if (rawValue is int)");
+                writer.WriteLine("      unknownFields.MergeVarintField({0}, (ulong)(int)rawValue);", Number);
                 writer.WriteLine("}");
-                writer.WriteLine("input.PopLimit(oldLimit);");
             }
+
+            //// If packed, set up the while loop
+            //if (Descriptor.IsPacked)
+            //{
+            //    writer.WriteLine("int length = input.ReadInt32();");
+            //    writer.WriteLine("int oldLimit = input.PushLimit(length);");
+            //    writer.WriteLine("while (!input.ReachedLimit) {");
+            //    writer.Indent();
+            //}
+
+            //// Read and store the enum
+            //// TO DO(jonskeet): Make a more efficient way of doing this
+            //writer.WriteLine("int rawValue = input.ReadEnum();");
+            //writer.WriteLine("if (!global::System.Enum.IsDefined(typeof({0}), rawValue)) {{", TypeName);
+            //if (!UseLiteRuntime)
+            //{
+            //    writer.WriteLine("  if (unknownFields == null) {"); // First unknown field - create builder now
+            //    writer.WriteLine("    unknownFields = pb::UnknownFieldSet.CreateBuilder(this.UnknownFields);");
+            //    writer.WriteLine("  }");
+            //    writer.WriteLine("  unknownFields.MergeVarintField({0}, (ulong) rawValue);", Number);
+            //}
+            //writer.WriteLine("} else {");
+            //writer.WriteLine("  Add{0}(({1}) rawValue);", PropertyName, TypeName);
+            //writer.WriteLine("}");
+
+            //if (Descriptor.IsPacked)
+            //{
+            //    writer.Outdent();
+            //    writer.WriteLine("}");
+            //    writer.WriteLine("input.PopLimit(oldLimit);");
+            //}
         }
 
         public void GenerateSerializationCode(TextGenerator writer)
diff --git a/src/ProtoGen/RepeatedMessageFieldGenerator.cs b/src/ProtoGen/RepeatedMessageFieldGenerator.cs
index 84e92e0..23f06a1 100644
--- a/src/ProtoGen/RepeatedMessageFieldGenerator.cs
+++ b/src/ProtoGen/RepeatedMessageFieldGenerator.cs
@@ -34,6 +34,7 @@
 
 #endregion
 
+using System;
 using Google.ProtocolBuffers.Descriptors;
 
 namespace Google.ProtocolBuffers.ProtoGen
@@ -121,16 +122,18 @@
 
         public void GenerateParsingCode(TextGenerator writer)
         {
-            writer.WriteLine("{0}.Builder subBuilder = {0}.CreateBuilder();", TypeName);
-            if (Descriptor.FieldType == FieldType.Group)
-            {
-                writer.WriteLine("input.ReadGroup({0}, subBuilder, extensionRegistry);", Number);
-            }
-            else
-            {
-                writer.WriteLine("input.ReadMessage(subBuilder, extensionRegistry);");
-            }
-            writer.WriteLine("Add{0}(subBuilder.BuildPartial());", PropertyName);
+            writer.WriteLine("input.Read{0}Array(tag, field_name, result.{1}_, {2}.DefaultInstance, extensionRegistry);", MessageOrGroup, Name, TypeName);
+      
+            //writer.WriteLine("{0}.Builder subBuilder = {0}.CreateBuilder();", TypeName);
+            //if (Descriptor.FieldType == FieldType.Group)
+            //{
+            //    writer.WriteLine("input.ReadGroup({0}, subBuilder, extensionRegistry);", Number);
+            //}
+            //else
+            //{
+            //    writer.WriteLine("input.ReadMessage(subBuilder, extensionRegistry);");
+            //}
+            //writer.WriteLine("Add{0}(subBuilder.BuildPartial());", PropertyName);
         }
 
         public void GenerateSerializationCode(TextGenerator writer)
diff --git a/src/ProtoGen/RepeatedPrimitiveFieldGenerator.cs b/src/ProtoGen/RepeatedPrimitiveFieldGenerator.cs
index 64b95e1..d653628 100644
--- a/src/ProtoGen/RepeatedPrimitiveFieldGenerator.cs
+++ b/src/ProtoGen/RepeatedPrimitiveFieldGenerator.cs
@@ -121,19 +121,20 @@
 
         public void GenerateParsingCode(TextGenerator writer)
         {
-            if (Descriptor.IsPacked)
-            {
-                writer.WriteLine("int length = input.ReadInt32();");
-                writer.WriteLine("int limit = input.PushLimit(length);");
-                writer.WriteLine("while (!input.ReachedLimit) {");
-                writer.WriteLine("  Add{0}(input.Read{1}());", PropertyName, CapitalizedTypeName);
-                writer.WriteLine("}");
-                writer.WriteLine("input.PopLimit(limit);");
-            }
-            else
-            {
-                writer.WriteLine("Add{0}(input.Read{1}());", PropertyName, CapitalizedTypeName);
-            }
+            writer.WriteLine("input.ReadPrimitiveArray(pbd::FieldType.{1}, tag, field_name, result.{0}_);", Name, Descriptor.FieldType);
+            //if (Descriptor.IsPacked)
+            //{
+            //    writer.WriteLine("int length = input.ReadInt32();");
+            //    writer.WriteLine("int limit = input.PushLimit(length);");
+            //    writer.WriteLine("while (!input.ReachedLimit) {");
+            //    writer.WriteLine("  Add{0}(input.Read{1}());", PropertyName, CapitalizedTypeName);
+            //    writer.WriteLine("}");
+            //    writer.WriteLine("input.PopLimit(limit);");
+            //}
+            //else
+            //{
+            //    writer.WriteLine("Add{0}(input.Read{1}());", PropertyName, CapitalizedTypeName);
+            //}
         }
 
         public void GenerateSerializationCode(TextGenerator writer)
diff --git a/src/ProtocolBuffers.Test/CodedInputStreamTest.cs b/src/ProtocolBuffers.Test/CodedInputStreamTest.cs
index a49b1ed..c3ca0a1 100644
--- a/src/ProtocolBuffers.Test/CodedInputStreamTest.cs
+++ b/src/ProtocolBuffers.Test/CodedInputStreamTest.cs
@@ -362,7 +362,8 @@
 
             try
             {
-                input.ReadBytes();
+                ByteString bytes = null;
+                input.ReadBytes(ref bytes);
                 Assert.Fail("Should have thrown an exception!");
             }
             catch (InvalidProtocolBufferException)
@@ -506,7 +507,8 @@
 
             Assert.IsTrue(input.ReadTag(out testtag, out ignored));
             Assert.AreEqual(tag, testtag);
-            string text = input.ReadString();
+            string text = null;
+            input.ReadString(ref text);
             Assert.AreEqual('\ufffd', text[0]);
         }
 
diff --git a/src/ProtocolBuffers.Test/TestProtos/UnitTestCSharpOptionsProtoFile.cs b/src/ProtocolBuffers.Test/TestProtos/UnitTestCSharpOptionsProtoFile.cs
index 79567d2..55f52f7 100644
--- a/src/ProtocolBuffers.Test/TestProtos/UnitTestCSharpOptionsProtoFile.cs
+++ b/src/ProtocolBuffers.Test/TestProtos/UnitTestCSharpOptionsProtoFile.cs
@@ -276,19 +276,19 @@
               if (unknownFields == null) {
                 unknownFields = pb::UnknownFieldSet.CreateBuilder(this.UnknownFields);
               }
-              ParseUnknownField(input, unknownFields, extensionRegistry, tag);
+              ParseUnknownField(input, unknownFields, extensionRegistry, tag, field_name);
               break;
             }
             case 10: {
-              Normal = input.ReadString();
+              result.hasNormal |= input.ReadString(ref result.normal_);
               break;
             }
             case 18: {
-              OptionsMessage_ = input.ReadString();
+              result.hasOptionsMessage_ |= input.ReadString(ref result.optionsMessage_);
               break;
             }
             case 26: {
-              CustomName = input.ReadString();
+              result.hasCustomName |= input.ReadString(ref result.customized_);
               break;
             }
           }
diff --git a/src/ProtocolBuffers.Test/TestProtos/UnitTestCustomOptionsProtoFile.cs b/src/ProtocolBuffers.Test/TestProtos/UnitTestCustomOptionsProtoFile.cs
index 73a1781..96c8a76 100644
--- a/src/ProtocolBuffers.Test/TestProtos/UnitTestCustomOptionsProtoFile.cs
+++ b/src/ProtocolBuffers.Test/TestProtos/UnitTestCustomOptionsProtoFile.cs
@@ -593,11 +593,11 @@
               if (unknownFields == null) {
                 unknownFields = pb::UnknownFieldSet.CreateBuilder(this.UnknownFields);
               }
-              ParseUnknownField(input, unknownFields, extensionRegistry, tag);
+              ParseUnknownField(input, unknownFields, extensionRegistry, tag, field_name);
               break;
             }
             case 10: {
-              Field1 = input.ReadString();
+              result.hasField1 |= input.ReadString(ref result.field1_);
               break;
             }
           }
@@ -799,7 +799,7 @@
               if (unknownFields == null) {
                 unknownFields = pb::UnknownFieldSet.CreateBuilder(this.UnknownFields);
               }
-              ParseUnknownField(input, unknownFields, extensionRegistry, tag);
+              ParseUnknownField(input, unknownFields, extensionRegistry, tag, field_name);
               break;
             }
           }
@@ -982,7 +982,7 @@
               if (unknownFields == null) {
                 unknownFields = pb::UnknownFieldSet.CreateBuilder(this.UnknownFields);
               }
-              ParseUnknownField(input, unknownFields, extensionRegistry, tag);
+              ParseUnknownField(input, unknownFields, extensionRegistry, tag, field_name);
               break;
             }
           }
@@ -1180,7 +1180,7 @@
               if (unknownFields == null) {
                 unknownFields = pb::UnknownFieldSet.CreateBuilder(this.UnknownFields);
               }
-              ParseUnknownField(input, unknownFields, extensionRegistry, tag);
+              ParseUnknownField(input, unknownFields, extensionRegistry, tag, field_name);
               break;
             }
           }
@@ -1363,7 +1363,7 @@
               if (unknownFields == null) {
                 unknownFields = pb::UnknownFieldSet.CreateBuilder(this.UnknownFields);
               }
-              ParseUnknownField(input, unknownFields, extensionRegistry, tag);
+              ParseUnknownField(input, unknownFields, extensionRegistry, tag, field_name);
               break;
             }
           }
@@ -1546,7 +1546,7 @@
               if (unknownFields == null) {
                 unknownFields = pb::UnknownFieldSet.CreateBuilder(this.UnknownFields);
               }
-              ParseUnknownField(input, unknownFields, extensionRegistry, tag);
+              ParseUnknownField(input, unknownFields, extensionRegistry, tag, field_name);
               break;
             }
           }
@@ -1729,7 +1729,7 @@
               if (unknownFields == null) {
                 unknownFields = pb::UnknownFieldSet.CreateBuilder(this.UnknownFields);
               }
-              ParseUnknownField(input, unknownFields, extensionRegistry, tag);
+              ParseUnknownField(input, unknownFields, extensionRegistry, tag, field_name);
               break;
             }
           }
@@ -1912,7 +1912,7 @@
               if (unknownFields == null) {
                 unknownFields = pb::UnknownFieldSet.CreateBuilder(this.UnknownFields);
               }
-              ParseUnknownField(input, unknownFields, extensionRegistry, tag);
+              ParseUnknownField(input, unknownFields, extensionRegistry, tag, field_name);
               break;
             }
           }
@@ -2095,7 +2095,7 @@
               if (unknownFields == null) {
                 unknownFields = pb::UnknownFieldSet.CreateBuilder(this.UnknownFields);
               }
-              ParseUnknownField(input, unknownFields, extensionRegistry, tag);
+              ParseUnknownField(input, unknownFields, extensionRegistry, tag, field_name);
               break;
             }
           }
@@ -2278,7 +2278,7 @@
               if (unknownFields == null) {
                 unknownFields = pb::UnknownFieldSet.CreateBuilder(this.UnknownFields);
               }
-              ParseUnknownField(input, unknownFields, extensionRegistry, tag);
+              ParseUnknownField(input, unknownFields, extensionRegistry, tag, field_name);
               break;
             }
           }
@@ -2523,19 +2523,19 @@
               if (unknownFields == null) {
                 unknownFields = pb::UnknownFieldSet.CreateBuilder(this.UnknownFields);
               }
-              ParseUnknownField(input, unknownFields, extensionRegistry, tag);
+              ParseUnknownField(input, unknownFields, extensionRegistry, tag, field_name);
               break;
             }
             case 8: {
-              Foo = input.ReadInt32();
+              result.hasFoo |= input.ReadInt32(ref result.foo_);
               break;
             }
             case 16: {
-              Foo2 = input.ReadInt32();
+              result.hasFoo2 |= input.ReadInt32(ref result.foo2_);
               break;
             }
             case 24: {
-              Foo3 = input.ReadInt32();
+              result.hasFoo3 |= input.ReadInt32(ref result.foo3_);
               break;
             }
           }
@@ -2823,11 +2823,11 @@
                   if (unknownFields == null) {
                     unknownFields = pb::UnknownFieldSet.CreateBuilder(this.UnknownFields);
                   }
-                  ParseUnknownField(input, unknownFields, extensionRegistry, tag);
+                  ParseUnknownField(input, unknownFields, extensionRegistry, tag, field_name);
                   break;
                 }
                 case 8: {
-                  Waldo = input.ReadInt32();
+                  result.hasWaldo |= input.ReadInt32(ref result.waldo_);
                   break;
                 }
               }
@@ -3071,7 +3071,7 @@
               if (unknownFields == null) {
                 unknownFields = pb::UnknownFieldSet.CreateBuilder(this.UnknownFields);
               }
-              ParseUnknownField(input, unknownFields, extensionRegistry, tag);
+              ParseUnknownField(input, unknownFields, extensionRegistry, tag, field_name);
               break;
             }
             case 10: {
@@ -3084,7 +3084,7 @@
               break;
             }
             case 16: {
-              Baz = input.ReadInt32();
+              result.hasBaz |= input.ReadInt32(ref result.baz_);
               break;
             }
             case 26: {
@@ -3415,11 +3415,11 @@
                   if (unknownFields == null) {
                     unknownFields = pb::UnknownFieldSet.CreateBuilder(this.UnknownFields);
                   }
-                  ParseUnknownField(input, unknownFields, extensionRegistry, tag);
+                  ParseUnknownField(input, unknownFields, extensionRegistry, tag, field_name);
                   break;
                 }
                 case 24: {
-                  Plugh = input.ReadInt32();
+                  result.hasPlugh |= input.ReadInt32(ref result.plugh_);
                   break;
                 }
               }
@@ -3636,11 +3636,11 @@
               if (unknownFields == null) {
                 unknownFields = pb::UnknownFieldSet.CreateBuilder(this.UnknownFields);
               }
-              ParseUnknownField(input, unknownFields, extensionRegistry, tag);
+              ParseUnknownField(input, unknownFields, extensionRegistry, tag, field_name);
               break;
             }
             case 8: {
-              Qux = input.ReadInt32();
+              result.hasQux |= input.ReadInt32(ref result.qux_);
               break;
             }
             case 19: {
@@ -3905,11 +3905,11 @@
               if (unknownFields == null) {
                 unknownFields = pb::UnknownFieldSet.CreateBuilder(this.UnknownFields);
               }
-              ParseUnknownField(input, unknownFields, extensionRegistry, tag);
+              ParseUnknownField(input, unknownFields, extensionRegistry, tag, field_name);
               break;
             }
             case 60751608: {
-              Xyzzy = input.ReadInt32();
+              result.hasXyzzy |= input.ReadInt32(ref result.xyzzy_);
               break;
             }
           }
@@ -4110,7 +4110,7 @@
               if (unknownFields == null) {
                 unknownFields = pb::UnknownFieldSet.CreateBuilder(this.UnknownFields);
               }
-              ParseUnknownField(input, unknownFields, extensionRegistry, tag);
+              ParseUnknownField(input, unknownFields, extensionRegistry, tag, field_name);
               break;
             }
           }
diff --git a/src/ProtocolBuffers.Test/TestProtos/UnitTestEmbedOptimizeForProtoFile.cs b/src/ProtocolBuffers.Test/TestProtos/UnitTestEmbedOptimizeForProtoFile.cs
index 5f1d1a8..9993960 100644
--- a/src/ProtocolBuffers.Test/TestProtos/UnitTestEmbedOptimizeForProtoFile.cs
+++ b/src/ProtocolBuffers.Test/TestProtos/UnitTestEmbedOptimizeForProtoFile.cs
@@ -270,7 +270,7 @@
               if (unknownFields == null) {
                 unknownFields = pb::UnknownFieldSet.CreateBuilder(this.UnknownFields);
               }
-              ParseUnknownField(input, unknownFields, extensionRegistry, tag);
+              ParseUnknownField(input, unknownFields, extensionRegistry, tag, field_name);
               break;
             }
             case 10: {
@@ -283,9 +283,7 @@
               break;
             }
             case 18: {
-              global::Google.ProtocolBuffers.TestProtos.TestOptimizedForSize.Builder subBuilder = global::Google.ProtocolBuffers.TestProtos.TestOptimizedForSize.CreateBuilder();
-              input.ReadMessage(subBuilder, extensionRegistry);
-              AddRepeatedMessage(subBuilder.BuildPartial());
+              input.ReadMessageArray(tag, field_name, result.repeatedMessage_, global::Google.ProtocolBuffers.TestProtos.TestOptimizedForSize.DefaultInstance, extensionRegistry);
               break;
             }
           }
diff --git a/src/ProtocolBuffers.Test/TestProtos/UnitTestGoogleSpeedProtoFile.cs b/src/ProtocolBuffers.Test/TestProtos/UnitTestGoogleSpeedProtoFile.cs
index 7e0f7d1..757ecff 100644
--- a/src/ProtocolBuffers.Test/TestProtos/UnitTestGoogleSpeedProtoFile.cs
+++ b/src/ProtocolBuffers.Test/TestProtos/UnitTestGoogleSpeedProtoFile.cs
@@ -1086,51 +1086,51 @@
               if (unknownFields == null) {
                 unknownFields = pb::UnknownFieldSet.CreateBuilder(this.UnknownFields);
               }
-              ParseUnknownField(input, unknownFields, extensionRegistry, tag);
+              ParseUnknownField(input, unknownFields, extensionRegistry, tag, field_name);
               break;
             }
             case 10: {
-              Field1 = input.ReadString();
+              result.hasField1 |= input.ReadString(ref result.field1_);
               break;
             }
             case 16: {
-              Field2 = input.ReadInt32();
+              result.hasField2 |= input.ReadInt32(ref result.field2_);
               break;
             }
             case 24: {
-              Field3 = input.ReadInt32();
+              result.hasField3 |= input.ReadInt32(ref result.field3_);
               break;
             }
             case 34: {
-              Field4 = input.ReadString();
+              result.hasField4 |= input.ReadString(ref result.field4_);
               break;
             }
             case 41: {
-              AddField5(input.ReadFixed64());
+              input.ReadPrimitiveArray(pbd::FieldType.Fixed64, tag, field_name, result.field5_);
               break;
             }
             case 48: {
-              Field6 = input.ReadInt32();
+              result.hasField6 |= input.ReadInt32(ref result.field6_);
               break;
             }
             case 58: {
-              Field7 = input.ReadString();
+              result.hasField7 |= input.ReadString(ref result.field7_);
               break;
             }
             case 74: {
-              Field9 = input.ReadString();
+              result.hasField9 |= input.ReadString(ref result.field9_);
               break;
             }
             case 96: {
-              Field12 = input.ReadBool();
+              result.hasField12 |= input.ReadBool(ref result.field12_);
               break;
             }
             case 104: {
-              Field13 = input.ReadBool();
+              result.hasField13 |= input.ReadBool(ref result.field13_);
               break;
             }
             case 112: {
-              Field14 = input.ReadBool();
+              result.hasField14 |= input.ReadBool(ref result.field14_);
               break;
             }
             case 122: {
@@ -1143,119 +1143,119 @@
               break;
             }
             case 128: {
-              Field16 = input.ReadInt32();
+              result.hasField16 |= input.ReadInt32(ref result.field16_);
               break;
             }
             case 136: {
-              Field17 = input.ReadBool();
+              result.hasField17 |= input.ReadBool(ref result.field17_);
               break;
             }
             case 146: {
-              Field18 = input.ReadString();
+              result.hasField18 |= input.ReadString(ref result.field18_);
               break;
             }
             case 176: {
-              Field22 = input.ReadInt64();
+              result.hasField22 |= input.ReadInt64(ref result.field22_);
               break;
             }
             case 184: {
-              Field23 = input.ReadInt32();
+              result.hasField23 |= input.ReadInt32(ref result.field23_);
               break;
             }
             case 192: {
-              Field24 = input.ReadBool();
+              result.hasField24 |= input.ReadBool(ref result.field24_);
               break;
             }
             case 200: {
-              Field25 = input.ReadInt32();
+              result.hasField25 |= input.ReadInt32(ref result.field25_);
               break;
             }
             case 232: {
-              Field29 = input.ReadInt32();
+              result.hasField29 |= input.ReadInt32(ref result.field29_);
               break;
             }
             case 240: {
-              Field30 = input.ReadBool();
+              result.hasField30 |= input.ReadBool(ref result.field30_);
               break;
             }
             case 472: {
-              Field59 = input.ReadBool();
+              result.hasField59 |= input.ReadBool(ref result.field59_);
               break;
             }
             case 480: {
-              Field60 = input.ReadInt32();
+              result.hasField60 |= input.ReadInt32(ref result.field60_);
               break;
             }
             case 536: {
-              Field67 = input.ReadInt32();
+              result.hasField67 |= input.ReadInt32(ref result.field67_);
               break;
             }
             case 544: {
-              Field68 = input.ReadInt32();
+              result.hasField68 |= input.ReadInt32(ref result.field68_);
               break;
             }
             case 624: {
-              Field78 = input.ReadBool();
+              result.hasField78 |= input.ReadBool(ref result.field78_);
               break;
             }
             case 640: {
-              Field80 = input.ReadBool();
+              result.hasField80 |= input.ReadBool(ref result.field80_);
               break;
             }
             case 648: {
-              Field81 = input.ReadBool();
+              result.hasField81 |= input.ReadBool(ref result.field81_);
               break;
             }
             case 800: {
-              Field100 = input.ReadInt32();
+              result.hasField100 |= input.ReadInt32(ref result.field100_);
               break;
             }
             case 808: {
-              Field101 = input.ReadInt32();
+              result.hasField101 |= input.ReadInt32(ref result.field101_);
               break;
             }
             case 818: {
-              Field102 = input.ReadString();
+              result.hasField102 |= input.ReadString(ref result.field102_);
               break;
             }
             case 826: {
-              Field103 = input.ReadString();
+              result.hasField103 |= input.ReadString(ref result.field103_);
               break;
             }
             case 832: {
-              Field104 = input.ReadInt32();
+              result.hasField104 |= input.ReadInt32(ref result.field104_);
               break;
             }
             case 1024: {
-              Field128 = input.ReadInt32();
+              result.hasField128 |= input.ReadInt32(ref result.field128_);
               break;
             }
             case 1034: {
-              Field129 = input.ReadString();
+              result.hasField129 |= input.ReadString(ref result.field129_);
               break;
             }
             case 1040: {
-              Field130 = input.ReadInt32();
+              result.hasField130 |= input.ReadInt32(ref result.field130_);
               break;
             }
             case 1048: {
-              Field131 = input.ReadInt32();
+              result.hasField131 |= input.ReadInt32(ref result.field131_);
               break;
             }
             case 1200: {
-              Field150 = input.ReadInt32();
+              result.hasField150 |= input.ReadInt32(ref result.field150_);
               break;
             }
             case 2168: {
-              Field271 = input.ReadInt32();
+              result.hasField271 |= input.ReadInt32(ref result.field271_);
               break;
             }
             case 2176: {
-              Field272 = input.ReadInt32();
+              result.hasField272 |= input.ReadInt32(ref result.field272_);
               break;
             }
             case 2240: {
-              Field280 = input.ReadInt32();
+              result.hasField280 |= input.ReadInt32(ref result.field280_);
               break;
             }
           }
@@ -2599,87 +2599,87 @@
               if (unknownFields == null) {
                 unknownFields = pb::UnknownFieldSet.CreateBuilder(this.UnknownFields);
               }
-              ParseUnknownField(input, unknownFields, extensionRegistry, tag);
+              ParseUnknownField(input, unknownFields, extensionRegistry, tag, field_name);
               break;
             }
             case 8: {
-              Field1 = input.ReadInt32();
+              result.hasField1 |= input.ReadInt32(ref result.field1_);
               break;
             }
             case 16: {
-              Field2 = input.ReadInt32();
+              result.hasField2 |= input.ReadInt32(ref result.field2_);
               break;
             }
             case 24: {
-              Field3 = input.ReadInt32();
+              result.hasField3 |= input.ReadInt32(ref result.field3_);
               break;
             }
             case 96: {
-              Field12 = input.ReadBool();
+              result.hasField12 |= input.ReadBool(ref result.field12_);
               break;
             }
             case 104: {
-              Field13 = input.ReadInt64();
+              result.hasField13 |= input.ReadInt64(ref result.field13_);
               break;
             }
             case 112: {
-              Field14 = input.ReadInt64();
+              result.hasField14 |= input.ReadInt64(ref result.field14_);
               break;
             }
             case 122: {
-              Field15 = input.ReadString();
+              result.hasField15 |= input.ReadString(ref result.field15_);
               break;
             }
             case 128: {
-              Field16 = input.ReadInt32();
+              result.hasField16 |= input.ReadInt32(ref result.field16_);
               break;
             }
             case 152: {
-              Field19 = input.ReadInt32();
+              result.hasField19 |= input.ReadInt32(ref result.field19_);
               break;
             }
             case 160: {
-              Field20 = input.ReadBool();
+              result.hasField20 |= input.ReadBool(ref result.field20_);
               break;
             }
             case 169: {
-              Field21 = input.ReadFixed64();
+              result.hasField21 |= input.ReadFixed64(ref result.field21_);
               break;
             }
             case 176: {
-              Field22 = input.ReadInt32();
+              result.hasField22 |= input.ReadInt32(ref result.field22_);
               break;
             }
             case 184: {
-              Field23 = input.ReadBool();
+              result.hasField23 |= input.ReadBool(ref result.field23_);
               break;
             }
             case 224: {
-              Field28 = input.ReadBool();
+              result.hasField28 |= input.ReadBool(ref result.field28_);
               break;
             }
             case 1629: {
-              Field203 = input.ReadFixed32();
+              result.hasField203 |= input.ReadFixed32(ref result.field203_);
               break;
             }
             case 1632: {
-              Field204 = input.ReadInt32();
+              result.hasField204 |= input.ReadInt32(ref result.field204_);
               break;
             }
             case 1642: {
-              Field205 = input.ReadString();
+              result.hasField205 |= input.ReadString(ref result.field205_);
               break;
             }
             case 1648: {
-              Field206 = input.ReadBool();
+              result.hasField206 |= input.ReadBool(ref result.field206_);
               break;
             }
             case 1656: {
-              Field207 = input.ReadUInt64();
+              result.hasField207 |= input.ReadUInt64(ref result.field207_);
               break;
             }
             case 2400: {
-              Field300 = input.ReadUInt64();
+              result.hasField300 |= input.ReadUInt64(ref result.field300_);
               break;
             }
           }
@@ -3593,63 +3593,63 @@
                   if (unknownFields == null) {
                     unknownFields = pb::UnknownFieldSet.CreateBuilder(this.UnknownFields);
                   }
-                  ParseUnknownField(input, unknownFields, extensionRegistry, tag);
+                  ParseUnknownField(input, unknownFields, extensionRegistry, tag, field_name);
                   break;
                 }
                 case 40: {
-                  Field5 = input.ReadInt32();
+                  result.hasField5 |= input.ReadInt32(ref result.field5_);
                   break;
                 }
                 case 93: {
-                  Field11 = input.ReadFloat();
+                  result.hasField11 |= input.ReadFloat(ref result.field11_);
                   break;
                 }
                 case 98: {
-                  Field12 = input.ReadString();
+                  result.hasField12 |= input.ReadString(ref result.field12_);
                   break;
                 }
                 case 106: {
-                  Field13 = input.ReadString();
+                  result.hasField13 |= input.ReadString(ref result.field13_);
                   break;
                 }
                 case 114: {
-                  AddField14(input.ReadString());
+                  input.ReadPrimitiveArray(pbd::FieldType.String, tag, field_name, result.field14_);
                   break;
                 }
                 case 120: {
-                  Field15 = input.ReadUInt64();
+                  result.hasField15 |= input.ReadUInt64(ref result.field15_);
                   break;
                 }
                 case 130: {
-                  Field16 = input.ReadString();
+                  result.hasField16 |= input.ReadString(ref result.field16_);
                   break;
                 }
                 case 160: {
-                  Field20 = input.ReadInt32();
+                  result.hasField20 |= input.ReadInt32(ref result.field20_);
                   break;
                 }
                 case 178: {
-                  AddField22(input.ReadString());
+                  input.ReadPrimitiveArray(pbd::FieldType.String, tag, field_name, result.field22_);
                   break;
                 }
                 case 194: {
-                  Field24 = input.ReadString();
+                  result.hasField24 |= input.ReadString(ref result.field24_);
                   break;
                 }
                 case 213: {
-                  Field26 = input.ReadFloat();
+                  result.hasField26 |= input.ReadFloat(ref result.field26_);
                   break;
                 }
                 case 218: {
-                  Field27 = input.ReadString();
+                  result.hasField27 |= input.ReadString(ref result.field27_);
                   break;
                 }
                 case 224: {
-                  Field28 = input.ReadInt32();
+                  result.hasField28 |= input.ReadInt32(ref result.field28_);
                   break;
                 }
                 case 234: {
-                  Field29 = input.ReadString();
+                  result.hasField29 |= input.ReadString(ref result.field29_);
                   break;
                 }
                 case 250: {
@@ -3662,7 +3662,7 @@
                   break;
                 }
                 case 584: {
-                  AddField73(input.ReadInt32());
+                  input.ReadPrimitiveArray(pbd::FieldType.Int32, tag, field_name, result.field73_);
                   break;
                 }
               }
@@ -4762,129 +4762,127 @@
               if (unknownFields == null) {
                 unknownFields = pb::UnknownFieldSet.CreateBuilder(this.UnknownFields);
               }
-              ParseUnknownField(input, unknownFields, extensionRegistry, tag);
+              ParseUnknownField(input, unknownFields, extensionRegistry, tag, field_name);
               break;
             }
             case 10: {
-              Field1 = input.ReadString();
+              result.hasField1 |= input.ReadString(ref result.field1_);
               break;
             }
             case 18: {
-              Field2 = input.ReadBytes();
+              result.hasField2 |= input.ReadBytes(ref result.field2_);
               break;
             }
             case 24: {
-              Field3 = input.ReadInt64();
+              result.hasField3 |= input.ReadInt64(ref result.field3_);
               break;
             }
             case 32: {
-              Field4 = input.ReadInt64();
+              result.hasField4 |= input.ReadInt64(ref result.field4_);
               break;
             }
             case 50: {
-              Field6 = input.ReadString();
+              result.hasField6 |= input.ReadString(ref result.field6_);
               break;
             }
             case 83: {
-              global::Google.ProtocolBuffers.TestProtos.SpeedMessage2.Types.Group1.Builder subBuilder = global::Google.ProtocolBuffers.TestProtos.SpeedMessage2.Types.Group1.CreateBuilder();
-              input.ReadGroup(10, subBuilder, extensionRegistry);
-              AddGroup1(subBuilder.BuildPartial());
+              input.ReadGroupArray(tag, field_name, result.group1_, global::Google.ProtocolBuffers.TestProtos.SpeedMessage2.Types.Group1.DefaultInstance, extensionRegistry);
               break;
             }
             case 168: {
-              Field21 = input.ReadInt32();
+              result.hasField21 |= input.ReadInt32(ref result.field21_);
               break;
             }
             case 205: {
-              Field25 = input.ReadFloat();
+              result.hasField25 |= input.ReadFloat(ref result.field25_);
               break;
             }
             case 240: {
-              Field30 = input.ReadInt64();
+              result.hasField30 |= input.ReadInt64(ref result.field30_);
               break;
             }
             case 504: {
-              Field63 = input.ReadInt32();
+              result.hasField63 |= input.ReadInt32(ref result.field63_);
               break;
             }
             case 568: {
-              Field71 = input.ReadInt32();
+              result.hasField71 |= input.ReadInt32(ref result.field71_);
               break;
             }
             case 600: {
-              Field75 = input.ReadBool();
+              result.hasField75 |= input.ReadBool(ref result.field75_);
               break;
             }
             case 872: {
-              Field109 = input.ReadInt32();
+              result.hasField109 |= input.ReadInt32(ref result.field109_);
               break;
             }
             case 1018: {
-              AddField127(input.ReadString());
+              input.ReadPrimitiveArray(pbd::FieldType.String, tag, field_name, result.field127_);
               break;
             }
             case 1026: {
-              AddField128(input.ReadString());
+              input.ReadPrimitiveArray(pbd::FieldType.String, tag, field_name, result.field128_);
               break;
             }
             case 1032: {
-              Field129 = input.ReadInt32();
+              result.hasField129 |= input.ReadInt32(ref result.field129_);
               break;
             }
             case 1040: {
-              AddField130(input.ReadInt64());
+              input.ReadPrimitiveArray(pbd::FieldType.Int64, tag, field_name, result.field130_);
               break;
             }
             case 1048: {
-              Field131 = input.ReadInt64();
+              result.hasField131 |= input.ReadInt64(ref result.field131_);
               break;
             }
             case 1640: {
-              Field205 = input.ReadBool();
+              result.hasField205 |= input.ReadBool(ref result.field205_);
               break;
             }
             case 1648: {
-              Field206 = input.ReadBool();
+              result.hasField206 |= input.ReadBool(ref result.field206_);
               break;
             }
             case 1680: {
-              Field210 = input.ReadInt32();
+              result.hasField210 |= input.ReadInt32(ref result.field210_);
               break;
             }
             case 1688: {
-              Field211 = input.ReadInt32();
+              result.hasField211 |= input.ReadInt32(ref result.field211_);
               break;
             }
             case 1696: {
-              Field212 = input.ReadInt32();
+              result.hasField212 |= input.ReadInt32(ref result.field212_);
               break;
             }
             case 1704: {
-              Field213 = input.ReadInt32();
+              result.hasField213 |= input.ReadInt32(ref result.field213_);
               break;
             }
             case 1728: {
-              Field216 = input.ReadInt32();
+              result.hasField216 |= input.ReadInt32(ref result.field216_);
               break;
             }
             case 1736: {
-              Field217 = input.ReadInt32();
+              result.hasField217 |= input.ReadInt32(ref result.field217_);
               break;
             }
             case 1744: {
-              Field218 = input.ReadInt32();
+              result.hasField218 |= input.ReadInt32(ref result.field218_);
               break;
             }
             case 1760: {
-              Field220 = input.ReadInt32();
+              result.hasField220 |= input.ReadInt32(ref result.field220_);
               break;
             }
             case 1768: {
-              Field221 = input.ReadInt32();
+              result.hasField221 |= input.ReadInt32(ref result.field221_);
               break;
             }
             case 1781: {
-              Field222 = input.ReadFloat();
+              result.hasField222 |= input.ReadFloat(ref result.field222_);
               break;
             }
           }
@@ -5867,51 +5865,51 @@
               if (unknownFields == null) {
                 unknownFields = pb::UnknownFieldSet.CreateBuilder(this.UnknownFields);
               }
-              ParseUnknownField(input, unknownFields, extensionRegistry, tag);
+              ParseUnknownField(input, unknownFields, extensionRegistry, tag, field_name);
               break;
             }
             case 13: {
-              Field1 = input.ReadFloat();
+              result.hasField1 |= input.ReadFloat(ref result.field1_);
               break;
             }
             case 21: {
-              Field2 = input.ReadFloat();
+              result.hasField2 |= input.ReadFloat(ref result.field2_);
               break;
             }
             case 29: {
-              Field3 = input.ReadFloat();
+              result.hasField3 |= input.ReadFloat(ref result.field3_);
               break;
             }
             case 32: {
-              Field4 = input.ReadBool();
+              result.hasField4 |= input.ReadBool(ref result.field4_);
               break;
             }
             case 40: {
-              Field5 = input.ReadBool();
+              result.hasField5 |= input.ReadBool(ref result.field5_);
               break;
             }
             case 48: {
-              Field6 = input.ReadBool();
+              result.hasField6 |= input.ReadBool(ref result.field6_);
               break;
             }
             case 56: {
-              Field7 = input.ReadBool();
+              result.hasField7 |= input.ReadBool(ref result.field7_);
               break;
             }
             case 69: {
-              Field8 = input.ReadFloat();
+              result.hasField8 |= input.ReadFloat(ref result.field8_);
               break;
             }
             case 72: {
-              Field9 = input.ReadBool();
+              result.hasField9 |= input.ReadBool(ref result.field9_);
               break;
             }
             case 85: {
-              Field10 = input.ReadFloat();
+              result.hasField10 |= input.ReadFloat(ref result.field10_);
               break;
             }
             case 88: {
-              Field11 = input.ReadInt64();
+              result.hasField11 |= input.ReadInt64(ref result.field11_);
               break;
             }
           }
diff --git a/src/ProtocolBuffers.Test/TestProtos/UnitTestImportLiteProtoFile.cs b/src/ProtocolBuffers.Test/TestProtos/UnitTestImportLiteProtoFile.cs
index 26eb96a..0e890f3 100644
--- a/src/ProtocolBuffers.Test/TestProtos/UnitTestImportLiteProtoFile.cs
+++ b/src/ProtocolBuffers.Test/TestProtos/UnitTestImportLiteProtoFile.cs
@@ -218,11 +218,11 @@
               if (pb::WireFormat.IsEndGroupTag(tag)) {
                 return this;
               }
-              ParseUnknownField(input, extensionRegistry, tag);
+              ParseUnknownField(input, extensionRegistry, tag, field_name);
               break;
             }
             case 8: {
-              D = input.ReadInt32();
+              result.hasD |= input.ReadInt32(ref result.d_);
               break;
             }
           }
diff --git a/src/ProtocolBuffers.Test/TestProtos/UnitTestImportProtoFile.cs b/src/ProtocolBuffers.Test/TestProtos/UnitTestImportProtoFile.cs
index d97466d..cbd6cea 100644
--- a/src/ProtocolBuffers.Test/TestProtos/UnitTestImportProtoFile.cs
+++ b/src/ProtocolBuffers.Test/TestProtos/UnitTestImportProtoFile.cs
@@ -249,11 +249,11 @@
               if (unknownFields == null) {
                 unknownFields = pb::UnknownFieldSet.CreateBuilder(this.UnknownFields);
               }
-              ParseUnknownField(input, unknownFields, extensionRegistry, tag);
+              ParseUnknownField(input, unknownFields, extensionRegistry, tag, field_name);
               break;
             }
             case 8: {
-              D = input.ReadInt32();
+              result.hasD |= input.ReadInt32(ref result.d_);
               break;
             }
           }
diff --git a/src/ProtocolBuffers.Test/TestProtos/UnitTestMessageSetProtoFile.cs b/src/ProtocolBuffers.Test/TestProtos/UnitTestMessageSetProtoFile.cs
index 5e5cea7..b41a15d 100644
--- a/src/ProtocolBuffers.Test/TestProtos/UnitTestMessageSetProtoFile.cs
+++ b/src/ProtocolBuffers.Test/TestProtos/UnitTestMessageSetProtoFile.cs
@@ -267,7 +267,7 @@
               if (unknownFields == null) {
                 unknownFields = pb::UnknownFieldSet.CreateBuilder(this.UnknownFields);
               }
-              ParseUnknownField(input, unknownFields, extensionRegistry, tag);
+              ParseUnknownField(input, unknownFields, extensionRegistry, tag, field_name);
               break;
             }
           }
@@ -469,7 +469,7 @@
               if (unknownFields == null) {
                 unknownFields = pb::UnknownFieldSet.CreateBuilder(this.UnknownFields);
               }
-              ParseUnknownField(input, unknownFields, extensionRegistry, tag);
+              ParseUnknownField(input, unknownFields, extensionRegistry, tag, field_name);
               break;
             }
             case 10: {
@@ -718,11 +718,11 @@
               if (unknownFields == null) {
                 unknownFields = pb::UnknownFieldSet.CreateBuilder(this.UnknownFields);
               }
-              ParseUnknownField(input, unknownFields, extensionRegistry, tag);
+              ParseUnknownField(input, unknownFields, extensionRegistry, tag, field_name);
               break;
             }
             case 120: {
-              I = input.ReadInt32();
+              result.hasI |= input.ReadInt32(ref result.i_);
               break;
             }
           }
@@ -944,11 +944,11 @@
               if (unknownFields == null) {
                 unknownFields = pb::UnknownFieldSet.CreateBuilder(this.UnknownFields);
               }
-              ParseUnknownField(input, unknownFields, extensionRegistry, tag);
+              ParseUnknownField(input, unknownFields, extensionRegistry, tag, field_name);
               break;
             }
             case 202: {
-              Str = input.ReadString();
+              result.hasStr |= input.ReadString(ref result.str_);
               break;
             }
           }
@@ -1220,15 +1220,15 @@
                   if (unknownFields == null) {
                     unknownFields = pb::UnknownFieldSet.CreateBuilder(this.UnknownFields);
                   }
-                  ParseUnknownField(input, unknownFields, extensionRegistry, tag);
+                  ParseUnknownField(input, unknownFields, extensionRegistry, tag, field_name);
                   break;
                 }
                 case 16: {
-                  TypeId = input.ReadInt32();
+                  result.hasTypeId |= input.ReadInt32(ref result.typeId_);
                   break;
                 }
                 case 26: {
-                  Message = input.ReadBytes();
+                  result.hasMessage |= input.ReadBytes(ref result.message_);
                   break;
                 }
               }
@@ -1448,13 +1448,11 @@
               if (unknownFields == null) {
                 unknownFields = pb::UnknownFieldSet.CreateBuilder(this.UnknownFields);
               }
-              ParseUnknownField(input, unknownFields, extensionRegistry, tag);
+              ParseUnknownField(input, unknownFields, extensionRegistry, tag, field_name);
               break;
             }
             case 11: {
-              global::Google.ProtocolBuffers.TestProtos.RawMessageSet.Types.Item.Builder subBuilder = global::Google.ProtocolBuffers.TestProtos.RawMessageSet.Types.Item.CreateBuilder();
-              input.ReadGroup(1, subBuilder, extensionRegistry);
-              AddItem(subBuilder.BuildPartial());
+              input.ReadGroupArray(tag, field_name, result.item_, global::Google.ProtocolBuffers.TestProtos.RawMessageSet.Types.Item.DefaultInstance, extensionRegistry);
               break;
             }
           }
diff --git a/src/ProtocolBuffers.Test/TestProtos/UnitTestNoGenericServicesProtoFile.cs b/src/ProtocolBuffers.Test/TestProtos/UnitTestNoGenericServicesProtoFile.cs
index 9897e23..f72688b 100644
--- a/src/ProtocolBuffers.Test/TestProtos/UnitTestNoGenericServicesProtoFile.cs
+++ b/src/ProtocolBuffers.Test/TestProtos/UnitTestNoGenericServicesProtoFile.cs
@@ -264,11 +264,11 @@
               if (unknownFields == null) {
                 unknownFields = pb::UnknownFieldSet.CreateBuilder(this.UnknownFields);
               }
-              ParseUnknownField(input, unknownFields, extensionRegistry, tag);
+              ParseUnknownField(input, unknownFields, extensionRegistry, tag, field_name);
               break;
             }
             case 8: {
-              A = input.ReadInt32();
+              result.hasA |= input.ReadInt32(ref result.a_);
               break;
             }
           }
diff --git a/src/ProtocolBuffers.Test/TestProtos/UnitTestProtoFile.cs b/src/ProtocolBuffers.Test/TestProtos/UnitTestProtoFile.cs
index ce2fbc8..d564a02 100644
--- a/src/ProtocolBuffers.Test/TestProtos/UnitTestProtoFile.cs
+++ b/src/ProtocolBuffers.Test/TestProtos/UnitTestProtoFile.cs
@@ -1246,11 +1246,11 @@
                   if (unknownFields == null) {
                     unknownFields = pb::UnknownFieldSet.CreateBuilder(this.UnknownFields);
                   }
-                  ParseUnknownField(input, unknownFields, extensionRegistry, tag);
+                  ParseUnknownField(input, unknownFields, extensionRegistry, tag, field_name);
                   break;
                 }
                 case 8: {
-                  Bb = input.ReadInt32();
+                  result.hasBb |= input.ReadInt32(ref result.bb_);
                   break;
                 }
               }
@@ -1470,11 +1470,11 @@
                   if (unknownFields == null) {
                     unknownFields = pb::UnknownFieldSet.CreateBuilder(this.UnknownFields);
                   }
-                  ParseUnknownField(input, unknownFields, extensionRegistry, tag);
+                  ParseUnknownField(input, unknownFields, extensionRegistry, tag, field_name);
                   break;
                 }
                 case 136: {
-                  A = input.ReadInt32();
+                  result.hasA |= input.ReadInt32(ref result.a_);
                   break;
                 }
               }
@@ -1694,11 +1694,11 @@
                   if (unknownFields == null) {
                     unknownFields = pb::UnknownFieldSet.CreateBuilder(this.UnknownFields);
                   }
-                  ParseUnknownField(input, unknownFields, extensionRegistry, tag);
+                  ParseUnknownField(input, unknownFields, extensionRegistry, tag, field_name);
                   break;
                 }
                 case 376: {
-                  A = input.ReadInt32();
+                  result.hasA |= input.ReadInt32(ref result.a_);
                   break;
                 }
               }
@@ -3349,67 +3349,67 @@
               if (unknownFields == null) {
                 unknownFields = pb::UnknownFieldSet.CreateBuilder(this.UnknownFields);
               }
-              ParseUnknownField(input, unknownFields, extensionRegistry, tag);
+              ParseUnknownField(input, unknownFields, extensionRegistry, tag, field_name);
               break;
             }
             case 8: {
-              OptionalInt32 = input.ReadInt32();
+              result.hasOptionalInt32 |= input.ReadInt32(ref result.optionalInt32_);
               break;
             }
             case 16: {
-              OptionalInt64 = input.ReadInt64();
+              result.hasOptionalInt64 |= input.ReadInt64(ref result.optionalInt64_);
               break;
             }
             case 24: {
-              OptionalUint32 = input.ReadUInt32();
+              result.hasOptionalUint32 |= input.ReadUInt32(ref result.optionalUint32_);
               break;
             }
             case 32: {
-              OptionalUint64 = input.ReadUInt64();
+              result.hasOptionalUint64 |= input.ReadUInt64(ref result.optionalUint64_);
               break;
             }
             case 40: {
-              OptionalSint32 = input.ReadSInt32();
+              result.hasOptionalSint32 |= input.ReadSInt32(ref result.optionalSint32_);
               break;
             }
             case 48: {
-              OptionalSint64 = input.ReadSInt64();
+              result.hasOptionalSint64 |= input.ReadSInt64(ref result.optionalSint64_);
               break;
             }
             case 61: {
-              OptionalFixed32 = input.ReadFixed32();
+              result.hasOptionalFixed32 |= input.ReadFixed32(ref result.optionalFixed32_);
               break;
             }
             case 65: {
-              OptionalFixed64 = input.ReadFixed64();
+              result.hasOptionalFixed64 |= input.ReadFixed64(ref result.optionalFixed64_);
               break;
             }
             case 77: {
-              OptionalSfixed32 = input.ReadSFixed32();
+              result.hasOptionalSfixed32 |= input.ReadSFixed32(ref result.optionalSfixed32_);
               break;
             }
             case 81: {
-              OptionalSfixed64 = input.ReadSFixed64();
+              result.hasOptionalSfixed64 |= input.ReadSFixed64(ref result.optionalSfixed64_);
               break;
             }
             case 93: {
-              OptionalFloat = input.ReadFloat();
+              result.hasOptionalFloat |= input.ReadFloat(ref result.optionalFloat_);
               break;
             }
             case 97: {
-              OptionalDouble = input.ReadDouble();
+              result.hasOptionalDouble |= input.ReadDouble(ref result.optionalDouble_);
               break;
             }
             case 104: {
-              OptionalBool = input.ReadBool();
+              result.hasOptionalBool |= input.ReadBool(ref result.optionalBool_);
               break;
             }
             case 114: {
-              OptionalString = input.ReadString();
+              result.hasOptionalString |= input.ReadString(ref result.optionalString_);
               break;
             }
             case 122: {
-              OptionalBytes = input.ReadBytes();
+              result.hasOptionalBytes |= input.ReadBytes(ref result.optionalBytes_);
               break;
             }
             case 131: {
@@ -3449,279 +3449,274 @@
               break;
             }
             case 168: {
-              int rawValue = input.ReadEnum();
-              if (!global::System.Enum.IsDefined(typeof(global::Google.ProtocolBuffers.TestProtos.TestAllTypes.Types.NestedEnum), rawValue)) {
+              object unknown;
+              if(input.ReadEnum(ref result.optionalNestedEnum_, out unknown)) {
+                result.hasOptionalNestedEnum = true;
+              } else if(unknown is int) {
                 if (unknownFields == null) {
                   unknownFields = pb::UnknownFieldSet.CreateBuilder(this.UnknownFields);
                 }
-                unknownFields.MergeVarintField(21, (ulong) rawValue);
-              } else {
-                OptionalNestedEnum = (global::Google.ProtocolBuffers.TestProtos.TestAllTypes.Types.NestedEnum) rawValue;
+                unknownFields.MergeVarintField(21, (ulong)(int)unknown);
               }
               break;
             }
             case 176: {
-              int rawValue = input.ReadEnum();
-              if (!global::System.Enum.IsDefined(typeof(global::Google.ProtocolBuffers.TestProtos.ForeignEnum), rawValue)) {
+              object unknown;
+              if(input.ReadEnum(ref result.optionalForeignEnum_, out unknown)) {
+                result.hasOptionalForeignEnum = true;
+              } else if(unknown is int) {
                 if (unknownFields == null) {
                   unknownFields = pb::UnknownFieldSet.CreateBuilder(this.UnknownFields);
                 }
-                unknownFields.MergeVarintField(22, (ulong) rawValue);
-              } else {
-                OptionalForeignEnum = (global::Google.ProtocolBuffers.TestProtos.ForeignEnum) rawValue;
+                unknownFields.MergeVarintField(22, (ulong)(int)unknown);
               }
               break;
             }
             case 184: {
-              int rawValue = input.ReadEnum();
-              if (!global::System.Enum.IsDefined(typeof(global::Google.ProtocolBuffers.TestProtos.ImportEnum), rawValue)) {
+              object unknown;
+              if(input.ReadEnum(ref result.optionalImportEnum_, out unknown)) {
+                result.hasOptionalImportEnum = true;
+              } else if(unknown is int) {
                 if (unknownFields == null) {
                   unknownFields = pb::UnknownFieldSet.CreateBuilder(this.UnknownFields);
                 }
-                unknownFields.MergeVarintField(23, (ulong) rawValue);
-              } else {
-                OptionalImportEnum = (global::Google.ProtocolBuffers.TestProtos.ImportEnum) rawValue;
+                unknownFields.MergeVarintField(23, (ulong)(int)unknown);
               }
               break;
             }
             case 194: {
-              OptionalStringPiece = input.ReadString();
+              result.hasOptionalStringPiece |= input.ReadString(ref result.optionalStringPiece_);
               break;
             }
             case 202: {
-              OptionalCord = input.ReadString();
+              result.hasOptionalCord |= input.ReadString(ref result.optionalCord_);
               break;
             }
             case 248: {
-              AddRepeatedInt32(input.ReadInt32());
+              input.ReadPrimitiveArray(pbd::FieldType.Int32, tag, field_name, result.repeatedInt32_);
               break;
             }
             case 256: {
-              AddRepeatedInt64(input.ReadInt64());
+              input.ReadPrimitiveArray(pbd::FieldType.Int64, tag, field_name, result.repeatedInt64_);
               break;
             }
             case 264: {
-              AddRepeatedUint32(input.ReadUInt32());
+              input.ReadPrimitiveArray(pbd::FieldType.UInt32, tag, field_name, result.repeatedUint32_);
               break;
             }
             case 272: {
-              AddRepeatedUint64(input.ReadUInt64());
+              input.ReadPrimitiveArray(pbd::FieldType.UInt64, tag, field_name, result.repeatedUint64_);
               break;
             }
             case 280: {
-              AddRepeatedSint32(input.ReadSInt32());
+              input.ReadPrimitiveArray(pbd::FieldType.SInt32, tag, field_name, result.repeatedSint32_);
               break;
             }
             case 288: {
-              AddRepeatedSint64(input.ReadSInt64());
+              input.ReadPrimitiveArray(pbd::FieldType.SInt64, tag, field_name, result.repeatedSint64_);
               break;
             }
             case 301: {
-              AddRepeatedFixed32(input.ReadFixed32());
+              input.ReadPrimitiveArray(pbd::FieldType.Fixed32, tag, field_name, result.repeatedFixed32_);
               break;
             }
             case 305: {
-              AddRepeatedFixed64(input.ReadFixed64());
+              input.ReadPrimitiveArray(pbd::FieldType.Fixed64, tag, field_name, result.repeatedFixed64_);
               break;
             }
             case 317: {
-              AddRepeatedSfixed32(input.ReadSFixed32());
+              input.ReadPrimitiveArray(pbd::FieldType.SFixed32, tag, field_name, result.repeatedSfixed32_);
               break;
             }
             case 321: {
-              AddRepeatedSfixed64(input.ReadSFixed64());
+              input.ReadPrimitiveArray(pbd::FieldType.SFixed64, tag, field_name, result.repeatedSfixed64_);
               break;
             }
             case 333: {
-              AddRepeatedFloat(input.ReadFloat());
+              input.ReadPrimitiveArray(pbd::FieldType.Float, tag, field_name, result.repeatedFloat_);
               break;
             }
             case 337: {
-              AddRepeatedDouble(input.ReadDouble());
+              input.ReadPrimitiveArray(pbd::FieldType.Double, tag, field_name, result.repeatedDouble_);
               break;
             }
             case 344: {
-              AddRepeatedBool(input.ReadBool());
+              input.ReadPrimitiveArray(pbd::FieldType.Bool, tag, field_name, result.repeatedBool_);
               break;
             }
             case 354: {
-              AddRepeatedString(input.ReadString());
+              input.ReadPrimitiveArray(pbd::FieldType.String, tag, field_name, result.repeatedString_);
               break;
             }
             case 362: {
-              AddRepeatedBytes(input.ReadBytes());
+              input.ReadPrimitiveArray(pbd::FieldType.Bytes, tag, field_name, result.repeatedBytes_);
               break;
             }
             case 371: {
-              global::Google.ProtocolBuffers.TestProtos.TestAllTypes.Types.RepeatedGroup.Builder subBuilder = global::Google.ProtocolBuffers.TestProtos.TestAllTypes.Types.RepeatedGroup.CreateBuilder();
-              input.ReadGroup(46, subBuilder, extensionRegistry);
-              AddRepeatedGroup(subBuilder.BuildPartial());
+              input.ReadGroupArray(tag, field_name, result.repeatedGroup_, global::Google.ProtocolBuffers.TestProtos.TestAllTypes.Types.RepeatedGroup.DefaultInstance, extensionRegistry);
               break;
             }
             case 386: {
-              global::Google.ProtocolBuffers.TestProtos.TestAllTypes.Types.NestedMessage.Builder subBuilder = global::Google.ProtocolBuffers.TestProtos.TestAllTypes.Types.NestedMessage.CreateBuilder();
-              input.ReadMessage(subBuilder, extensionRegistry);
-              AddRepeatedNestedMessage(subBuilder.BuildPartial());
+              input.ReadMessageArray(tag, field_name, result.repeatedNestedMessage_, global::Google.ProtocolBuffers.TestProtos.TestAllTypes.Types.NestedMessage.DefaultInstance, extensionRegistry);
               break;
             }
             case 394: {
-              global::Google.ProtocolBuffers.TestProtos.ForeignMessage.Builder subBuilder = global::Google.ProtocolBuffers.TestProtos.ForeignMessage.CreateBuilder();
-              input.ReadMessage(subBuilder, extensionRegistry);
-              AddRepeatedForeignMessage(subBuilder.BuildPartial());
+              input.ReadMessageArray(tag, field_name, result.repeatedForeignMessage_, global::Google.ProtocolBuffers.TestProtos.ForeignMessage.DefaultInstance, extensionRegistry);
               break;
             }
             case 402: {
-              global::Google.ProtocolBuffers.TestProtos.ImportMessage.Builder subBuilder = global::Google.ProtocolBuffers.TestProtos.ImportMessage.CreateBuilder();
-              input.ReadMessage(subBuilder, extensionRegistry);
-              AddRepeatedImportMessage(subBuilder.BuildPartial());
+              input.ReadMessageArray(tag, field_name, result.repeatedImportMessage_, global::Google.ProtocolBuffers.TestProtos.ImportMessage.DefaultInstance, extensionRegistry);
               break;
             }
             case 408: {
-              int rawValue = input.ReadEnum();
-              if (!global::System.Enum.IsDefined(typeof(global::Google.ProtocolBuffers.TestProtos.TestAllTypes.Types.NestedEnum), rawValue)) {
+              scg::ICollection<object> unknownItems;
+              input.ReadEnumArray<global::Google.ProtocolBuffers.TestProtos.TestAllTypes.Types.NestedEnum>(tag, field_name, result.repeatedNestedEnum_, out unknownItems);
+              if (unknownItems != null) {
                 if (unknownFields == null) {
                   unknownFields = pb::UnknownFieldSet.CreateBuilder(this.UnknownFields);
                 }
-                unknownFields.MergeVarintField(51, (ulong) rawValue);
-              } else {
-                AddRepeatedNestedEnum((global::Google.ProtocolBuffers.TestProtos.TestAllTypes.Types.NestedEnum) rawValue);
+                foreach (object rawValue in unknownItems)
+                  if (rawValue is int)
+                    unknownFields.MergeVarintField(51, (ulong)(int)rawValue);
               }
               break;
             }
             case 416: {
-              int rawValue = input.ReadEnum();
-              if (!global::System.Enum.IsDefined(typeof(global::Google.ProtocolBuffers.TestProtos.ForeignEnum), rawValue)) {
+              scg::ICollection<object> unknownItems;
+              input.ReadEnumArray<global::Google.ProtocolBuffers.TestProtos.ForeignEnum>(tag, field_name, result.repeatedForeignEnum_, out unknownItems);
+              if (unknownItems != null) {
                 if (unknownFields == null) {
                   unknownFields = pb::UnknownFieldSet.CreateBuilder(this.UnknownFields);
                 }
-                unknownFields.MergeVarintField(52, (ulong) rawValue);
-              } else {
-                AddRepeatedForeignEnum((global::Google.ProtocolBuffers.TestProtos.ForeignEnum) rawValue);
+                foreach (object rawValue in unknownItems)
+                  if (rawValue is int)
+                    unknownFields.MergeVarintField(52, (ulong)(int)rawValue);
               }
               break;
             }
             case 424: {
-              int rawValue = input.ReadEnum();
-              if (!global::System.Enum.IsDefined(typeof(global::Google.ProtocolBuffers.TestProtos.ImportEnum), rawValue)) {
+              scg::ICollection<object> unknownItems;
+              input.ReadEnumArray<global::Google.ProtocolBuffers.TestProtos.ImportEnum>(tag, field_name, result.repeatedImportEnum_, out unknownItems);
+              if (unknownItems != null) {
                 if (unknownFields == null) {
                   unknownFields = pb::UnknownFieldSet.CreateBuilder(this.UnknownFields);
                 }
-                unknownFields.MergeVarintField(53, (ulong) rawValue);
-              } else {
-                AddRepeatedImportEnum((global::Google.ProtocolBuffers.TestProtos.ImportEnum) rawValue);
+                foreach (object rawValue in unknownItems)
+                  if (rawValue is int)
+                    unknownFields.MergeVarintField(53, (ulong)(int)rawValue);
               }
               break;
             }
             case 434: {
-              AddRepeatedStringPiece(input.ReadString());
+              input.ReadPrimitiveArray(pbd::FieldType.String, tag, field_name, result.repeatedStringPiece_);
               break;
             }
             case 442: {
-              AddRepeatedCord(input.ReadString());
+              input.ReadPrimitiveArray(pbd::FieldType.String, tag, field_name, result.repeatedCord_);
               break;
             }
             case 488: {
-              DefaultInt32 = input.ReadInt32();
+              result.hasDefaultInt32 |= input.ReadInt32(ref result.defaultInt32_);
               break;
             }
             case 496: {
-              DefaultInt64 = input.ReadInt64();
+              result.hasDefaultInt64 |= input.ReadInt64(ref result.defaultInt64_);
               break;
             }
             case 504: {
-              DefaultUint32 = input.ReadUInt32();
+              result.hasDefaultUint32 |= input.ReadUInt32(ref result.defaultUint32_);
               break;
             }
             case 512: {
-              DefaultUint64 = input.ReadUInt64();
+              result.hasDefaultUint64 |= input.ReadUInt64(ref result.defaultUint64_);
               break;
             }
             case 520: {
-              DefaultSint32 = input.ReadSInt32();
+              result.hasDefaultSint32 |= input.ReadSInt32(ref result.defaultSint32_);
               break;
             }
             case 528: {
-              DefaultSint64 = input.ReadSInt64();
+              result.hasDefaultSint64 |= input.ReadSInt64(ref result.defaultSint64_);
               break;
             }
             case 541: {
-              DefaultFixed32 = input.ReadFixed32();
+              result.hasDefaultFixed32 |= input.ReadFixed32(ref result.defaultFixed32_);
               break;
             }
             case 545: {
-              DefaultFixed64 = input.ReadFixed64();
+              result.hasDefaultFixed64 |= input.ReadFixed64(ref result.defaultFixed64_);
               break;
             }
             case 557: {
-              DefaultSfixed32 = input.ReadSFixed32();
+              result.hasDefaultSfixed32 |= input.ReadSFixed32(ref result.defaultSfixed32_);
               break;
             }
             case 561: {
-              DefaultSfixed64 = input.ReadSFixed64();
+              result.hasDefaultSfixed64 |= input.ReadSFixed64(ref result.defaultSfixed64_);
               break;
             }
             case 573: {
-              DefaultFloat = input.ReadFloat();
+              result.hasDefaultFloat |= input.ReadFloat(ref result.defaultFloat_);
               break;
             }
             case 577: {
-              DefaultDouble = input.ReadDouble();
+              result.hasDefaultDouble |= input.ReadDouble(ref result.defaultDouble_);
               break;
             }
             case 584: {
-              DefaultBool = input.ReadBool();
+              result.hasDefaultBool |= input.ReadBool(ref result.defaultBool_);
               break;
             }
             case 594: {
-              DefaultString = input.ReadString();
+              result.hasDefaultString |= input.ReadString(ref result.defaultString_);
               break;
             }
             case 602: {
-              DefaultBytes = input.ReadBytes();
+              result.hasDefaultBytes |= input.ReadBytes(ref result.defaultBytes_);
               break;
             }
             case 648: {
-              int rawValue = input.ReadEnum();
-              if (!global::System.Enum.IsDefined(typeof(global::Google.ProtocolBuffers.TestProtos.TestAllTypes.Types.NestedEnum), rawValue)) {
+              object unknown;
+              if(input.ReadEnum(ref result.defaultNestedEnum_, out unknown)) {
+                result.hasDefaultNestedEnum = true;
+              } else if(unknown is int) {
                 if (unknownFields == null) {
                   unknownFields = pb::UnknownFieldSet.CreateBuilder(this.UnknownFields);
                 }
-                unknownFields.MergeVarintField(81, (ulong) rawValue);
-              } else {
-                DefaultNestedEnum = (global::Google.ProtocolBuffers.TestProtos.TestAllTypes.Types.NestedEnum) rawValue;
+                unknownFields.MergeVarintField(81, (ulong)(int)unknown);
               }
               break;
             }
             case 656: {
-              int rawValue = input.ReadEnum();
-              if (!global::System.Enum.IsDefined(typeof(global::Google.ProtocolBuffers.TestProtos.ForeignEnum), rawValue)) {
+              object unknown;
+              if(input.ReadEnum(ref result.defaultForeignEnum_, out unknown)) {
+                result.hasDefaultForeignEnum = true;
+              } else if(unknown is int) {
                 if (unknownFields == null) {
                   unknownFields = pb::UnknownFieldSet.CreateBuilder(this.UnknownFields);
                 }
-                unknownFields.MergeVarintField(82, (ulong) rawValue);
-              } else {
-                DefaultForeignEnum = (global::Google.ProtocolBuffers.TestProtos.ForeignEnum) rawValue;
+                unknownFields.MergeVarintField(82, (ulong)(int)unknown);
               }
               break;
             }
             case 664: {
-              int rawValue = input.ReadEnum();
-              if (!global::System.Enum.IsDefined(typeof(global::Google.ProtocolBuffers.TestProtos.ImportEnum), rawValue)) {
+              object unknown;
+              if(input.ReadEnum(ref result.defaultImportEnum_, out unknown)) {
+                result.hasDefaultImportEnum = true;
+              } else if(unknown is int) {
                 if (unknownFields == null) {
                   unknownFields = pb::UnknownFieldSet.CreateBuilder(this.UnknownFields);
                 }
-                unknownFields.MergeVarintField(83, (ulong) rawValue);
-              } else {
-                DefaultImportEnum = (global::Google.ProtocolBuffers.TestProtos.ImportEnum) rawValue;
+                unknownFields.MergeVarintField(83, (ulong)(int)unknown);
               }
               break;
             }
             case 674: {
-              DefaultStringPiece = input.ReadString();
+              result.hasDefaultStringPiece |= input.ReadString(ref result.defaultStringPiece_);
               break;
             }
             case 682: {
-              DefaultCord = input.ReadString();
+              result.hasDefaultCord |= input.ReadString(ref result.defaultCord_);
               break;
             }
           }
@@ -5511,11 +5506,11 @@
               if (unknownFields == null) {
                 unknownFields = pb::UnknownFieldSet.CreateBuilder(this.UnknownFields);
               }
-              ParseUnknownField(input, unknownFields, extensionRegistry, tag);
+              ParseUnknownField(input, unknownFields, extensionRegistry, tag, field_name);
               break;
             }
             case 8: {
-              DeprecatedInt32 = input.ReadInt32();
+              result.hasDeprecatedInt32 |= input.ReadInt32(ref result.deprecatedInt32_);
               break;
             }
           }
@@ -5735,11 +5730,11 @@
               if (unknownFields == null) {
                 unknownFields = pb::UnknownFieldSet.CreateBuilder(this.UnknownFields);
               }
-              ParseUnknownField(input, unknownFields, extensionRegistry, tag);
+              ParseUnknownField(input, unknownFields, extensionRegistry, tag, field_name);
               break;
             }
             case 8: {
-              C = input.ReadInt32();
+              result.hasC |= input.ReadInt32(ref result.c_);
               break;
             }
           }
@@ -5945,7 +5940,7 @@
               if (unknownFields == null) {
                 unknownFields = pb::UnknownFieldSet.CreateBuilder(this.UnknownFields);
               }
-              ParseUnknownField(input, unknownFields, extensionRegistry, tag);
+              ParseUnknownField(input, unknownFields, extensionRegistry, tag, field_name);
               break;
             }
           }
@@ -6147,11 +6142,11 @@
               if (unknownFields == null) {
                 unknownFields = pb::UnknownFieldSet.CreateBuilder(this.UnknownFields);
               }
-              ParseUnknownField(input, unknownFields, extensionRegistry, tag);
+              ParseUnknownField(input, unknownFields, extensionRegistry, tag, field_name);
               break;
             }
             case 136: {
-              A = input.ReadInt32();
+              result.hasA |= input.ReadInt32(ref result.a_);
               break;
             }
           }
@@ -6371,11 +6366,11 @@
               if (unknownFields == null) {
                 unknownFields = pb::UnknownFieldSet.CreateBuilder(this.UnknownFields);
               }
-              ParseUnknownField(input, unknownFields, extensionRegistry, tag);
+              ParseUnknownField(input, unknownFields, extensionRegistry, tag, field_name);
               break;
             }
             case 376: {
-              A = input.ReadInt32();
+              result.hasA |= input.ReadInt32(ref result.a_);
               break;
             }
           }
@@ -6578,7 +6573,7 @@
               if (unknownFields == null) {
                 unknownFields = pb::UnknownFieldSet.CreateBuilder(this.UnknownFields);
               }
-              ParseUnknownField(input, unknownFields, extensionRegistry, tag);
+              ParseUnknownField(input, unknownFields, extensionRegistry, tag, field_name);
               break;
             }
           }
@@ -7395,139 +7390,139 @@
               if (unknownFields == null) {
                 unknownFields = pb::UnknownFieldSet.CreateBuilder(this.UnknownFields);
               }
-              ParseUnknownField(input, unknownFields, extensionRegistry, tag);
+              ParseUnknownField(input, unknownFields, extensionRegistry, tag, field_name);
               break;
             }
             case 8: {
-              A = input.ReadInt32();
+              result.hasA |= input.ReadInt32(ref result.a_);
               break;
             }
             case 16: {
-              Dummy2 = input.ReadInt32();
+              result.hasDummy2 |= input.ReadInt32(ref result.dummy2_);
               break;
             }
             case 24: {
-              B = input.ReadInt32();
+              result.hasB |= input.ReadInt32(ref result.b_);
               break;
             }
             case 32: {
-              Dummy4 = input.ReadInt32();
+              result.hasDummy4 |= input.ReadInt32(ref result.dummy4_);
               break;
             }
             case 40: {
-              Dummy5 = input.ReadInt32();
+              result.hasDummy5 |= input.ReadInt32(ref result.dummy5_);
               break;
             }
             case 48: {
-              Dummy6 = input.ReadInt32();
+              result.hasDummy6 |= input.ReadInt32(ref result.dummy6_);
               break;
             }
             case 56: {
-              Dummy7 = input.ReadInt32();
+              result.hasDummy7 |= input.ReadInt32(ref result.dummy7_);
               break;
             }
             case 64: {
-              Dummy8 = input.ReadInt32();
+              result.hasDummy8 |= input.ReadInt32(ref result.dummy8_);
               break;
             }
             case 72: {
-              Dummy9 = input.ReadInt32();
+              result.hasDummy9 |= input.ReadInt32(ref result.dummy9_);
               break;
             }
             case 80: {
-              Dummy10 = input.ReadInt32();
+              result.hasDummy10 |= input.ReadInt32(ref result.dummy10_);
               break;
             }
             case 88: {
-              Dummy11 = input.ReadInt32();
+              result.hasDummy11 |= input.ReadInt32(ref result.dummy11_);
               break;
             }
             case 96: {
-              Dummy12 = input.ReadInt32();
+              result.hasDummy12 |= input.ReadInt32(ref result.dummy12_);
               break;
             }
             case 104: {
-              Dummy13 = input.ReadInt32();
+              result.hasDummy13 |= input.ReadInt32(ref result.dummy13_);
               break;
             }
             case 112: {
-              Dummy14 = input.ReadInt32();
+              result.hasDummy14 |= input.ReadInt32(ref result.dummy14_);
               break;
             }
             case 120: {
-              Dummy15 = input.ReadInt32();
+              result.hasDummy15 |= input.ReadInt32(ref result.dummy15_);
               break;
             }
             case 128: {
-              Dummy16 = input.ReadInt32();
+              result.hasDummy16 |= input.ReadInt32(ref result.dummy16_);
               break;
             }
             case 136: {
-              Dummy17 = input.ReadInt32();
+              result.hasDummy17 |= input.ReadInt32(ref result.dummy17_);
               break;
             }
             case 144: {
-              Dummy18 = input.ReadInt32();
+              result.hasDummy18 |= input.ReadInt32(ref result.dummy18_);
               break;
             }
             case 152: {
-              Dummy19 = input.ReadInt32();
+              result.hasDummy19 |= input.ReadInt32(ref result.dummy19_);
               break;
             }
             case 160: {
-              Dummy20 = input.ReadInt32();
+              result.hasDummy20 |= input.ReadInt32(ref result.dummy20_);
               break;
             }
             case 168: {
-              Dummy21 = input.ReadInt32();
+              result.hasDummy21 |= input.ReadInt32(ref result.dummy21_);
               break;
             }
             case 176: {
-              Dummy22 = input.ReadInt32();
+              result.hasDummy22 |= input.ReadInt32(ref result.dummy22_);
               break;
             }
             case 184: {
-              Dummy23 = input.ReadInt32();
+              result.hasDummy23 |= input.ReadInt32(ref result.dummy23_);
               break;
             }
             case 192: {
-              Dummy24 = input.ReadInt32();
+              result.hasDummy24 |= input.ReadInt32(ref result.dummy24_);
               break;
             }
             case 200: {
-              Dummy25 = input.ReadInt32();
+              result.hasDummy25 |= input.ReadInt32(ref result.dummy25_);
               break;
             }
             case 208: {
-              Dummy26 = input.ReadInt32();
+              result.hasDummy26 |= input.ReadInt32(ref result.dummy26_);
               break;
             }
             case 216: {
-              Dummy27 = input.ReadInt32();
+              result.hasDummy27 |= input.ReadInt32(ref result.dummy27_);
               break;
             }
             case 224: {
-              Dummy28 = input.ReadInt32();
+              result.hasDummy28 |= input.ReadInt32(ref result.dummy28_);
               break;
             }
             case 232: {
-              Dummy29 = input.ReadInt32();
+              result.hasDummy29 |= input.ReadInt32(ref result.dummy29_);
               break;
             }
             case 240: {
-              Dummy30 = input.ReadInt32();
+              result.hasDummy30 |= input.ReadInt32(ref result.dummy30_);
               break;
             }
             case 248: {
-              Dummy31 = input.ReadInt32();
+              result.hasDummy31 |= input.ReadInt32(ref result.dummy31_);
               break;
             }
             case 256: {
-              Dummy32 = input.ReadInt32();
+              result.hasDummy32 |= input.ReadInt32(ref result.dummy32_);
               break;
             }
             case 264: {
-              C = input.ReadInt32();
+              result.hasC |= input.ReadInt32(ref result.c_);
               break;
             }
           }
@@ -8370,7 +8365,7 @@
               if (unknownFields == null) {
                 unknownFields = pb::UnknownFieldSet.CreateBuilder(this.UnknownFields);
               }
-              ParseUnknownField(input, unknownFields, extensionRegistry, tag);
+              ParseUnknownField(input, unknownFields, extensionRegistry, tag, field_name);
               break;
             }
             case 10: {
@@ -8383,13 +8378,11 @@
               break;
             }
             case 18: {
-              global::Google.ProtocolBuffers.TestProtos.TestRequired.Builder subBuilder = global::Google.ProtocolBuffers.TestProtos.TestRequired.CreateBuilder();
-              input.ReadMessage(subBuilder, extensionRegistry);
-              AddRepeatedMessage(subBuilder.BuildPartial());
+              input.ReadMessageArray(tag, field_name, result.repeatedMessage_, global::Google.ProtocolBuffers.TestProtos.TestRequired.DefaultInstance, extensionRegistry);
               break;
             }
             case 24: {
-              Dummy = input.ReadInt32();
+              result.hasDummy |= input.ReadInt32(ref result.dummy_);
               break;
             }
           }
@@ -8683,7 +8676,7 @@
               if (unknownFields == null) {
                 unknownFields = pb::UnknownFieldSet.CreateBuilder(this.UnknownFields);
               }
-              ParseUnknownField(input, unknownFields, extensionRegistry, tag);
+              ParseUnknownField(input, unknownFields, extensionRegistry, tag, field_name);
               break;
             }
             case 10: {
@@ -8911,7 +8904,7 @@
               if (unknownFields == null) {
                 unknownFields = pb::UnknownFieldSet.CreateBuilder(this.UnknownFields);
               }
-              ParseUnknownField(input, unknownFields, extensionRegistry, tag);
+              ParseUnknownField(input, unknownFields, extensionRegistry, tag, field_name);
               break;
             }
           }
@@ -9099,7 +9092,7 @@
               if (unknownFields == null) {
                 unknownFields = pb::UnknownFieldSet.CreateBuilder(this.UnknownFields);
               }
-              ParseUnknownField(input, unknownFields, extensionRegistry, tag);
+              ParseUnknownField(input, unknownFields, extensionRegistry, tag, field_name);
               break;
             }
           }
@@ -9289,7 +9282,7 @@
               if (unknownFields == null) {
                 unknownFields = pb::UnknownFieldSet.CreateBuilder(this.UnknownFields);
               }
-              ParseUnknownField(input, unknownFields, extensionRegistry, tag);
+              ParseUnknownField(input, unknownFields, extensionRegistry, tag, field_name);
               break;
             }
           }
@@ -9510,15 +9503,15 @@
               if (unknownFields == null) {
                 unknownFields = pb::UnknownFieldSet.CreateBuilder(this.UnknownFields);
               }
-              ParseUnknownField(input, unknownFields, extensionRegistry, tag);
+              ParseUnknownField(input, unknownFields, extensionRegistry, tag, field_name);
               break;
             }
             case 8: {
-              A = input.ReadInt32();
+              result.hasA |= input.ReadInt32(ref result.a_);
               break;
             }
             case 2147483640: {
-              Bb = input.ReadInt32();
+              result.hasBb |= input.ReadInt32(ref result.bb_);
               break;
             }
           }
@@ -9775,7 +9768,7 @@
               if (unknownFields == null) {
                 unknownFields = pb::UnknownFieldSet.CreateBuilder(this.UnknownFields);
               }
-              ParseUnknownField(input, unknownFields, extensionRegistry, tag);
+              ParseUnknownField(input, unknownFields, extensionRegistry, tag, field_name);
               break;
             }
             case 10: {
@@ -9788,7 +9781,7 @@
               break;
             }
             case 16: {
-              I = input.ReadInt32();
+              result.hasI |= input.ReadInt32(ref result.i_);
               break;
             }
           }
@@ -10044,7 +10037,7 @@
               if (unknownFields == null) {
                 unknownFields = pb::UnknownFieldSet.CreateBuilder(this.UnknownFields);
               }
-              ParseUnknownField(input, unknownFields, extensionRegistry, tag);
+              ParseUnknownField(input, unknownFields, extensionRegistry, tag, field_name);
               break;
             }
             case 10: {
@@ -10310,7 +10303,7 @@
               if (unknownFields == null) {
                 unknownFields = pb::UnknownFieldSet.CreateBuilder(this.UnknownFields);
               }
-              ParseUnknownField(input, unknownFields, extensionRegistry, tag);
+              ParseUnknownField(input, unknownFields, extensionRegistry, tag, field_name);
               break;
             }
             case 10: {
@@ -10323,7 +10316,7 @@
               break;
             }
             case 16: {
-              OptionalInt32 = input.ReadInt32();
+              result.hasOptionalInt32 |= input.ReadInt32(ref result.optionalInt32_);
               break;
             }
           }
@@ -10609,11 +10602,11 @@
                   if (unknownFields == null) {
                     unknownFields = pb::UnknownFieldSet.CreateBuilder(this.UnknownFields);
                   }
-                  ParseUnknownField(input, unknownFields, extensionRegistry, tag);
+                  ParseUnknownField(input, unknownFields, extensionRegistry, tag, field_name);
                   break;
                 }
                 case 8: {
-                  A = input.ReadInt32();
+                  result.hasA |= input.ReadInt32(ref result.a_);
                   break;
                 }
               }
@@ -10833,11 +10826,11 @@
                   if (unknownFields == null) {
                     unknownFields = pb::UnknownFieldSet.CreateBuilder(this.UnknownFields);
                   }
-                  ParseUnknownField(input, unknownFields, extensionRegistry, tag);
+                  ParseUnknownField(input, unknownFields, extensionRegistry, tag, field_name);
                   break;
                 }
                 case 8: {
-                  A = input.ReadInt32();
+                  result.hasA |= input.ReadInt32(ref result.a_);
                   break;
                 }
               }
@@ -11073,11 +11066,11 @@
               if (unknownFields == null) {
                 unknownFields = pb::UnknownFieldSet.CreateBuilder(this.UnknownFields);
               }
-              ParseUnknownField(input, unknownFields, extensionRegistry, tag);
+              ParseUnknownField(input, unknownFields, extensionRegistry, tag, field_name);
               break;
             }
             case 8: {
-              A = input.ReadInt32();
+              result.hasA |= input.ReadInt32(ref result.a_);
               break;
             }
             case 19: {
@@ -11447,17 +11440,15 @@
                   if (unknownFields == null) {
                     unknownFields = pb::UnknownFieldSet.CreateBuilder(this.UnknownFields);
                   }
-                  ParseUnknownField(input, unknownFields, extensionRegistry, tag);
+                  ParseUnknownField(input, unknownFields, extensionRegistry, tag, field_name);
                   break;
                 }
                 case 8: {
-                  AddNestedmessageRepeatedInt32(input.ReadInt32());
+                  input.ReadPrimitiveArray(pbd::FieldType.Int32, tag, field_name, result.nestedmessageRepeatedInt32_);
                   break;
                 }
                 case 18: {
-                  global::Google.ProtocolBuffers.TestProtos.ForeignMessage.Builder subBuilder = global::Google.ProtocolBuffers.TestProtos.ForeignMessage.CreateBuilder();
-                  input.ReadMessage(subBuilder, extensionRegistry);
-                  AddNestedmessageRepeatedForeignmessage(subBuilder.BuildPartial());
+                  input.ReadMessageArray(tag, field_name, result.nestedmessageRepeatedForeignmessage_, global::Google.ProtocolBuffers.TestProtos.ForeignMessage.DefaultInstance, extensionRegistry);
                   break;
                 }
               }
@@ -11701,7 +11692,7 @@
               if (unknownFields == null) {
                 unknownFields = pb::UnknownFieldSet.CreateBuilder(this.UnknownFields);
               }
-              ParseUnknownField(input, unknownFields, extensionRegistry, tag);
+              ParseUnknownField(input, unknownFields, extensionRegistry, tag, field_name);
               break;
             }
             case 10: {
@@ -12202,26 +12193,26 @@
               if (unknownFields == null) {
                 unknownFields = pb::UnknownFieldSet.CreateBuilder(this.UnknownFields);
               }
-              ParseUnknownField(input, unknownFields, extensionRegistry, tag);
+              ParseUnknownField(input, unknownFields, extensionRegistry, tag, field_name);
               break;
             }
             case 8: {
-              PrimitiveField = input.ReadInt32();
+              result.hasPrimitiveField |= input.ReadInt32(ref result.primitiveField_);
               break;
             }
             case 18: {
-              StringField = input.ReadString();
+              result.hasStringField |= input.ReadString(ref result.stringField_);
               break;
             }
             case 24: {
-              int rawValue = input.ReadEnum();
-              if (!global::System.Enum.IsDefined(typeof(global::Google.ProtocolBuffers.TestProtos.ForeignEnum), rawValue)) {
+              object unknown;
+              if(input.ReadEnum(ref result.enumField_, out unknown)) {
+                result.hasEnumField = true;
+              } else if(unknown is int) {
                 if (unknownFields == null) {
                   unknownFields = pb::UnknownFieldSet.CreateBuilder(this.UnknownFields);
                 }
-                unknownFields.MergeVarintField(3, (ulong) rawValue);
-              } else {
-                EnumField = (global::Google.ProtocolBuffers.TestProtos.ForeignEnum) rawValue;
+                unknownFields.MergeVarintField(3, (ulong)(int)unknown);
               }
               break;
             }
@@ -12235,45 +12226,44 @@
               break;
             }
             case 42: {
-              StringPieceField = input.ReadString();
+              result.hasStringPieceField |= input.ReadString(ref result.stringPieceField_);
               break;
             }
             case 50: {
-              CordField = input.ReadString();
+              result.hasCordField |= input.ReadString(ref result.cordField_);
               break;
             }
             case 56: {
-              AddRepeatedPrimitiveField(input.ReadInt32());
+              input.ReadPrimitiveArray(pbd::FieldType.Int32, tag, field_name, result.repeatedPrimitiveField_);
               break;
             }
             case 66: {
-              AddRepeatedStringField(input.ReadString());
+              input.ReadPrimitiveArray(pbd::FieldType.String, tag, field_name, result.repeatedStringField_);
               break;
             }
             case 72: {
-              int rawValue = input.ReadEnum();
-              if (!global::System.Enum.IsDefined(typeof(global::Google.ProtocolBuffers.TestProtos.ForeignEnum), rawValue)) {
+              scg::ICollection<object> unknownItems;
+              input.ReadEnumArray<global::Google.ProtocolBuffers.TestProtos.ForeignEnum>(tag, field_name, result.repeatedEnumField_, out unknownItems);
+              if (unknownItems != null) {
                 if (unknownFields == null) {
                   unknownFields = pb::UnknownFieldSet.CreateBuilder(this.UnknownFields);
                 }
-                unknownFields.MergeVarintField(9, (ulong) rawValue);
-              } else {
-                AddRepeatedEnumField((global::Google.ProtocolBuffers.TestProtos.ForeignEnum) rawValue);
+                foreach (object rawValue in unknownItems)
+                  if (rawValue is int)
+                    unknownFields.MergeVarintField(9, (ulong)(int)rawValue);
               }
               break;
             }
             case 82: {
-              global::Google.ProtocolBuffers.TestProtos.ForeignMessage.Builder subBuilder = global::Google.ProtocolBuffers.TestProtos.ForeignMessage.CreateBuilder();
-              input.ReadMessage(subBuilder, extensionRegistry);
-              AddRepeatedMessageField(subBuilder.BuildPartial());
+              input.ReadMessageArray(tag, field_name, result.repeatedMessageField_, global::Google.ProtocolBuffers.TestProtos.ForeignMessage.DefaultInstance, extensionRegistry);
               break;
             }
             case 90: {
-              AddRepeatedStringPieceField(input.ReadString());
+              input.ReadPrimitiveArray(pbd::FieldType.String, tag, field_name, result.repeatedStringPieceField_);
               break;
             }
             case 98: {
-              AddRepeatedCordField(input.ReadString());
+              input.ReadPrimitiveArray(pbd::FieldType.String, tag, field_name, result.repeatedCordField_);
               break;
             }
           }
@@ -12822,19 +12812,19 @@
               if (unknownFields == null) {
                 unknownFields = pb::UnknownFieldSet.CreateBuilder(this.UnknownFields);
               }
-              ParseUnknownField(input, unknownFields, extensionRegistry, tag);
+              ParseUnknownField(input, unknownFields, extensionRegistry, tag, field_name);
               break;
             }
             case 8: {
-              MyInt = input.ReadInt64();
+              result.hasMyInt |= input.ReadInt64(ref result.myInt_);
               break;
             }
             case 90: {
-              MyString = input.ReadString();
+              result.hasMyString |= input.ReadString(ref result.myString_);
               break;
             }
             case 813: {
-              MyFloat = input.ReadFloat();
+              result.hasMyFloat |= input.ReadFloat(ref result.myFloat_);
               break;
             }
           }
@@ -13435,83 +13425,83 @@
               if (unknownFields == null) {
                 unknownFields = pb::UnknownFieldSet.CreateBuilder(this.UnknownFields);
               }
-              ParseUnknownField(input, unknownFields, extensionRegistry, tag);
+              ParseUnknownField(input, unknownFields, extensionRegistry, tag, field_name);
               break;
             }
             case 10: {
-              EscapedBytes = input.ReadBytes();
+              result.hasEscapedBytes |= input.ReadBytes(ref result.escapedBytes_);
               break;
             }
             case 16: {
-              LargeUint32 = input.ReadUInt32();
+              result.hasLargeUint32 |= input.ReadUInt32(ref result.largeUint32_);
               break;
             }
             case 24: {
-              LargeUint64 = input.ReadUInt64();
+              result.hasLargeUint64 |= input.ReadUInt64(ref result.largeUint64_);
               break;
             }
             case 32: {
-              SmallInt32 = input.ReadInt32();
+              result.hasSmallInt32 |= input.ReadInt32(ref result.smallInt32_);
               break;
             }
             case 40: {
-              SmallInt64 = input.ReadInt64();
+              result.hasSmallInt64 |= input.ReadInt64(ref result.smallInt64_);
               break;
             }
             case 50: {
-              Utf8String = input.ReadString();
+              result.hasUtf8String |= input.ReadString(ref result.utf8String_);
               break;
             }
             case 61: {
-              ZeroFloat = input.ReadFloat();
+              result.hasZeroFloat |= input.ReadFloat(ref result.zeroFloat_);
               break;
             }
             case 69: {
-              OneFloat = input.ReadFloat();
+              result.hasOneFloat |= input.ReadFloat(ref result.oneFloat_);
               break;
             }
             case 77: {
-              SmallFloat = input.ReadFloat();
+              result.hasSmallFloat |= input.ReadFloat(ref result.smallFloat_);
               break;
             }
             case 85: {
-              NegativeOneFloat = input.ReadFloat();
+              result.hasNegativeOneFloat |= input.ReadFloat(ref result.negativeOneFloat_);
               break;
             }
             case 93: {
-              NegativeFloat = input.ReadFloat();
+              result.hasNegativeFloat |= input.ReadFloat(ref result.negativeFloat_);
               break;
             }
             case 101: {
-              LargeFloat = input.ReadFloat();
+              result.hasLargeFloat |= input.ReadFloat(ref result.largeFloat_);
               break;
             }
             case 109: {
-              SmallNegativeFloat = input.ReadFloat();
+              result.hasSmallNegativeFloat |= input.ReadFloat(ref result.smallNegativeFloat_);
               break;
             }
             case 113: {
-              InfDouble = input.ReadDouble();
+              result.hasInfDouble |= input.ReadDouble(ref result.infDouble_);
               break;
             }
             case 121: {
-              NegInfDouble = input.ReadDouble();
+              result.hasNegInfDouble |= input.ReadDouble(ref result.negInfDouble_);
               break;
             }
             case 129: {
-              NanDouble = input.ReadDouble();
+              result.hasNanDouble |= input.ReadDouble(ref result.nanDouble_);
               break;
             }
             case 141: {
-              InfFloat = input.ReadFloat();
+              result.hasInfFloat |= input.ReadFloat(ref result.infFloat_);
               break;
             }
             case 149: {
-              NegInfFloat = input.ReadFloat();
+              result.hasNegInfFloat |= input.ReadFloat(ref result.negInfFloat_);
               break;
             }
             case 157: {
-              NanFloat = input.ReadFloat();
+              result.hasNanFloat |= input.ReadFloat(ref result.nanFloat_);
               break;
             }
           }
@@ -14061,11 +14051,11 @@
               if (unknownFields == null) {
                 unknownFields = pb::UnknownFieldSet.CreateBuilder(this.UnknownFields);
               }
-              ParseUnknownField(input, unknownFields, extensionRegistry, tag);
+              ParseUnknownField(input, unknownFields, extensionRegistry, tag, field_name);
               break;
             }
             case 10: {
-              Data = input.ReadString();
+              result.hasData |= input.ReadString(ref result.data_);
               break;
             }
           }
@@ -14286,11 +14276,11 @@
               if (unknownFields == null) {
                 unknownFields = pb::UnknownFieldSet.CreateBuilder(this.UnknownFields);
               }
-              ParseUnknownField(input, unknownFields, extensionRegistry, tag);
+              ParseUnknownField(input, unknownFields, extensionRegistry, tag, field_name);
               break;
             }
             case 10: {
-              Data = input.ReadBytes();
+              result.hasData |= input.ReadBytes(ref result.data_);
               break;
             }
           }
@@ -14921,141 +14911,72 @@
               if (unknownFields == null) {
                 unknownFields = pb::UnknownFieldSet.CreateBuilder(this.UnknownFields);
               }
-              ParseUnknownField(input, unknownFields, extensionRegistry, tag);
+              ParseUnknownField(input, unknownFields, extensionRegistry, tag, field_name);
               break;
             }
             case 722: {
-              int length = input.ReadInt32();
-              int limit = input.PushLimit(length);
-              while (!input.ReachedLimit) {
-                AddPackedInt32(input.ReadInt32());
-              }
-              input.PopLimit(limit);
+              input.ReadPrimitiveArray(pbd::FieldType.Int32, tag, field_name, result.packedInt32_);
               break;
             }
             case 730: {
-              int length = input.ReadInt32();
-              int limit = input.PushLimit(length);
-              while (!input.ReachedLimit) {
-                AddPackedInt64(input.ReadInt64());
-              }
-              input.PopLimit(limit);
+              input.ReadPrimitiveArray(pbd::FieldType.Int64, tag, field_name, result.packedInt64_);
               break;
             }
             case 738: {
-              int length = input.ReadInt32();
-              int limit = input.PushLimit(length);
-              while (!input.ReachedLimit) {
-                AddPackedUint32(input.ReadUInt32());
-              }
-              input.PopLimit(limit);
+              input.ReadPrimitiveArray(pbd::FieldType.UInt32, tag, field_name, result.packedUint32_);
               break;
             }
             case 746: {
-              int length = input.ReadInt32();
-              int limit = input.PushLimit(length);
-              while (!input.ReachedLimit) {
-                AddPackedUint64(input.ReadUInt64());
-              }
-              input.PopLimit(limit);
+              input.ReadPrimitiveArray(pbd::FieldType.UInt64, tag, field_name, result.packedUint64_);
               break;
             }
             case 754: {
-              int length = input.ReadInt32();
-              int limit = input.PushLimit(length);
-              while (!input.ReachedLimit) {
-                AddPackedSint32(input.ReadSInt32());
-              }
-              input.PopLimit(limit);
+              input.ReadPrimitiveArray(pbd::FieldType.SInt32, tag, field_name, result.packedSint32_);
               break;
             }
             case 762: {
-              int length = input.ReadInt32();
-              int limit = input.PushLimit(length);
-              while (!input.ReachedLimit) {
-                AddPackedSint64(input.ReadSInt64());
-              }
-              input.PopLimit(limit);
+              input.ReadPrimitiveArray(pbd::FieldType.SInt64, tag, field_name, result.packedSint64_);
               break;
             }
             case 770: {
-              int length = input.ReadInt32();
-              int limit = input.PushLimit(length);
-              while (!input.ReachedLimit) {
-                AddPackedFixed32(input.ReadFixed32());
-              }
-              input.PopLimit(limit);
+              input.ReadPrimitiveArray(pbd::FieldType.Fixed32, tag, field_name, result.packedFixed32_);
               break;
             }
             case 778: {
-              int length = input.ReadInt32();
-              int limit = input.PushLimit(length);
-              while (!input.ReachedLimit) {
-                AddPackedFixed64(input.ReadFixed64());
-              }
-              input.PopLimit(limit);
+              input.ReadPrimitiveArray(pbd::FieldType.Fixed64, tag, field_name, result.packedFixed64_);
               break;
             }
             case 786: {
-              int length = input.ReadInt32();
-              int limit = input.PushLimit(length);
-              while (!input.ReachedLimit) {
-                AddPackedSfixed32(input.ReadSFixed32());
-              }
-              input.PopLimit(limit);
+              input.ReadPrimitiveArray(pbd::FieldType.SFixed32, tag, field_name, result.packedSfixed32_);
               break;
             }
             case 794: {
-              int length = input.ReadInt32();
-              int limit = input.PushLimit(length);
-              while (!input.ReachedLimit) {
-                AddPackedSfixed64(input.ReadSFixed64());
-              }
-              input.PopLimit(limit);
+              input.ReadPrimitiveArray(pbd::FieldType.SFixed64, tag, field_name, result.packedSfixed64_);
               break;
             }
             case 802: {
-              int length = input.ReadInt32();
-              int limit = input.PushLimit(length);
-              while (!input.ReachedLimit) {
-                AddPackedFloat(input.ReadFloat());
-              }
-              input.PopLimit(limit);
+              input.ReadPrimitiveArray(pbd::FieldType.Float, tag, field_name, result.packedFloat_);
               break;
             }
             case 810: {
-              int length = input.ReadInt32();
-              int limit = input.PushLimit(length);
-              while (!input.ReachedLimit) {
-                AddPackedDouble(input.ReadDouble());
-              }
-              input.PopLimit(limit);
+              input.ReadPrimitiveArray(pbd::FieldType.Double, tag, field_name, result.packedDouble_);
               break;
             }
             case 818: {
-              int length = input.ReadInt32();
-              int limit = input.PushLimit(length);
-              while (!input.ReachedLimit) {
-                AddPackedBool(input.ReadBool());
-              }
-              input.PopLimit(limit);
+              input.ReadPrimitiveArray(pbd::FieldType.Bool, tag, field_name, result.packedBool_);
               break;
             }
             case 826: {
-              int length = input.ReadInt32();
-              int oldLimit = input.PushLimit(length);
-              while (!input.ReachedLimit) {
-                int rawValue = input.ReadEnum();
-                if (!global::System.Enum.IsDefined(typeof(global::Google.ProtocolBuffers.TestProtos.ForeignEnum), rawValue)) {
-                  if (unknownFields == null) {
-                    unknownFields = pb::UnknownFieldSet.CreateBuilder(this.UnknownFields);
-                  }
-                  unknownFields.MergeVarintField(103, (ulong) rawValue);
-                } else {
-                  AddPackedEnum((global::Google.ProtocolBuffers.TestProtos.ForeignEnum) rawValue);
+              scg::ICollection<object> unknownItems;
+              input.ReadEnumArray<global::Google.ProtocolBuffers.TestProtos.ForeignEnum>(tag, field_name, result.packedEnum_, out unknownItems);
+              if (unknownItems != null) {
+                if (unknownFields == null) {
+                  unknownFields = pb::UnknownFieldSet.CreateBuilder(this.UnknownFields);
                 }
+                foreach (object rawValue in unknownItems)
+                  if (rawValue is int)
+                    unknownFields.MergeVarintField(103, (ulong)(int)rawValue);
               }
-              input.PopLimit(oldLimit);
               break;
             }
           }
@@ -15996,70 +15917,71 @@
               if (unknownFields == null) {
                 unknownFields = pb::UnknownFieldSet.CreateBuilder(this.UnknownFields);
               }
-              ParseUnknownField(input, unknownFields, extensionRegistry, tag);
+              ParseUnknownField(input, unknownFields, extensionRegistry, tag, field_name);
               break;
             }
             case 720: {
-              AddUnpackedInt32(input.ReadInt32());
+              input.ReadPrimitiveArray(pbd::FieldType.Int32, tag, field_name, result.unpackedInt32_);
               break;
             }
             case 728: {
-              AddUnpackedInt64(input.ReadInt64());
+              input.ReadPrimitiveArray(pbd::FieldType.Int64, tag, field_name, result.unpackedInt64_);
               break;
             }
             case 736: {
-              AddUnpackedUint32(input.ReadUInt32());
+              input.ReadPrimitiveArray(pbd::FieldType.UInt32, tag, field_name, result.unpackedUint32_);
               break;
             }
             case 744: {
-              AddUnpackedUint64(input.ReadUInt64());
+              input.ReadPrimitiveArray(pbd::FieldType.UInt64, tag, field_name, result.unpackedUint64_);
               break;
             }
             case 752: {
-              AddUnpackedSint32(input.ReadSInt32());
+              input.ReadPrimitiveArray(pbd::FieldType.SInt32, tag, field_name, result.unpackedSint32_);
               break;
             }
             case 760: {
-              AddUnpackedSint64(input.ReadSInt64());
+              input.ReadPrimitiveArray(pbd::FieldType.SInt64, tag, field_name, result.unpackedSint64_);
               break;
             }
             case 773: {
-              AddUnpackedFixed32(input.ReadFixed32());
+              input.ReadPrimitiveArray(pbd::FieldType.Fixed32, tag, field_name, result.unpackedFixed32_);
               break;
             }
             case 777: {
-              AddUnpackedFixed64(input.ReadFixed64());
+              input.ReadPrimitiveArray(pbd::FieldType.Fixed64, tag, field_name, result.unpackedFixed64_);
               break;
             }
             case 789: {
-              AddUnpackedSfixed32(input.ReadSFixed32());
+              input.ReadPrimitiveArray(pbd::FieldType.SFixed32, tag, field_name, result.unpackedSfixed32_);
               break;
             }
             case 793: {
-              AddUnpackedSfixed64(input.ReadSFixed64());
+              input.ReadPrimitiveArray(pbd::FieldType.SFixed64, tag, field_name, result.unpackedSfixed64_);
               break;
             }
             case 805: {
-              AddUnpackedFloat(input.ReadFloat());
+              input.ReadPrimitiveArray(pbd::FieldType.Float, tag, field_name, result.unpackedFloat_);
               break;
             }
             case 809: {
-              AddUnpackedDouble(input.ReadDouble());
+              input.ReadPrimitiveArray(pbd::FieldType.Double, tag, field_name, result.unpackedDouble_);
               break;
             }
             case 816: {
-              AddUnpackedBool(input.ReadBool());
+              input.ReadPrimitiveArray(pbd::FieldType.Bool, tag, field_name, result.unpackedBool_);
               break;
             }
             case 824: {
-              int rawValue = input.ReadEnum();
-              if (!global::System.Enum.IsDefined(typeof(global::Google.ProtocolBuffers.TestProtos.ForeignEnum), rawValue)) {
+              scg::ICollection<object> unknownItems;
+              input.ReadEnumArray<global::Google.ProtocolBuffers.TestProtos.ForeignEnum>(tag, field_name, result.unpackedEnum_, out unknownItems);
+              if (unknownItems != null) {
                 if (unknownFields == null) {
                   unknownFields = pb::UnknownFieldSet.CreateBuilder(this.UnknownFields);
                 }
-                unknownFields.MergeVarintField(103, (ulong) rawValue);
-              } else {
-                AddUnpackedEnum((global::Google.ProtocolBuffers.TestProtos.ForeignEnum) rawValue);
+                foreach (object rawValue in unknownItems)
+                  if (rawValue is int)
+                    unknownFields.MergeVarintField(103, (ulong)(int)rawValue);
               }
               break;
             }
@@ -16632,7 +16554,7 @@
               if (unknownFields == null) {
                 unknownFields = pb::UnknownFieldSet.CreateBuilder(this.UnknownFields);
               }
-              ParseUnknownField(input, unknownFields, extensionRegistry, tag);
+              ParseUnknownField(input, unknownFields, extensionRegistry, tag, field_name);
               break;
             }
           }
@@ -16872,11 +16794,11 @@
                   if (unknownFields == null) {
                     unknownFields = pb::UnknownFieldSet.CreateBuilder(this.UnknownFields);
                   }
-                  ParseUnknownField(input, unknownFields, extensionRegistry, tag);
+                  ParseUnknownField(input, unknownFields, extensionRegistry, tag, field_name);
                   break;
                 }
                 case 16800: {
-                  DynamicField = input.ReadInt32();
+                  result.hasDynamicField |= input.ReadInt32(ref result.dynamicField_);
                   break;
                 }
               }
@@ -17209,34 +17131,34 @@
               if (unknownFields == null) {
                 unknownFields = pb::UnknownFieldSet.CreateBuilder(this.UnknownFields);
               }
-              ParseUnknownField(input, unknownFields, extensionRegistry, tag);
+              ParseUnknownField(input, unknownFields, extensionRegistry, tag, field_name);
               break;
             }
             case 16005: {
-              ScalarExtension = input.ReadFixed32();
+              result.hasScalarExtension |= input.ReadFixed32(ref result.scalarExtension_);
               break;
             }
             case 16008: {
-              int rawValue = input.ReadEnum();
-              if (!global::System.Enum.IsDefined(typeof(global::Google.ProtocolBuffers.TestProtos.ForeignEnum), rawValue)) {
+              object unknown;
+              if(input.ReadEnum(ref result.enumExtension_, out unknown)) {
+                result.hasEnumExtension = true;
+              } else if(unknown is int) {
                 if (unknownFields == null) {
                   unknownFields = pb::UnknownFieldSet.CreateBuilder(this.UnknownFields);
                 }
-                unknownFields.MergeVarintField(2001, (ulong) rawValue);
-              } else {
-                EnumExtension = (global::Google.ProtocolBuffers.TestProtos.ForeignEnum) rawValue;
+                unknownFields.MergeVarintField(2001, (ulong)(int)unknown);
               }
               break;
             }
             case 16016: {
-              int rawValue = input.ReadEnum();
-              if (!global::System.Enum.IsDefined(typeof(global::Google.ProtocolBuffers.TestProtos.TestDynamicExtensions.Types.DynamicEnumType), rawValue)) {
+              object unknown;
+              if(input.ReadEnum(ref result.dynamicEnumExtension_, out unknown)) {
+                result.hasDynamicEnumExtension = true;
+              } else if(unknown is int) {
                 if (unknownFields == null) {
                   unknownFields = pb::UnknownFieldSet.CreateBuilder(this.UnknownFields);
                 }
-                unknownFields.MergeVarintField(2002, (ulong) rawValue);
-              } else {
-                DynamicEnumExtension = (global::Google.ProtocolBuffers.TestProtos.TestDynamicExtensions.Types.DynamicEnumType) rawValue;
+                unknownFields.MergeVarintField(2002, (ulong)(int)unknown);
               }
               break;
             }
@@ -17259,16 +17181,11 @@
               break;
             }
             case 16042: {
-              AddRepeatedExtension(input.ReadString());
+              input.ReadPrimitiveArray(pbd::FieldType.String, tag, field_name, result.repeatedExtension_);
               break;
             }
             case 16050: {
-              int length = input.ReadInt32();
-              int limit = input.PushLimit(length);
-              while (!input.ReachedLimit) {
-                AddPackedExtension(input.ReadSInt32());
-              }
-              input.PopLimit(limit);
+              input.ReadPrimitiveArray(pbd::FieldType.SInt32, tag, field_name, result.packedExtension_);
               break;
             }
           }
@@ -17795,31 +17712,31 @@
               if (unknownFields == null) {
                 unknownFields = pb::UnknownFieldSet.CreateBuilder(this.UnknownFields);
               }
-              ParseUnknownField(input, unknownFields, extensionRegistry, tag);
+              ParseUnknownField(input, unknownFields, extensionRegistry, tag, field_name);
               break;
             }
             case 101: {
-              AddRepeatedFixed32(input.ReadFixed32());
+              input.ReadPrimitiveArray(pbd::FieldType.Fixed32, tag, field_name, result.repeatedFixed32_);
               break;
             }
             case 104: {
-              AddRepeatedInt32(input.ReadInt32());
+              input.ReadPrimitiveArray(pbd::FieldType.Int32, tag, field_name, result.repeatedInt32_);
               break;
             }
             case 16369: {
-              AddRepeatedFixed64(input.ReadFixed64());
+              input.ReadPrimitiveArray(pbd::FieldType.Fixed64, tag, field_name, result.repeatedFixed64_);
               break;
             }
             case 16376: {
-              AddRepeatedInt64(input.ReadInt64());
+              input.ReadPrimitiveArray(pbd::FieldType.Int64, tag, field_name, result.repeatedInt64_);
               break;
             }
             case 2097141: {
-              AddRepeatedFloat(input.ReadFloat());
+              input.ReadPrimitiveArray(pbd::FieldType.Float, tag, field_name, result.repeatedFloat_);
               break;
             }
             case 2097144: {
-              AddRepeatedUint64(input.ReadUInt64());
+              input.ReadPrimitiveArray(pbd::FieldType.UInt64, tag, field_name, result.repeatedUint64_);
               break;
             }
           }
@@ -18173,7 +18090,7 @@
               if (unknownFields == null) {
                 unknownFields = pb::UnknownFieldSet.CreateBuilder(this.UnknownFields);
               }
-              ParseUnknownField(input, unknownFields, extensionRegistry, tag);
+              ParseUnknownField(input, unknownFields, extensionRegistry, tag, field_name);
               break;
             }
           }
@@ -18356,7 +18273,7 @@
               if (unknownFields == null) {
                 unknownFields = pb::UnknownFieldSet.CreateBuilder(this.UnknownFields);
               }
-              ParseUnknownField(input, unknownFields, extensionRegistry, tag);
+              ParseUnknownField(input, unknownFields, extensionRegistry, tag, field_name);
               break;
             }
           }
@@ -18539,7 +18456,7 @@
               if (unknownFields == null) {
                 unknownFields = pb::UnknownFieldSet.CreateBuilder(this.UnknownFields);
               }
-              ParseUnknownField(input, unknownFields, extensionRegistry, tag);
+              ParseUnknownField(input, unknownFields, extensionRegistry, tag, field_name);
               break;
             }
           }
@@ -18722,7 +18639,7 @@
               if (unknownFields == null) {
                 unknownFields = pb::UnknownFieldSet.CreateBuilder(this.UnknownFields);
               }
-              ParseUnknownField(input, unknownFields, extensionRegistry, tag);
+              ParseUnknownField(input, unknownFields, extensionRegistry, tag, field_name);
               break;
             }
           }
diff --git a/src/ProtocolBuffers.Test/TestProtos/UnitTestRpcInterop.cs b/src/ProtocolBuffers.Test/TestProtos/UnitTestRpcInterop.cs
index b4f7a51..58ceef7 100644
--- a/src/ProtocolBuffers.Test/TestProtos/UnitTestRpcInterop.cs
+++ b/src/ProtocolBuffers.Test/TestProtos/UnitTestRpcInterop.cs
@@ -269,11 +269,11 @@
               if (unknownFields == null) {
                 unknownFields = pb::UnknownFieldSet.CreateBuilder(this.UnknownFields);
               }
-              ParseUnknownField(input, unknownFields, extensionRegistry, tag);
+              ParseUnknownField(input, unknownFields, extensionRegistry, tag, field_name);
               break;
             }
             case 10: {
-              AddCriteria(input.ReadString());
+              input.ReadPrimitiveArray(pbd::FieldType.String, tag, field_name, result.criteria_);
               break;
             }
           }
@@ -553,15 +553,15 @@
                   if (unknownFields == null) {
                     unknownFields = pb::UnknownFieldSet.CreateBuilder(this.UnknownFields);
                   }
-                  ParseUnknownField(input, unknownFields, extensionRegistry, tag);
+                  ParseUnknownField(input, unknownFields, extensionRegistry, tag, field_name);
                   break;
                 }
                 case 10: {
-                  Url = input.ReadString();
+                  result.hasUrl |= input.ReadString(ref result.url_);
                   break;
                 }
                 case 18: {
-                  Name = input.ReadString();
+                  result.hasName |= input.ReadString(ref result.name_);
                   break;
                 }
               }
@@ -785,13 +785,11 @@
               if (unknownFields == null) {
                 unknownFields = pb::UnknownFieldSet.CreateBuilder(this.UnknownFields);
               }
-              ParseUnknownField(input, unknownFields, extensionRegistry, tag);
+              ParseUnknownField(input, unknownFields, extensionRegistry, tag, field_name);
               break;
             }
             case 10: {
-              global::Google.ProtocolBuffers.TestProtos.SearchResponse.Types.ResultItem.Builder subBuilder = global::Google.ProtocolBuffers.TestProtos.SearchResponse.Types.ResultItem.CreateBuilder();
-              input.ReadMessage(subBuilder, extensionRegistry);
-              AddResults(subBuilder.BuildPartial());
+              input.ReadMessageArray(tag, field_name, result.results_, global::Google.ProtocolBuffers.TestProtos.SearchResponse.Types.ResultItem.DefaultInstance, extensionRegistry);
               break;
             }
           }
@@ -1060,11 +1058,11 @@
               if (unknownFields == null) {
                 unknownFields = pb::UnknownFieldSet.CreateBuilder(this.UnknownFields);
               }
-              ParseUnknownField(input, unknownFields, extensionRegistry, tag);
+              ParseUnknownField(input, unknownFields, extensionRegistry, tag, field_name);
               break;
             }
             case 10: {
-              AddCriteria(input.ReadString());
+              input.ReadPrimitiveArray(pbd::FieldType.String, tag, field_name, result.criteria_);
               break;
             }
             case 18: {
diff --git a/src/ProtocolBuffers.Test/TestProtos/UnitTestXmlSerializerTestProtoFile.cs b/src/ProtocolBuffers.Test/TestProtos/UnitTestXmlSerializerTestProtoFile.cs
index 1b523c3..2476cf1 100644
--- a/src/ProtocolBuffers.Test/TestProtos/UnitTestXmlSerializerTestProtoFile.cs
+++ b/src/ProtocolBuffers.Test/TestProtos/UnitTestXmlSerializerTestProtoFile.cs
@@ -337,23 +337,24 @@
               if (unknownFields == null) {
                 unknownFields = pb::UnknownFieldSet.CreateBuilder(this.UnknownFields);
               }
-              ParseUnknownField(input, unknownFields, extensionRegistry, tag);
+              ParseUnknownField(input, unknownFields, extensionRegistry, tag, field_name);
               break;
             }
             case 24: {
-              int rawValue = input.ReadEnum();
-              if (!global::System.Enum.IsDefined(typeof(global::Google.ProtocolBuffers.TestProtos.EnumOptions), rawValue)) {
+              scg::ICollection<object> unknownItems;
+              input.ReadEnumArray<global::Google.ProtocolBuffers.TestProtos.EnumOptions>(tag, field_name, result.options_, out unknownItems);
+              if (unknownItems != null) {
                 if (unknownFields == null) {
                   unknownFields = pb::UnknownFieldSet.CreateBuilder(this.UnknownFields);
                 }
-                unknownFields.MergeVarintField(3, (ulong) rawValue);
-              } else {
-                AddOptions((global::Google.ProtocolBuffers.TestProtos.EnumOptions) rawValue);
+                foreach (object rawValue in unknownItems)
+                  if (rawValue is int)
+                    unknownFields.MergeVarintField(3, (ulong)(int)rawValue);
               }
               break;
             }
             case 34: {
-              Binary = input.ReadBytes();
+              result.hasBinary |= input.ReadBytes(ref result.binary_);
               break;
             }
           }
@@ -581,7 +582,7 @@
               if (unknownFields == null) {
                 unknownFields = pb::UnknownFieldSet.CreateBuilder(this.UnknownFields);
               }
-              ParseUnknownField(input, unknownFields, extensionRegistry, tag);
+              ParseUnknownField(input, unknownFields, extensionRegistry, tag, field_name);
               break;
             }
           }
@@ -842,23 +843,24 @@
                   if (unknownFields == null) {
                     unknownFields = pb::UnknownFieldSet.CreateBuilder(this.UnknownFields);
                   }
-                  ParseUnknownField(input, unknownFields, extensionRegistry, tag);
+                  ParseUnknownField(input, unknownFields, extensionRegistry, tag, field_name);
                   break;
                 }
                 case 24: {
-                  int rawValue = input.ReadEnum();
-                  if (!global::System.Enum.IsDefined(typeof(global::Google.ProtocolBuffers.TestProtos.EnumOptions), rawValue)) {
+                  scg::ICollection<object> unknownItems;
+                  input.ReadEnumArray<global::Google.ProtocolBuffers.TestProtos.EnumOptions>(tag, field_name, result.options_, out unknownItems);
+                  if (unknownItems != null) {
                     if (unknownFields == null) {
                       unknownFields = pb::UnknownFieldSet.CreateBuilder(this.UnknownFields);
                     }
-                    unknownFields.MergeVarintField(3, (ulong) rawValue);
-                  } else {
-                    AddOptions((global::Google.ProtocolBuffers.TestProtos.EnumOptions) rawValue);
+                    foreach (object rawValue in unknownItems)
+                      if (rawValue is int)
+                        unknownFields.MergeVarintField(3, (ulong)(int)rawValue);
                   }
                   break;
                 }
                 case 34: {
-                  Binary = input.ReadBytes();
+                  result.hasBinary |= input.ReadBytes(ref result.binary_);
                   break;
                 }
               }
@@ -1221,7 +1223,7 @@
               if (unknownFields == null) {
                 unknownFields = pb::UnknownFieldSet.CreateBuilder(this.UnknownFields);
               }
-              ParseUnknownField(input, unknownFields, extensionRegistry, tag);
+              ParseUnknownField(input, unknownFields, extensionRegistry, tag, field_name);
               break;
             }
             case 10: {
@@ -1234,29 +1236,27 @@
               break;
             }
             case 16: {
-              AddNumbers(input.ReadInt32());
+              input.ReadPrimitiveArray(pbd::FieldType.Int32, tag, field_name, result.numbers_);
               break;
             }
             case 26: {
-              Text = input.ReadString();
+              result.hasText |= input.ReadString(ref result.text_);
               break;
             }
             case 40: {
-              Valid = input.ReadBool();
+              result.hasValid |= input.ReadBool(ref result.valid_);
               break;
             }
             case 48: {
-              Number = input.ReadInt64();
+              result.hasNumber |= input.ReadInt64(ref result.number_);
               break;
             }
             case 3211: {
-              global::Google.ProtocolBuffers.TestProtos.TestXmlMessage.Types.Children.Builder subBuilder = global::Google.ProtocolBuffers.TestProtos.TestXmlMessage.Types.Children.CreateBuilder();
-              input.ReadGroup(401, subBuilder, extensionRegistry);
-              AddChildren(subBuilder.BuildPartial());
+              input.ReadGroupArray(tag, field_name, result.children_, global::Google.ProtocolBuffers.TestProtos.TestXmlMessage.Types.Children.DefaultInstance, extensionRegistry);
               break;
             }
             case 5602: {
-              AddTextlines(input.ReadString());
+              input.ReadPrimitiveArray(pbd::FieldType.String, tag, field_name, result.textlines_);
               break;
             }
           }
@@ -1642,11 +1642,11 @@
               if (unknownFields == null) {
                 unknownFields = pb::UnknownFieldSet.CreateBuilder(this.UnknownFields);
               }
-              ParseUnknownField(input, unknownFields, extensionRegistry, tag);
+              ParseUnknownField(input, unknownFields, extensionRegistry, tag, field_name);
               break;
             }
             case 8: {
-              Number = input.ReadInt32();
+              result.hasNumber |= input.ReadInt32(ref result.number_);
               break;
             }
           }
diff --git a/src/ProtocolBuffers/CodedInputStream.cs b/src/ProtocolBuffers/CodedInputStream.cs
index 33986d3..92e547f 100644
--- a/src/ProtocolBuffers/CodedInputStream.cs
+++ b/src/ProtocolBuffers/CodedInputStream.cs
@@ -201,88 +201,100 @@
         /// <summary>
         /// Read a double field from the stream.
         /// </summary>
-        public double ReadDouble()
+        public bool ReadDouble(ref double value)
         {
 #if SILVERLIGHT2 || COMPACT_FRAMEWORK_35
-            byte[] bytes = ReadRawBytes(8);
-            return BitConverter.ToDouble(bytes, 0);
+            byte[] rawBytes = ReadRawBytes(8);
+            if (!BitConverter.IsLittleEndian) 
+                Array.Reverse(rawBytes);
+            value = BitConverter.ToDouble(rawBytes, 0);
+            return true;
 #else
-      return BitConverter.Int64BitsToDouble((long) ReadRawLittleEndian64());
+            value = BitConverter.Int64BitsToDouble((long) ReadRawLittleEndian64());
+            return true;
 #endif
         }
 
         /// <summary>
         /// Read a float field from the stream.
         /// </summary>
-        public float ReadFloat()
+        public bool ReadFloat(ref float value)
         {
-            // TODO(jonskeet): Test this on different endiannesses
-            uint raw = ReadRawLittleEndian32();
-            byte[] rawBytes = BitConverter.GetBytes(raw);
-            return BitConverter.ToSingle(rawBytes, 0);
+            byte[] rawBytes = ReadRawBytes(4);
+            if (!BitConverter.IsLittleEndian)
+                Array.Reverse(rawBytes);
+            value = BitConverter.ToSingle(rawBytes, 0);
+            return true;
         }
 
         /// <summary>
         /// Read a uint64 field from the stream.
         /// </summary>
         [CLSCompliant(false)]
-        public ulong ReadUInt64()
+        public bool ReadUInt64(ref ulong value)
         {
-            return ReadRawVarint64();
+            value = ReadRawVarint64();
+            return true;
         }
 
         /// <summary>
         /// Read an int64 field from the stream.
         /// </summary>
-        public long ReadInt64()
+        public bool ReadInt64(ref long value)
         {
-            return (long) ReadRawVarint64();
+            value = (long) ReadRawVarint64();
+            return true;
         }
 
         /// <summary>
         /// Read an int32 field from the stream.
         /// </summary>
-        public int ReadInt32()
+        public bool ReadInt32(ref int value)
         {
-            return (int) ReadRawVarint32();
+            value = (int)ReadRawVarint32();
+            return true;
         }
 
         /// <summary>
         /// Read a fixed64 field from the stream.
         /// </summary>
         [CLSCompliant(false)]
-        public ulong ReadFixed64()
+        public bool ReadFixed64(ref ulong value)
         {
-            return ReadRawLittleEndian64();
+            value = ReadRawLittleEndian64();
+            return true;
         }
 
         /// <summary>
         /// Read a fixed32 field from the stream.
         /// </summary>
         [CLSCompliant(false)]
-        public uint ReadFixed32()
+        public bool ReadFixed32(ref uint value)
         {
-            return ReadRawLittleEndian32();
+            value = ReadRawLittleEndian32();
+            return true;
         }
 
         /// <summary>
         /// Read a bool field from the stream.
         /// </summary>
-        public bool ReadBool()
+        public bool ReadBool(ref bool value)
         {
-            return ReadRawVarint32() != 0;
+            value = ReadRawVarint32() != 0;
+            return true;
         }
 
         /// <summary>
         /// Reads a string field from the stream.
         /// </summary>
-        public String ReadString()
+        public bool ReadString(ref string value)
         {
             int size = (int) ReadRawVarint32();
             // No need to read any data for an empty string.
             if (size == 0)
             {
-                return "";
+                value = "";
+                return true;
             }
             if (size <= bufferSize - bufferPos)
             {
@@ -290,10 +302,12 @@
                 //   just copy directly from it.
                 String result = Encoding.UTF8.GetString(buffer, bufferPos, size);
                 bufferPos += size;
-                return result;
+                value = result;
+                return true;
             }
             // Slow path: Build a byte array first then copy it.
-            return Encoding.UTF8.GetString(ReadRawBytes(size), 0, size);
+            value = Encoding.UTF8.GetString(ReadRawBytes(size), 0, size);
+            return true;
         }
 
         /// <summary>
@@ -350,7 +364,7 @@
         /// <summary>
         /// Reads a bytes field value from the stream.
         /// </summary>   
-        public ByteString ReadBytes()
+        public bool ReadBytes(ref ByteString value)
         {
             int size = (int) ReadRawVarint32();
             if (size < bufferSize - bufferPos && size > 0)
@@ -359,12 +373,14 @@
                 //   just copy directly from it.
                 ByteString result = ByteString.CopyFrom(buffer, bufferPos, size);
                 bufferPos += size;
-                return result;
+                value = result;
+                return true;
             }
             else
             {
                 // Slow path:  Build a byte array first then copy it.
-                return ByteString.AttachBytes(ReadRawBytes(size));
+                value = ByteString.AttachBytes(ReadRawBytes(size));
+                return true;
             }
         }
 
@@ -372,90 +388,358 @@
         /// Reads a uint32 field value from the stream.
         /// </summary>   
         [CLSCompliant(false)]
-        public uint ReadUInt32()
+        public bool ReadUInt32(ref uint value)
         {
-            return ReadRawVarint32();
+            value = ReadRawVarint32();
+            return true;
         }
 
         /// <summary>
         /// Reads an enum field value from the stream. The caller is responsible
         /// for converting the numeric value to an actual enum.
         /// </summary>   
-        public int ReadEnum()
+        public bool ReadEnum(ref IEnumLite value, out object unknown, IEnumLiteMap mapping)
         {
-            return (int) ReadRawVarint32();
+            int rawValue = (int)ReadRawVarint32();
+            
+            value = mapping.FindValueByNumber(rawValue);
+            if (value != null)
+            {
+                unknown = null;
+                return true;
+            }
+            unknown = rawValue;
+            return false;
+        }
+
+        /// <summary>
+        /// Reads an enum field value from the stream. If the enum is valid for type T,
+        /// then the ref value is set and it returns true.  Otherwise the unkown output
+        /// value is set and this method returns false.
+        /// </summary>   
+        [CLSCompliant(false)]
+        public bool ReadEnum<T>(ref T value, out object unknown)
+            where T : struct, IComparable, IFormattable, IConvertible
+        {
+            int number = (int)ReadRawVarint32();
+            if (Enum.IsDefined(typeof(T), number))
+            {
+                unknown = null;
+                value = (T)(object)number;
+                return true;
+            }
+            unknown = number;
+            return false;
         }
 
         /// <summary>
         /// Reads an sfixed32 field value from the stream.
         /// </summary>   
-        public int ReadSFixed32()
+        public bool ReadSFixed32(ref int value)
         {
-            return (int) ReadRawLittleEndian32();
+            value = (int)ReadRawLittleEndian32();
+            return true;
         }
 
         /// <summary>
         /// Reads an sfixed64 field value from the stream.
         /// </summary>   
-        public long ReadSFixed64()
+        public bool ReadSFixed64(ref long value)
         {
-            return (long) ReadRawLittleEndian64();
+            value = (long)ReadRawLittleEndian64();
+            return true;
         }
 
         /// <summary>
         /// Reads an sint32 field value from the stream.
         /// </summary>   
-        public int ReadSInt32()
+        public bool ReadSInt32(ref int value)
         {
-            return DecodeZigZag32(ReadRawVarint32());
+            value = DecodeZigZag32(ReadRawVarint32());
+            return true;
         }
 
         /// <summary>
         /// Reads an sint64 field value from the stream.
         /// </summary>   
-        public long ReadSInt64()
+        public bool ReadSInt64(ref long value)
         {
-            return DecodeZigZag64(ReadRawVarint64());
+            value = DecodeZigZag64(ReadRawVarint64());
+            return true;
+        }
+
+        [CLSCompliant(false)]
+        public void ReadPrimitiveArray<T>(FieldType fieldType, uint fieldTag, string fieldName, ICollection<T> list)
+        {
+            WireFormat.WireType normal = WireFormat.GetWireType(fieldType);
+            WireFormat.WireType wformat = WireFormat.GetTagWireType(fieldTag);
+            
+            // 2.3 allows packed form even if the field is not declared packed.
+            if(normal != wformat && wformat == WireFormat.WireType.LengthDelimited)
+            {
+                int length = (int)(ReadRawVarint32() & int.MaxValue);
+                int limit = PushLimit(length);
+                while (!ReachedLimit)
+                {
+                    Object value = null;
+                    if(ReadPrimitiveField(fieldType, ref value))
+                        list.Add((T)value);
+                }
+                PopLimit(limit);
+            }
+            else
+            {
+                Object value = null;
+                if (ReadPrimitiveField(fieldType, ref value))
+                    list.Add((T)value);
+            }
+        }
+
+        [CLSCompliant(false)]
+        public void ReadEnumArray(uint fieldTag, string fieldName, ICollection<IEnumLite> list, out ICollection<object> unknown, IEnumLiteMap mapping)
+        {
+            unknown = null;
+            object unkval;
+            IEnumLite value = null;
+            WireFormat.WireType wformat = WireFormat.GetTagWireType(fieldTag);
+
+            // 2.3 allows packed form even if the field is not declared packed.
+            if (wformat == WireFormat.WireType.LengthDelimited)
+            {
+                int length = (int)(ReadRawVarint32() & int.MaxValue);
+                int limit = PushLimit(length);
+                while (!ReachedLimit)
+                {
+                    if (ReadEnum(ref value, out unkval, mapping))
+                        list.Add(value);
+                    else
+                    {
+                        if (unknown == null)
+                            unknown = new List<object>();
+                        unknown.Add(unkval);
+                    }
+                }
+                PopLimit(limit);
+            }
+            else
+            {
+                if (ReadEnum(ref value, out unkval, mapping))
+                    list.Add(value);
+                else
+                    unknown = new object[] { unkval };
+            }
+        }
+
+        [CLSCompliant(false)]
+        public void ReadEnumArray<T>(uint fieldTag, string fieldName, ICollection<T> list, out ICollection<object> unknown)
+            where T : struct, IComparable, IFormattable, IConvertible
+        {
+            unknown = null;
+            object unkval;
+            T value = default(T);
+            WireFormat.WireType wformat = WireFormat.GetTagWireType(fieldTag);
+
+            // 2.3 allows packed form even if the field is not declared packed.
+            if (wformat == WireFormat.WireType.LengthDelimited)
+            {
+                int length = (int)(ReadRawVarint32() & int.MaxValue);
+                int limit = PushLimit(length);
+                while (!ReachedLimit)
+                {
+                    if (ReadEnum<T>(ref value, out unkval))
+                        list.Add(value);
+                    else
+                    {
+                        if (unknown == null)
+                            unknown = new List<object>();
+                        unknown.Add(unkval);
+                    }
+                }
+                PopLimit(limit);
+            }
+            else
+            {
+                if (ReadEnum(ref value, out unkval))
+                    list.Add(value);
+                else
+                    unknown = new object[] { unkval };
+            }
+        }
+
+        [CLSCompliant(false)]
+        public void ReadMessageArray<T>(uint fieldTag, string fieldName, ICollection<T> list, T messageType, ExtensionRegistry registry) where T : IMessageLite
+        {
+            IBuilderLite builder = messageType.WeakCreateBuilderForType();
+            ReadMessage(builder, registry);
+            list.Add((T)builder.WeakBuildPartial());
+        }
+
+        [CLSCompliant(false)]
+        public void ReadGroupArray<T>(uint fieldTag, string fieldName, ICollection<T> list, T messageType, ExtensionRegistry registry) where T : IMessageLite
+        {
+            IBuilderLite builder = messageType.WeakCreateBuilderForType();
+            ReadGroup(WireFormat.GetTagFieldNumber(fieldTag), builder, registry);
+            list.Add((T)builder.WeakBuildPartial());
         }
 
         /// <summary>
         /// Reads a field of any primitive type. Enums, groups and embedded
         /// messages are not handled by this method.
         /// </summary>
-        public object ReadPrimitiveField(FieldType fieldType)
+        public bool ReadPrimitiveField(FieldType fieldType, ref object value)
         {
             switch (fieldType)
             {
                 case FieldType.Double:
-                    return ReadDouble();
+                    {
+                        double tmp = 0;
+                        if (ReadDouble(ref tmp))
+                        {
+                            value = tmp;
+                            return true;
+                        }
+                        return false;
+                    }
                 case FieldType.Float:
-                    return ReadFloat();
+                    {
+                        float tmp = 0;
+                        if (ReadFloat(ref tmp))
+                        {
+                            value = tmp;
+                            return true;
+                        }
+                        return false;
+                    }
                 case FieldType.Int64:
-                    return ReadInt64();
+                    {
+                        long tmp = 0;
+                        if (ReadInt64(ref tmp))
+                        {
+                            value = tmp;
+                            return true;
+                        }
+                        return false;
+                    }
                 case FieldType.UInt64:
-                    return ReadUInt64();
+                    {
+                        ulong tmp = 0;
+                        if (ReadUInt64(ref tmp))
+                        {
+                            value = tmp;
+                            return true;
+                        }
+                        return false;
+                    }
                 case FieldType.Int32:
-                    return ReadInt32();
+                    {
+                        int tmp = 0;
+                        if (ReadInt32(ref tmp))
+                        {
+                            value = tmp;
+                            return true;
+                        }
+                        return false;
+                    }
                 case FieldType.Fixed64:
-                    return ReadFixed64();
+                    {
+                        ulong tmp = 0;
+                        if (ReadFixed64(ref tmp))
+                        {
+                            value = tmp;
+                            return true;
+                        }
+                        return false;
+                    }
                 case FieldType.Fixed32:
-                    return ReadFixed32();
+                    {
+                        uint tmp = 0;
+                        if (ReadFixed32(ref tmp))
+                        {
+                            value = tmp;
+                            return true;
+                        }
+                        return false;
+                    }
                 case FieldType.Bool:
-                    return ReadBool();
+                    {
+                        bool tmp = false;
+                        if (ReadBool(ref tmp))
+                        {
+                            value = tmp;
+                            return true;
+                        }
+                        return false;
+                    }
                 case FieldType.String:
-                    return ReadString();
+                    {
+                        string tmp = null;
+                        if (ReadString(ref tmp))
+                        {
+                            value = tmp;
+                            return true;
+                        }
+                        return false;
+                    }
                 case FieldType.Bytes:
-                    return ReadBytes();
+                    {
+                        ByteString tmp = null;
+                        if (ReadBytes(ref tmp))
+                        {
+                            value = tmp;
+                            return true;
+                        }
+                        return false;
+                    }
                 case FieldType.UInt32:
-                    return ReadUInt32();
+                    {
+                        uint tmp = 0;
+                        if (ReadUInt32(ref tmp))
+                        {
+                            value = tmp;
+                            return true;
+                        }
+                        return false;
+                    }
                 case FieldType.SFixed32:
-                    return ReadSFixed32();
+                    {
+                        int tmp = 0;
+                        if (ReadSFixed32(ref tmp))
+                        {
+                            value = tmp;
+                            return true;
+                        }
+                        return false;
+                    }
                 case FieldType.SFixed64:
-                    return ReadSFixed64();
+                    {
+                        long tmp = 0;
+                        if (ReadSFixed64(ref tmp))
+                        {
+                            value = tmp;
+                            return true;
+                        }
+                        return false;
+                    }
                 case FieldType.SInt32:
-                    return ReadSInt32();
+                    {
+                        int tmp = 0;
+                        if (ReadSInt32(ref tmp))
+                        {
+                            value = tmp;
+                            return true;
+                        }
+                        return false;
+                    }
                 case FieldType.SInt64:
-                    return ReadSInt64();
+                    {
+                        long tmp = 0;
+                        if (ReadSInt64(ref tmp))
+                        {
+                            value = tmp;
+                            return true;
+                        }
+                        return false;
+                    }
                 case FieldType.Group:
                     throw new ArgumentException("ReadPrimitiveField() cannot handle nested groups.");
                 case FieldType.Message:
@@ -1047,7 +1331,7 @@
             switch (WireFormat.GetTagWireType(tag))
             {
                 case WireFormat.WireType.Varint:
-                    ReadInt32();
+                    ReadRawVarint64();
                     return true;
                 case WireFormat.WireType.Fixed64:
                     ReadRawLittleEndian64();
diff --git a/src/ProtocolBuffers/DescriptorProtos/CSharpOptions.cs b/src/ProtocolBuffers/DescriptorProtos/CSharpOptions.cs
index 36040cb..5dbab8c 100644
--- a/src/ProtocolBuffers/DescriptorProtos/CSharpOptions.cs
+++ b/src/ProtocolBuffers/DescriptorProtos/CSharpOptions.cs
@@ -531,66 +531,66 @@
               if (unknownFields == null) {
                 unknownFields = pb::UnknownFieldSet.CreateBuilder(this.UnknownFields);
               }
-              ParseUnknownField(input, unknownFields, extensionRegistry, tag);
+              ParseUnknownField(input, unknownFields, extensionRegistry, tag, field_name);
               break;
             }
             case 10: {
-              Namespace = input.ReadString();
+              result.hasNamespace |= input.ReadString(ref result.namespace_);
               break;
             }
             case 18: {
-              UmbrellaClassname = input.ReadString();
+              result.hasUmbrellaClassname |= input.ReadString(ref result.umbrellaClassname_);
               break;
             }
             case 24: {
-              PublicClasses = input.ReadBool();
+              result.hasPublicClasses |= input.ReadBool(ref result.publicClasses_);
               break;
             }
             case 32: {
-              MultipleFiles = input.ReadBool();
+              result.hasMultipleFiles |= input.ReadBool(ref result.multipleFiles_);
               break;
             }
             case 40: {
-              NestClasses = input.ReadBool();
+              result.hasNestClasses |= input.ReadBool(ref result.nestClasses_);
               break;
             }
             case 48: {
-              CodeContracts = input.ReadBool();
+              result.hasCodeContracts |= input.ReadBool(ref result.codeContracts_);
               break;
             }
             case 56: {
-              ExpandNamespaceDirectories = input.ReadBool();
+              result.hasExpandNamespaceDirectories |= input.ReadBool(ref result.expandNamespaceDirectories_);
               break;
             }
             case 64: {
-              ClsCompliance = input.ReadBool();
+              result.hasClsCompliance |= input.ReadBool(ref result.clsCompliance_);
               break;
             }
             case 1770: {
-              FileExtension = input.ReadString();
+              result.hasFileExtension |= input.ReadString(ref result.fileExtension_);
               break;
             }
             case 1778: {
-              UmbrellaNamespace = input.ReadString();
+              result.hasUmbrellaNamespace |= input.ReadString(ref result.umbrellaNamespace_);
               break;
             }
             case 1786: {
-              OutputDirectory = input.ReadString();
+              result.hasOutputDirectory |= input.ReadString(ref result.outputDirectory_);
               break;
             }
             case 1792: {
-              IgnoreGoogleProtobuf = input.ReadBool();
+              result.hasIgnoreGoogleProtobuf |= input.ReadBool(ref result.ignoreGoogleProtobuf_);
               break;
             }
             case 1800: {
-              int rawValue = input.ReadEnum();
-              if (!global::System.Enum.IsDefined(typeof(global::Google.ProtocolBuffers.DescriptorProtos.CSharpServiceType), rawValue)) {
+              object unknown;
+              if(input.ReadEnum(ref result.serviceGeneratorType_, out unknown)) {
+                result.hasServiceGeneratorType = true;
+              } else if(unknown is int) {
                 if (unknownFields == null) {
                   unknownFields = pb::UnknownFieldSet.CreateBuilder(this.UnknownFields);
                 }
-                unknownFields.MergeVarintField(225, (ulong) rawValue);
-              } else {
-                ServiceGeneratorType = (global::Google.ProtocolBuffers.DescriptorProtos.CSharpServiceType) rawValue;
+                unknownFields.MergeVarintField(225, (ulong)(int)unknown);
               }
               break;
             }
@@ -1032,11 +1032,11 @@
               if (unknownFields == null) {
                 unknownFields = pb::UnknownFieldSet.CreateBuilder(this.UnknownFields);
               }
-              ParseUnknownField(input, unknownFields, extensionRegistry, tag);
+              ParseUnknownField(input, unknownFields, extensionRegistry, tag, field_name);
               break;
             }
             case 10: {
-              PropertyName = input.ReadString();
+              result.hasPropertyName |= input.ReadString(ref result.propertyName_);
               break;
             }
           }
@@ -1257,11 +1257,11 @@
               if (unknownFields == null) {
                 unknownFields = pb::UnknownFieldSet.CreateBuilder(this.UnknownFields);
               }
-              ParseUnknownField(input, unknownFields, extensionRegistry, tag);
+              ParseUnknownField(input, unknownFields, extensionRegistry, tag, field_name);
               break;
             }
             case 10: {
-              InterfaceId = input.ReadString();
+              result.hasInterfaceId |= input.ReadString(ref result.interfaceId_);
               break;
             }
           }
@@ -1482,11 +1482,11 @@
               if (unknownFields == null) {
                 unknownFields = pb::UnknownFieldSet.CreateBuilder(this.UnknownFields);
               }
-              ParseUnknownField(input, unknownFields, extensionRegistry, tag);
+              ParseUnknownField(input, unknownFields, extensionRegistry, tag, field_name);
               break;
             }
             case 8: {
-              DispatchId = input.ReadInt32();
+              result.hasDispatchId |= input.ReadInt32(ref result.dispatchId_);
               break;
             }
           }
diff --git a/src/ProtocolBuffers/DescriptorProtos/DescriptorProtoFile.cs b/src/ProtocolBuffers/DescriptorProtos/DescriptorProtoFile.cs
index 0dca046..365a044 100644
--- a/src/ProtocolBuffers/DescriptorProtos/DescriptorProtoFile.cs
+++ b/src/ProtocolBuffers/DescriptorProtos/DescriptorProtoFile.cs
@@ -417,13 +417,11 @@
               if (unknownFields == null) {
                 unknownFields = pb::UnknownFieldSet.CreateBuilder(this.UnknownFields);
               }
-              ParseUnknownField(input, unknownFields, extensionRegistry, tag);
+              ParseUnknownField(input, unknownFields, extensionRegistry, tag, field_name);
               break;
             }
             case 10: {
-              global::Google.ProtocolBuffers.DescriptorProtos.FileDescriptorProto.Builder subBuilder = global::Google.ProtocolBuffers.DescriptorProtos.FileDescriptorProto.CreateBuilder();
-              input.ReadMessage(subBuilder, extensionRegistry);
-              AddFile(subBuilder.BuildPartial());
+              input.ReadMessageArray(tag, field_name, result.file_, global::Google.ProtocolBuffers.DescriptorProtos.FileDescriptorProto.DefaultInstance, extensionRegistry);
               break;
             }
           }
@@ -831,43 +829,35 @@
               if (unknownFields == null) {
                 unknownFields = pb::UnknownFieldSet.CreateBuilder(this.UnknownFields);
               }
-              ParseUnknownField(input, unknownFields, extensionRegistry, tag);
+              ParseUnknownField(input, unknownFields, extensionRegistry, tag, field_name);
               break;
             }
             case 10: {
-              Name = input.ReadString();
+              result.hasName |= input.ReadString(ref result.name_);
               break;
             }
             case 18: {
-              Package = input.ReadString();
+              result.hasPackage |= input.ReadString(ref result.package_);
               break;
             }
             case 26: {
-              AddDependency(input.ReadString());
+              input.ReadPrimitiveArray(pbd::FieldType.String, tag, field_name, result.dependency_);
               break;
             }
             case 34: {
-              global::Google.ProtocolBuffers.DescriptorProtos.DescriptorProto.Builder subBuilder = global::Google.ProtocolBuffers.DescriptorProtos.DescriptorProto.CreateBuilder();
-              input.ReadMessage(subBuilder, extensionRegistry);
-              AddMessageType(subBuilder.BuildPartial());
+              input.ReadMessageArray(tag, field_name, result.messageType_, global::Google.ProtocolBuffers.DescriptorProtos.DescriptorProto.DefaultInstance, extensionRegistry);
               break;
             }
             case 42: {
-              global::Google.ProtocolBuffers.DescriptorProtos.EnumDescriptorProto.Builder subBuilder = global::Google.ProtocolBuffers.DescriptorProtos.EnumDescriptorProto.CreateBuilder();
-              input.ReadMessage(subBuilder, extensionRegistry);
-              AddEnumType(subBuilder.BuildPartial());
+              input.ReadMessageArray(tag, field_name, result.enumType_, global::Google.ProtocolBuffers.DescriptorProtos.EnumDescriptorProto.DefaultInstance, extensionRegistry);
               break;
             }
             case 50: {
-              global::Google.ProtocolBuffers.DescriptorProtos.ServiceDescriptorProto.Builder subBuilder = global::Google.ProtocolBuffers.DescriptorProtos.ServiceDescriptorProto.CreateBuilder();
-              input.ReadMessage(subBuilder, extensionRegistry);
-              AddService(subBuilder.BuildPartial());
+              input.ReadMessageArray(tag, field_name, result.service_, global::Google.ProtocolBuffers.DescriptorProtos.ServiceDescriptorProto.DefaultInstance, extensionRegistry);
               break;
             }
             case 58: {
-              global::Google.ProtocolBuffers.DescriptorProtos.FieldDescriptorProto.Builder subBuilder = global::Google.ProtocolBuffers.DescriptorProtos.FieldDescriptorProto.CreateBuilder();
-              input.ReadMessage(subBuilder, extensionRegistry);
-              AddExtension(subBuilder.BuildPartial());
+              input.ReadMessageArray(tag, field_name, result.extension_, global::Google.ProtocolBuffers.DescriptorProtos.FieldDescriptorProto.DefaultInstance, extensionRegistry);
               break;
             }
             case 66: {
@@ -1381,15 +1371,15 @@
                   if (unknownFields == null) {
                     unknownFields = pb::UnknownFieldSet.CreateBuilder(this.UnknownFields);
                   }
-                  ParseUnknownField(input, unknownFields, extensionRegistry, tag);
+                  ParseUnknownField(input, unknownFields, extensionRegistry, tag, field_name);
                   break;
                 }
                 case 8: {
-                  Start = input.ReadInt32();
+                  result.hasStart |= input.ReadInt32(ref result.start_);
                   break;
                 }
                 case 16: {
-                  End = input.ReadInt32();
+                  result.hasEnd |= input.ReadInt32(ref result.end_);
                   break;
                 }
               }
@@ -1749,41 +1739,31 @@
               if (unknownFields == null) {
                 unknownFields = pb::UnknownFieldSet.CreateBuilder(this.UnknownFields);
               }
-              ParseUnknownField(input, unknownFields, extensionRegistry, tag);
+              ParseUnknownField(input, unknownFields, extensionRegistry, tag, field_name);
               break;
             }
             case 10: {
-              Name = input.ReadString();
+              result.hasName |= input.ReadString(ref result.name_);
               break;
             }
             case 18: {
-              global::Google.ProtocolBuffers.DescriptorProtos.FieldDescriptorProto.Builder subBuilder = global::Google.ProtocolBuffers.DescriptorProtos.FieldDescriptorProto.CreateBuilder();
-              input.ReadMessage(subBuilder, extensionRegistry);
-              AddField(subBuilder.BuildPartial());
+              input.ReadMessageArray(tag, field_name, result.field_, global::Google.ProtocolBuffers.DescriptorProtos.FieldDescriptorProto.DefaultInstance, extensionRegistry);
               break;
             }
             case 26: {
-              global::Google.ProtocolBuffers.DescriptorProtos.DescriptorProto.Builder subBuilder = global::Google.ProtocolBuffers.DescriptorProtos.DescriptorProto.CreateBuilder();
-              input.ReadMessage(subBuilder, extensionRegistry);
-              AddNestedType(subBuilder.BuildPartial());
+              input.ReadMessageArray(tag, field_name, result.nestedType_, global::Google.ProtocolBuffers.DescriptorProtos.DescriptorProto.DefaultInstance, extensionRegistry);
               break;
             }
             case 34: {
-              global::Google.ProtocolBuffers.DescriptorProtos.EnumDescriptorProto.Builder subBuilder = global::Google.ProtocolBuffers.DescriptorProtos.EnumDescriptorProto.CreateBuilder();
-              input.ReadMessage(subBuilder, extensionRegistry);
-              AddEnumType(subBuilder.BuildPartial());
+              input.ReadMessageArray(tag, field_name, result.enumType_, global::Google.ProtocolBuffers.DescriptorProtos.EnumDescriptorProto.DefaultInstance, extensionRegistry);
               break;
             }
             case 42: {
-              global::Google.ProtocolBuffers.DescriptorProtos.DescriptorProto.Types.ExtensionRange.Builder subBuilder = global::Google.ProtocolBuffers.DescriptorProtos.DescriptorProto.Types.ExtensionRange.CreateBuilder();
-              input.ReadMessage(subBuilder, extensionRegistry);
-              AddExtensionRange(subBuilder.BuildPartial());
+              input.ReadMessageArray(tag, field_name, result.extensionRange_, global::Google.ProtocolBuffers.DescriptorProtos.DescriptorProto.Types.ExtensionRange.DefaultInstance, extensionRegistry);
               break;
             }
             case 50: {
-              global::Google.ProtocolBuffers.DescriptorProtos.FieldDescriptorProto.Builder subBuilder = global::Google.ProtocolBuffers.DescriptorProtos.FieldDescriptorProto.CreateBuilder();
-              input.ReadMessage(subBuilder, extensionRegistry);
-              AddExtension(subBuilder.BuildPartial());
+              input.ReadMessageArray(tag, field_name, result.extension_, global::Google.ProtocolBuffers.DescriptorProtos.FieldDescriptorProto.DefaultInstance, extensionRegistry);
               break;
             }
             case 58: {
@@ -2414,51 +2394,51 @@
               if (unknownFields == null) {
                 unknownFields = pb::UnknownFieldSet.CreateBuilder(this.UnknownFields);
               }
-              ParseUnknownField(input, unknownFields, extensionRegistry, tag);
+              ParseUnknownField(input, unknownFields, extensionRegistry, tag, field_name);
               break;
             }
             case 10: {
-              Name = input.ReadString();
+              result.hasName |= input.ReadString(ref result.name_);
               break;
             }
             case 18: {
-              Extendee = input.ReadString();
+              result.hasExtendee |= input.ReadString(ref result.extendee_);
               break;
             }
             case 24: {
-              Number = input.ReadInt32();
+              result.hasNumber |= input.ReadInt32(ref result.number_);
               break;
             }
             case 32: {
-              int rawValue = input.ReadEnum();
-              if (!global::System.Enum.IsDefined(typeof(global::Google.ProtocolBuffers.DescriptorProtos.FieldDescriptorProto.Types.Label), rawValue)) {
+              object unknown;
+              if(input.ReadEnum(ref result.label_, out unknown)) {
+                result.hasLabel = true;
+              } else if(unknown is int) {
                 if (unknownFields == null) {
                   unknownFields = pb::UnknownFieldSet.CreateBuilder(this.UnknownFields);
                 }
-                unknownFields.MergeVarintField(4, (ulong) rawValue);
-              } else {
-                Label = (global::Google.ProtocolBuffers.DescriptorProtos.FieldDescriptorProto.Types.Label) rawValue;
+                unknownFields.MergeVarintField(4, (ulong)(int)unknown);
               }
               break;
             }
             case 40: {
-              int rawValue = input.ReadEnum();
-              if (!global::System.Enum.IsDefined(typeof(global::Google.ProtocolBuffers.DescriptorProtos.FieldDescriptorProto.Types.Type), rawValue)) {
+              object unknown;
+              if(input.ReadEnum(ref result.type_, out unknown)) {
+                result.hasType = true;
+              } else if(unknown is int) {
                 if (unknownFields == null) {
                   unknownFields = pb::UnknownFieldSet.CreateBuilder(this.UnknownFields);
                 }
-                unknownFields.MergeVarintField(5, (ulong) rawValue);
-              } else {
-                Type = (global::Google.ProtocolBuffers.DescriptorProtos.FieldDescriptorProto.Types.Type) rawValue;
+                unknownFields.MergeVarintField(5, (ulong)(int)unknown);
               }
               break;
             }
             case 50: {
-              TypeName = input.ReadString();
+              result.hasTypeName |= input.ReadString(ref result.typeName_);
               break;
             }
             case 58: {
-              DefaultValue = input.ReadString();
+              result.hasDefaultValue |= input.ReadString(ref result.defaultValue_);
               break;
             }
             case 66: {
@@ -2882,17 +2862,15 @@
               if (unknownFields == null) {
                 unknownFields = pb::UnknownFieldSet.CreateBuilder(this.UnknownFields);
               }
-              ParseUnknownField(input, unknownFields, extensionRegistry, tag);
+              ParseUnknownField(input, unknownFields, extensionRegistry, tag, field_name);
               break;
             }
             case 10: {
-              Name = input.ReadString();
+              result.hasName |= input.ReadString(ref result.name_);
               break;
             }
             case 18: {
-              global::Google.ProtocolBuffers.DescriptorProtos.EnumValueDescriptorProto.Builder subBuilder = global::Google.ProtocolBuffers.DescriptorProtos.EnumValueDescriptorProto.CreateBuilder();
-              input.ReadMessage(subBuilder, extensionRegistry);
-              AddValue(subBuilder.BuildPartial());
+              input.ReadMessageArray(tag, field_name, result.value_, global::Google.ProtocolBuffers.DescriptorProtos.EnumValueDescriptorProto.DefaultInstance, extensionRegistry);
               break;
             }
             case 26: {
@@ -3237,15 +3215,15 @@
               if (unknownFields == null) {
                 unknownFields = pb::UnknownFieldSet.CreateBuilder(this.UnknownFields);
               }
-              ParseUnknownField(input, unknownFields, extensionRegistry, tag);
+              ParseUnknownField(input, unknownFields, extensionRegistry, tag, field_name);
               break;
             }
             case 10: {
-              Name = input.ReadString();
+              result.hasName |= input.ReadString(ref result.name_);
               break;
             }
             case 16: {
-              Number = input.ReadInt32();
+              result.hasNumber |= input.ReadInt32(ref result.number_);
               break;
             }
             case 26: {
@@ -3576,17 +3554,15 @@
               if (unknownFields == null) {
                 unknownFields = pb::UnknownFieldSet.CreateBuilder(this.UnknownFields);
               }
-              ParseUnknownField(input, unknownFields, extensionRegistry, tag);
+              ParseUnknownField(input, unknownFields, extensionRegistry, tag, field_name);
               break;
             }
             case 10: {
-              Name = input.ReadString();
+              result.hasName |= input.ReadString(ref result.name_);
               break;
             }
             case 18: {
-              global::Google.ProtocolBuffers.DescriptorProtos.MethodDescriptorProto.Builder subBuilder = global::Google.ProtocolBuffers.DescriptorProtos.MethodDescriptorProto.CreateBuilder();
-              input.ReadMessage(subBuilder, extensionRegistry);
-              AddMethod(subBuilder.BuildPartial());
+              input.ReadMessageArray(tag, field_name, result.method_, global::Google.ProtocolBuffers.DescriptorProtos.MethodDescriptorProto.DefaultInstance, extensionRegistry);
               break;
             }
             case 26: {
@@ -3950,19 +3926,19 @@
               if (unknownFields == null) {
                 unknownFields = pb::UnknownFieldSet.CreateBuilder(this.UnknownFields);
               }
-              ParseUnknownField(input, unknownFields, extensionRegistry, tag);
+              ParseUnknownField(input, unknownFields, extensionRegistry, tag, field_name);
               break;
             }
             case 10: {
-              Name = input.ReadString();
+              result.hasName |= input.ReadString(ref result.name_);
               break;
             }
             case 18: {
-              InputType = input.ReadString();
+              result.hasInputType |= input.ReadString(ref result.inputType_);
               break;
             }
             case 26: {
-              OutputType = input.ReadString();
+              result.hasOutputType |= input.ReadString(ref result.outputType_);
               break;
             }
             case 34: {
@@ -4426,49 +4402,47 @@
               if (unknownFields == null) {
                 unknownFields = pb::UnknownFieldSet.CreateBuilder(this.UnknownFields);
               }
-              ParseUnknownField(input, unknownFields, extensionRegistry, tag);
+              ParseUnknownField(input, unknownFields, extensionRegistry, tag, field_name);
               break;
             }
             case 10: {
-              JavaPackage = input.ReadString();
+              result.hasJavaPackage |= input.ReadString(ref result.javaPackage_);
               break;
             }
             case 66: {
-              JavaOuterClassname = input.ReadString();
+              result.hasJavaOuterClassname |= input.ReadString(ref result.javaOuterClassname_);
               break;
             }
             case 72: {
-              int rawValue = input.ReadEnum();
-              if (!global::System.Enum.IsDefined(typeof(global::Google.ProtocolBuffers.DescriptorProtos.FileOptions.Types.OptimizeMode), rawValue)) {
+              object unknown;
+              if(input.ReadEnum(ref result.optimizeFor_, out unknown)) {
+                result.hasOptimizeFor = true;
+              } else if(unknown is int) {
                 if (unknownFields == null) {
                   unknownFields = pb::UnknownFieldSet.CreateBuilder(this.UnknownFields);
                 }
-                unknownFields.MergeVarintField(9, (ulong) rawValue);
-              } else {
-                OptimizeFor = (global::Google.ProtocolBuffers.DescriptorProtos.FileOptions.Types.OptimizeMode) rawValue;
+                unknownFields.MergeVarintField(9, (ulong)(int)unknown);
               }
               break;
             }
             case 80: {
-              JavaMultipleFiles = input.ReadBool();
+              result.hasJavaMultipleFiles |= input.ReadBool(ref result.javaMultipleFiles_);
               break;
             }
             case 128: {
-              CcGenericServices = input.ReadBool();
+              result.hasCcGenericServices |= input.ReadBool(ref result.ccGenericServices_);
               break;
             }
             case 136: {
-              JavaGenericServices = input.ReadBool();
+              result.hasJavaGenericServices |= input.ReadBool(ref result.javaGenericServices_);
               break;
             }
             case 144: {
-              PyGenericServices = input.ReadBool();
+              result.hasPyGenericServices |= input.ReadBool(ref result.pyGenericServices_);
               break;
             }
             case 7994: {
-              global::Google.ProtocolBuffers.DescriptorProtos.UninterpretedOption.Builder subBuilder = global::Google.ProtocolBuffers.DescriptorProtos.UninterpretedOption.CreateBuilder();
-              input.ReadMessage(subBuilder, extensionRegistry);
-              AddUninterpretedOption(subBuilder.BuildPartial());
+              input.ReadMessageArray(tag, field_name, result.uninterpretedOption_, global::Google.ProtocolBuffers.DescriptorProtos.UninterpretedOption.DefaultInstance, extensionRegistry);
               break;
             }
           }
@@ -4885,21 +4859,19 @@
               if (unknownFields == null) {
                 unknownFields = pb::UnknownFieldSet.CreateBuilder(this.UnknownFields);
               }
-              ParseUnknownField(input, unknownFields, extensionRegistry, tag);
+              ParseUnknownField(input, unknownFields, extensionRegistry, tag, field_name);
               break;
             }
             case 8: {
-              MessageSetWireFormat = input.ReadBool();
+              result.hasMessageSetWireFormat |= input.ReadBool(ref result.messageSetWireFormat_);
               break;
             }
             case 16: {
-              NoStandardDescriptorAccessor = input.ReadBool();
+              result.hasNoStandardDescriptorAccessor |= input.ReadBool(ref result.noStandardDescriptorAccessor_);
               break;
             }
             case 7994: {
-              global::Google.ProtocolBuffers.DescriptorProtos.UninterpretedOption.Builder subBuilder = global::Google.ProtocolBuffers.DescriptorProtos.UninterpretedOption.CreateBuilder();
-              input.ReadMessage(subBuilder, extensionRegistry);
-              AddUninterpretedOption(subBuilder.BuildPartial());
+              input.ReadMessageArray(tag, field_name, result.uninterpretedOption_, global::Google.ProtocolBuffers.DescriptorProtos.UninterpretedOption.DefaultInstance, extensionRegistry);
               break;
             }
           }
@@ -5278,37 +5250,35 @@
               if (unknownFields == null) {
                 unknownFields = pb::UnknownFieldSet.CreateBuilder(this.UnknownFields);
               }
-              ParseUnknownField(input, unknownFields, extensionRegistry, tag);
+              ParseUnknownField(input, unknownFields, extensionRegistry, tag, field_name);
               break;
             }
             case 8: {
-              int rawValue = input.ReadEnum();
-              if (!global::System.Enum.IsDefined(typeof(global::Google.ProtocolBuffers.DescriptorProtos.FieldOptions.Types.CType), rawValue)) {
+              object unknown;
+              if(input.ReadEnum(ref result.ctype_, out unknown)) {
+                result.hasCtype = true;
+              } else if(unknown is int) {
                 if (unknownFields == null) {
                   unknownFields = pb::UnknownFieldSet.CreateBuilder(this.UnknownFields);
                 }
-                unknownFields.MergeVarintField(1, (ulong) rawValue);
-              } else {
-                Ctype = (global::Google.ProtocolBuffers.DescriptorProtos.FieldOptions.Types.CType) rawValue;
+                unknownFields.MergeVarintField(1, (ulong)(int)unknown);
               }
               break;
             }
             case 16: {
-              Packed = input.ReadBool();
+              result.hasPacked |= input.ReadBool(ref result.packed_);
               break;
             }
             case 24: {
-              Deprecated = input.ReadBool();
+              result.hasDeprecated |= input.ReadBool(ref result.deprecated_);
               break;
             }
             case 74: {
-              ExperimentalMapKey = input.ReadString();
+              result.hasExperimentalMapKey |= input.ReadString(ref result.experimentalMapKey_);
               break;
             }
             case 7994: {
-              global::Google.ProtocolBuffers.DescriptorProtos.UninterpretedOption.Builder subBuilder = global::Google.ProtocolBuffers.DescriptorProtos.UninterpretedOption.CreateBuilder();
-              input.ReadMessage(subBuilder, extensionRegistry);
-              AddUninterpretedOption(subBuilder.BuildPartial());
+              input.ReadMessageArray(tag, field_name, result.uninterpretedOption_, global::Google.ProtocolBuffers.DescriptorProtos.UninterpretedOption.DefaultInstance, extensionRegistry);
               break;
             }
           }
@@ -5632,13 +5602,11 @@
               if (unknownFields == null) {
                 unknownFields = pb::UnknownFieldSet.CreateBuilder(this.UnknownFields);
               }
-              ParseUnknownField(input, unknownFields, extensionRegistry, tag);
+              ParseUnknownField(input, unknownFields, extensionRegistry, tag, field_name);
               break;
             }
             case 7994: {
-              global::Google.ProtocolBuffers.DescriptorProtos.UninterpretedOption.Builder subBuilder = global::Google.ProtocolBuffers.DescriptorProtos.UninterpretedOption.CreateBuilder();
-              input.ReadMessage(subBuilder, extensionRegistry);
-              AddUninterpretedOption(subBuilder.BuildPartial());
+              input.ReadMessageArray(tag, field_name, result.uninterpretedOption_, global::Google.ProtocolBuffers.DescriptorProtos.UninterpretedOption.DefaultInstance, extensionRegistry);
               break;
             }
           }
@@ -5889,13 +5857,11 @@
               if (unknownFields == null) {
                 unknownFields = pb::UnknownFieldSet.CreateBuilder(this.UnknownFields);
               }
-              ParseUnknownField(input, unknownFields, extensionRegistry, tag);
+              ParseUnknownField(input, unknownFields, extensionRegistry, tag, field_name);
               break;
             }
             case 7994: {
-              global::Google.ProtocolBuffers.DescriptorProtos.UninterpretedOption.Builder subBuilder = global::Google.ProtocolBuffers.DescriptorProtos.UninterpretedOption.CreateBuilder();
-              input.ReadMessage(subBuilder, extensionRegistry);
-              AddUninterpretedOption(subBuilder.BuildPartial());
+              input.ReadMessageArray(tag, field_name, result.uninterpretedOption_, global::Google.ProtocolBuffers.DescriptorProtos.UninterpretedOption.DefaultInstance, extensionRegistry);
               break;
             }
           }
@@ -6146,13 +6112,11 @@
               if (unknownFields == null) {
                 unknownFields = pb::UnknownFieldSet.CreateBuilder(this.UnknownFields);
               }
-              ParseUnknownField(input, unknownFields, extensionRegistry, tag);
+              ParseUnknownField(input, unknownFields, extensionRegistry, tag, field_name);
               break;
             }
             case 7994: {
-              global::Google.ProtocolBuffers.DescriptorProtos.UninterpretedOption.Builder subBuilder = global::Google.ProtocolBuffers.DescriptorProtos.UninterpretedOption.CreateBuilder();
-              input.ReadMessage(subBuilder, extensionRegistry);
-              AddUninterpretedOption(subBuilder.BuildPartial());
+              input.ReadMessageArray(tag, field_name, result.uninterpretedOption_, global::Google.ProtocolBuffers.DescriptorProtos.UninterpretedOption.DefaultInstance, extensionRegistry);
               break;
             }
           }
@@ -6403,13 +6367,11 @@
               if (unknownFields == null) {
                 unknownFields = pb::UnknownFieldSet.CreateBuilder(this.UnknownFields);
               }
-              ParseUnknownField(input, unknownFields, extensionRegistry, tag);
+              ParseUnknownField(input, unknownFields, extensionRegistry, tag, field_name);
               break;
             }
             case 7994: {
-              global::Google.ProtocolBuffers.DescriptorProtos.UninterpretedOption.Builder subBuilder = global::Google.ProtocolBuffers.DescriptorProtos.UninterpretedOption.CreateBuilder();
-              input.ReadMessage(subBuilder, extensionRegistry);
-              AddUninterpretedOption(subBuilder.BuildPartial());
+              input.ReadMessageArray(tag, field_name, result.uninterpretedOption_, global::Google.ProtocolBuffers.DescriptorProtos.UninterpretedOption.DefaultInstance, extensionRegistry);
               break;
             }
           }
@@ -6700,15 +6662,15 @@
                   if (unknownFields == null) {
                     unknownFields = pb::UnknownFieldSet.CreateBuilder(this.UnknownFields);
                   }
-                  ParseUnknownField(input, unknownFields, extensionRegistry, tag);
+                  ParseUnknownField(input, unknownFields, extensionRegistry, tag, field_name);
                   break;
                 }
                 case 10: {
-                  NamePart_ = input.ReadString();
+                  result.hasNamePart_ |= input.ReadString(ref result.namePart_);
                   break;
                 }
                 case 16: {
-                  IsExtension = input.ReadBool();
+                  result.hasIsExtension |= input.ReadBool(ref result.isExtension_);
                   break;
                 }
               }
@@ -7027,33 +6989,31 @@
               if (unknownFields == null) {
                 unknownFields = pb::UnknownFieldSet.CreateBuilder(this.UnknownFields);
               }
-              ParseUnknownField(input, unknownFields, extensionRegistry, tag);
+              ParseUnknownField(input, unknownFields, extensionRegistry, tag, field_name);
               break;
             }
             case 18: {
-              global::Google.ProtocolBuffers.DescriptorProtos.UninterpretedOption.Types.NamePart.Builder subBuilder = global::Google.ProtocolBuffers.DescriptorProtos.UninterpretedOption.Types.NamePart.CreateBuilder();
-              input.ReadMessage(subBuilder, extensionRegistry);
-              AddName(subBuilder.BuildPartial());
+              input.ReadMessageArray(tag, field_name, result.name_, global::Google.ProtocolBuffers.DescriptorProtos.UninterpretedOption.Types.NamePart.DefaultInstance, extensionRegistry);
               break;
             }
             case 26: {
-              IdentifierValue = input.ReadString();
+              result.hasIdentifierValue |= input.ReadString(ref result.identifierValue_);
               break;
             }
             case 32: {
-              PositiveIntValue = input.ReadUInt64();
+              result.hasPositiveIntValue |= input.ReadUInt64(ref result.positiveIntValue_);
               break;
             }
             case 40: {
-              NegativeIntValue = input.ReadInt64();
+              result.hasNegativeIntValue |= input.ReadInt64(ref result.negativeIntValue_);
               break;
             }
             case 49: {
-              DoubleValue = input.ReadDouble();
+              result.hasDoubleValue |= input.ReadDouble(ref result.doubleValue_);
               break;
             }
             case 58: {
-              StringValue = input.ReadBytes();
+              result.hasStringValue |= input.ReadBytes(ref result.stringValue_);
               break;
             }
           }
diff --git a/src/ProtocolBuffers/Descriptors/EnumDescriptor.cs b/src/ProtocolBuffers/Descriptors/EnumDescriptor.cs
index 80c2bd0..2922190 100644
--- a/src/ProtocolBuffers/Descriptors/EnumDescriptor.cs
+++ b/src/ProtocolBuffers/Descriptors/EnumDescriptor.cs
@@ -98,6 +98,10 @@
         {
             return FindValueByNumber(number);
         }
+        IEnumLite IEnumLiteMap.FindValueByName(string name)
+        {
+            return FindValueByName(name);
+        }
 
         /// <summary>
         /// Finds an enum value by name.
diff --git a/src/ProtocolBuffers/EnumLite.cs b/src/ProtocolBuffers/EnumLite.cs
index 4c2f8b7..35223fc 100644
--- a/src/ProtocolBuffers/EnumLite.cs
+++ b/src/ProtocolBuffers/EnumLite.cs
@@ -70,6 +70,7 @@
     {
         bool IsValidValue(IEnumLite value);
         IEnumLite FindValueByNumber(int number);
+        IEnumLite FindValueByName(string name);
     }
 
     public class EnumLiteMap<TEnum> : IEnumLiteMap<IEnumLite>
@@ -125,6 +126,14 @@
             return items.TryGetValue(number, out val) ? val : null;
         }
 
+        public IEnumLite FindValueByName(string name)
+        {
+            IEnumLite val;
+            if(Enum.IsDefined(typeof(TEnum), name))
+                return items.TryGetValue((int)Enum.Parse(typeof(TEnum), name, false), out val) ? val : null;
+            return null;
+        }
+
         public bool IsValidValue(IEnumLite value)
         {
             return items.ContainsKey(value.Number);
diff --git a/src/ProtocolBuffers/ExtendableBuilder.cs b/src/ProtocolBuffers/ExtendableBuilder.cs
index 532520e..49265f4 100644
--- a/src/ProtocolBuffers/ExtendableBuilder.cs
+++ b/src/ProtocolBuffers/ExtendableBuilder.cs
@@ -131,9 +131,9 @@
         /// <returns>true unless the tag is an end-group tag</returns>
         [CLSCompliant(false)]
         protected override bool ParseUnknownField(CodedInputStream input, UnknownFieldSet.Builder unknownFields,
-                                                  ExtensionRegistry extensionRegistry, uint tag)
+                                                  ExtensionRegistry extensionRegistry, uint tag, string fieldName)
         {
-            return unknownFields.MergeFieldFrom(input, extensionRegistry, this, tag);
+            return unknownFields.MergeFieldFrom(input, extensionRegistry, this, tag, fieldName);
         }
 
         // ---------------------------------------------------------------
diff --git a/src/ProtocolBuffers/ExtendableBuilderLite.cs b/src/ProtocolBuffers/ExtendableBuilderLite.cs
index fc748e6..f9508d4 100644
--- a/src/ProtocolBuffers/ExtendableBuilderLite.cs
+++ b/src/ProtocolBuffers/ExtendableBuilderLite.cs
@@ -134,7 +134,7 @@
         /// <returns>true unless the tag is an end-group tag</returns>
         [CLSCompliant(false)]
         protected override bool ParseUnknownField(CodedInputStream input,
-                                                  ExtensionRegistry extensionRegistry, uint tag)
+                                                  ExtensionRegistry extensionRegistry, uint tag, string fieldName)
         {
             FieldSet extensions = MessageBeingBuilt.Extensions;
 
@@ -142,119 +142,81 @@
             int fieldNumber = WireFormat.GetTagFieldNumber(tag);
             IGeneratedExtensionLite extension = extensionRegistry[DefaultInstanceForType, fieldNumber];
 
-            bool unknown = false;
-            bool packed = false;
-            if (extension == null)
-            {
-                unknown = true; // Unknown field.
-            }
-            else if (wireType ==
-                     FieldMappingAttribute.WireTypeFromFieldType(extension.Descriptor.FieldType, false /* isPacked */))
-            {
-                packed = false; // Normal, unpacked value.
-            }
-            else if (extension.Descriptor.IsRepeated &&
-                     //?? just returns true ?? extension.Descriptor.type.isPackable() &&
-                     wireType ==
-                     FieldMappingAttribute.WireTypeFromFieldType(extension.Descriptor.FieldType, true /* isPacked */))
-            {
-                packed = true; // Packed value.
-            }
-            else
-            {
-                unknown = true; // Wrong wire type.
-            }
-
-            if (unknown)
-            {
-                // Unknown field or wrong wire type.  Skip.
+            if (extension == null)//unknown field
                 return input.SkipField();
-            }
 
-            if (packed)
+            IFieldDescriptorLite field = extension.Descriptor;
+            if (!field.IsRepeated && wireType != WireFormat.GetWireType(field.FieldType)) //invalid wire type
+                return input.SkipField();
+
+            switch (field.FieldType)
             {
-                int length = (int) Math.Min(int.MaxValue, input.ReadRawVarint32());
-                int limit = input.PushLimit(length);
-                if (extension.Descriptor.FieldType == FieldType.Enum)
-                {
-                    while (!input.ReachedLimit)
+                case FieldType.Group:
+                case FieldType.Message:
                     {
-                        int rawValue = input.ReadEnum();
-                        Object value =
-                            extension.Descriptor.EnumType.FindValueByNumber(rawValue);
-                        if (value == null)
+                        if (!field.IsRepeated)
                         {
-                            // If the number isn't recognized as a valid value for this
-                            // enum, drop it (don't even add it to unknownFields).
-                            return true;
-                        }
-                        extensions.AddRepeatedField(extension.Descriptor, value);
-                    }
-                }
-                else
-                {
-                    while (!input.ReachedLimit)
-                    {
-                        Object value = input.ReadPrimitiveField(extension.Descriptor.FieldType);
-                        extensions.AddRepeatedField(extension.Descriptor, value);
-                    }
-                }
-                input.PopLimit(limit);
-            }
-            else
-            {
-                Object value;
-                switch (extension.Descriptor.MappedType)
-                {
-                    case MappedType.Message:
-                        {
-                            IBuilderLite subBuilder = null;
-                            if (!extension.Descriptor.IsRepeated)
-                            {
-                                IMessageLite existingValue = extensions[extension.Descriptor] as IMessageLite;
-                                if (existingValue != null)
-                                {
-                                    subBuilder = existingValue.WeakToBuilder();
-                                }
-                            }
-                            if (subBuilder == null)
-                            {
-                                subBuilder = extension.MessageDefaultInstance.WeakCreateBuilderForType();
-                            }
-                            if (extension.Descriptor.FieldType == FieldType.Group)
-                            {
-                                input.ReadGroup(extension.Number, subBuilder, extensionRegistry);
-                            }
+                            IMessageLite message = extensions[extension.Descriptor] as IMessageLite;
+                            IBuilderLite subBuilder = (message ?? extension.MessageDefaultInstance).WeakToBuilder();
+
+                            if (field.FieldType == FieldType.Group)
+                                input.ReadGroup(field.FieldNumber, subBuilder, extensionRegistry);
                             else
-                            {
                                 input.ReadMessage(subBuilder, extensionRegistry);
-                            }
-                            value = subBuilder.WeakBuild();
-                            break;
+                            
+                            extensions[field] = subBuilder.WeakBuild();
                         }
-                    case MappedType.Enum:
-                        int rawValue = input.ReadEnum();
-                        value = extension.Descriptor.EnumType.FindValueByNumber(rawValue);
-                        // If the number isn't recognized as a valid value for this enum,
-                        // drop it.
-                        if (value == null)
+                        else
                         {
+                            List<IMessageLite> list = new List<IMessageLite>();
+                            if (field.FieldType == FieldType.Group)
+                                input.ReadGroupArray(tag, fieldName, list, extension.MessageDefaultInstance, extensionRegistry);
+                            else
+                                input.ReadMessageArray(tag, fieldName, list, extension.MessageDefaultInstance, extensionRegistry);
+
+                            foreach (IMessageLite m in list)
+                                extensions.AddRepeatedField(field, m);
                             return true;
                         }
                         break;
-                    default:
-                        value = input.ReadPrimitiveField(extension.Descriptor.FieldType);
-                        break;
-                }
+                    }
+                case FieldType.Enum:
+                    {
+                        if (!field.IsRepeated)
+                        {
+                            object unknown;
+                            IEnumLite value = null;
+                            if (input.ReadEnum(ref value, out unknown, field.EnumType))
+                                extensions[field] = value;
+                        }
+                        else
+                        {
+                            ICollection<object> unknown;
+                            List<IEnumLite> list = new List<IEnumLite>();
+                            input.ReadEnumArray(tag, fieldName, list, out unknown, field.EnumType);
 
-                if (extension.Descriptor.IsRepeated)
-                {
-                    extensions.AddRepeatedField(extension.Descriptor, value);
-                }
-                else
-                {
-                    extensions[extension.Descriptor] = value;
-                }
+                            foreach (IEnumLite en in list)
+                                extensions.AddRepeatedField(field, en);
+                        }
+                        break;
+                    }
+                default:
+                    {
+                        if (!field.IsRepeated)
+                        {
+                            object value = null;
+                            if (input.ReadPrimitiveField(field.FieldType, ref value))
+                                extensions[field] = value;
+                        }
+                        else
+                        {
+                            List<object> list = new List<object>();
+                            input.ReadPrimitiveArray(field.FieldType, tag, fieldName, list);
+                            foreach (object oval in list)
+                                extensions.AddRepeatedField(field, oval);
+                        }
+                        break;
+                    }
             }
 
             return true;
diff --git a/src/ProtocolBuffers/GeneratedBuilder.cs b/src/ProtocolBuffers/GeneratedBuilder.cs
index b44cd63..699320a 100644
--- a/src/ProtocolBuffers/GeneratedBuilder.cs
+++ b/src/ProtocolBuffers/GeneratedBuilder.cs
@@ -116,7 +116,7 @@
         /// <returns>true unless the tag is an end-group tag</returns>
         [CLSCompliant(false)]
         protected virtual bool ParseUnknownField(CodedInputStream input, UnknownFieldSet.Builder unknownFields,
-                                                 ExtensionRegistry extensionRegistry, uint tag)
+                                                 ExtensionRegistry extensionRegistry, uint tag, string fieldName)
         {
             return unknownFields.MergeFieldFrom(tag, input);
         }
diff --git a/src/ProtocolBuffers/GeneratedBuilderLite.cs b/src/ProtocolBuffers/GeneratedBuilderLite.cs
index 810324c..2562842 100644
--- a/src/ProtocolBuffers/GeneratedBuilderLite.cs
+++ b/src/ProtocolBuffers/GeneratedBuilderLite.cs
@@ -99,7 +99,7 @@
         /// <returns>true unless the tag is an end-group tag</returns>
         [CLSCompliant(false)]
         protected virtual bool ParseUnknownField(CodedInputStream input,
-                                                 ExtensionRegistry extensionRegistry, uint tag)
+                                                 ExtensionRegistry extensionRegistry, uint tag, string fieldName)
         {
             return input.SkipField();
         }
diff --git a/src/ProtocolBuffers/UnknownFieldSet.cs b/src/ProtocolBuffers/UnknownFieldSet.cs
index ff6a153..e0f1cff 100644
--- a/src/ProtocolBuffers/UnknownFieldSet.cs
+++ b/src/ProtocolBuffers/UnknownFieldSet.cs
@@ -450,14 +450,33 @@
                 switch (WireFormat.GetTagWireType(tag))
                 {
                     case WireFormat.WireType.Varint:
-                        GetFieldBuilder(number).AddVarint(input.ReadUInt64());
-                        return true;
+                        {
+                            ulong uint64 = 0;
+                            if(input.ReadUInt64(ref uint64))
+                                GetFieldBuilder(number).AddVarint(uint64);
+                            return true;
+                        }
+                    case WireFormat.WireType.Fixed32:
+                        {
+                            uint uint32 = 0;
+                            if (input.ReadFixed32(ref uint32))
+                                GetFieldBuilder(number).AddFixed32(uint32);
+                            return true;
+                        }
                     case WireFormat.WireType.Fixed64:
-                        GetFieldBuilder(number).AddFixed64(input.ReadFixed64());
-                        return true;
+                        {
+                            ulong uint64 = 0;
+                            if (input.ReadFixed64(ref uint64))
+                                GetFieldBuilder(number).AddFixed64(uint64);
+                            return true;
+                        }
                     case WireFormat.WireType.LengthDelimited:
-                        GetFieldBuilder(number).AddLengthDelimited(input.ReadBytes());
-                        return true;
+                        {
+                            ByteString bytes = null;
+                            if (input.ReadBytes(ref bytes))
+                                GetFieldBuilder(number).AddLengthDelimited(bytes);
+                            return true;
+                        }
                     case WireFormat.WireType.StartGroup:
                         {
                             Builder subBuilder = CreateBuilder();
@@ -469,9 +488,6 @@
                         }
                     case WireFormat.WireType.EndGroup:
                         return false;
-                    case WireFormat.WireType.Fixed32:
-                        GetFieldBuilder(number).AddFixed32(input.ReadFixed32());
-                        return true;
                     default:
                         throw InvalidProtocolBufferException.InvalidWireType();
                 }
@@ -598,7 +614,7 @@
                         break;
                     }
 
-                    if (!MergeFieldFrom(input, extensionRegistry, builder, tag))
+                    if (!MergeFieldFrom(input, extensionRegistry, builder, tag, name))
                     {
                         // end group tag
                         break;
@@ -616,7 +632,7 @@
             /// <param name="tag">The tag, which should already have been read from the input</param>
             /// <returns>true unless the tag is an end-group tag</returns>
             internal bool MergeFieldFrom(CodedInputStream input,
-                                         ExtensionRegistry extensionRegistry, IBuilder builder, uint tag)
+                                         ExtensionRegistry extensionRegistry, IBuilder builder, uint tag, string fieldName)
             {
                 MessageDescriptor type = builder.DescriptorForType;
                 if (type.Options.MessageSetWireFormat && tag == WireFormat.MessageSetTag.ItemStart)
@@ -655,92 +671,81 @@
                     return MergeFieldFrom(tag, input);
                 }
 
-                if (field.IsPacked)
+                switch (field.FieldType)
                 {
-                    int length = (int) input.ReadRawVarint32();
-                    int limit = input.PushLimit(length);
-                    if (field.FieldType == FieldType.Enum)
-                    {
-                        while (!input.ReachedLimit)
+                    case FieldType.Group:
+                    case FieldType.Message:
                         {
-                            int rawValue = input.ReadEnum();
-                            object value = field.EnumType.FindValueByNumber(rawValue);
-                            if (value == null)
+                            IBuilderLite subBuilder = (defaultFieldInstance != null) ? defaultFieldInstance.WeakCreateBuilderForType() : builder.CreateBuilderForField(field);
+                            if (!field.IsRepeated)
                             {
-                                // If the number isn't recognized as a valid value for this
-                                // enum, drop it (don't even add it to unknownFields).
+                                subBuilder.WeakMergeFrom((IMessageLite)builder[field]);
+                                if (field.FieldType == FieldType.Group)
+                                    input.ReadGroup(field.FieldNumber, subBuilder, extensionRegistry);
+                                else
+                                    input.ReadMessage(subBuilder, extensionRegistry);
+                                builder[field] = subBuilder.WeakBuild();
+                            }
+                            else
+                            {
+                                List<IMessageLite> list = new List<IMessageLite>();
+                                if (field.FieldType == FieldType.Group)
+                                    input.ReadGroupArray(tag, fieldName, list, subBuilder.WeakDefaultInstanceForType, extensionRegistry);
+                                else
+                                    input.ReadMessageArray(tag, fieldName, list, subBuilder.WeakDefaultInstanceForType, extensionRegistry);
+
+                                foreach (IMessageLite m in list)
+                                    builder.WeakAddRepeatedField(field, m);
                                 return true;
                             }
-                            builder.WeakAddRepeatedField(field, value);
-                        }
-                    }
-                    else
-                    {
-                        while (!input.ReachedLimit)
-                        {
-                            Object value = input.ReadPrimitiveField(field.FieldType);
-                            builder.WeakAddRepeatedField(field, value);
-                        }
-                    }
-                    input.PopLimit(limit);
-                }
-                else
-                {
-                    object value;
-                    switch (field.FieldType)
-                    {
-                        case FieldType.Group:
-                        case FieldType.Message:
-                            {
-                                IBuilderLite subBuilder;
-                                if (defaultFieldInstance != null)
-                                {
-                                    subBuilder = defaultFieldInstance.WeakCreateBuilderForType();
-                                }
-                                else
-                                {
-                                    subBuilder = builder.CreateBuilderForField(field);
-                                }
-                                if (!field.IsRepeated)
-                                {
-                                    subBuilder.WeakMergeFrom((IMessageLite) builder[field]);
-                                }
-                                if (field.FieldType == FieldType.Group)
-                                {
-                                    input.ReadGroup(field.FieldNumber, subBuilder, extensionRegistry);
-                                }
-                                else
-                                {
-                                    input.ReadMessage(subBuilder, extensionRegistry);
-                                }
-                                value = subBuilder.WeakBuild();
-                                break;
-                            }
-                        case FieldType.Enum:
-                            {
-                                int rawValue = input.ReadEnum();
-                                value = field.EnumType.FindValueByNumber(rawValue);
-                                // If the number isn't recognized as a valid value for this enum,
-                                // drop it.
-                                if (value == null)
-                                {
-                                    MergeVarintField(fieldNumber, (ulong) rawValue);
-                                    return true;
-                                }
-                                break;
-                            }
-                        default:
-                            value = input.ReadPrimitiveField(field.FieldType);
                             break;
-                    }
-                    if (field.IsRepeated)
-                    {
-                        builder.WeakAddRepeatedField(field, value);
-                    }
-                    else
-                    {
-                        builder[field] = value;
-                    }
+                        }
+                    case FieldType.Enum:
+                        {
+                            if (!field.IsRepeated)
+                            {
+                                object unknown;
+                                IEnumLite value = null;
+                                if (input.ReadEnum(ref value, out unknown, field.EnumType))
+                                    builder[field] = value;
+                                else if(unknown is int)
+                                    MergeVarintField(fieldNumber, (ulong)(int)unknown);
+                            }
+                            else
+                            {
+                                ICollection<object> unknown;
+                                List<IEnumLite> list = new List<IEnumLite>();
+                                input.ReadEnumArray(tag, fieldName, list, out unknown, field.EnumType);
+                                
+                                foreach (IEnumLite en in list)
+                                    builder.WeakAddRepeatedField(field, en);
+
+                                if (unknown != null)
+                                {
+                                    foreach (object oval in unknown)
+                                        if (oval is int)
+                                            MergeVarintField(fieldNumber, (ulong)(int)oval);
+                                }
+                            }
+                            break;
+                        }
+                    default:
+                        {
+                            if (!field.IsRepeated)
+                            {
+                                object value = null;
+                                if (input.ReadPrimitiveField(field.FieldType, ref value))
+                                    builder[field] = value;
+                            }
+                            else
+                            {
+                                List<object> list = new List<object>();
+                                input.ReadPrimitiveArray(field.FieldType, tag, fieldName, list);
+                                foreach (object oval in list)
+                                    builder.WeakAddRepeatedField(field, oval);
+                            }
+                            break;
+                        }
                 }
                 return true;
             }
@@ -787,9 +792,9 @@
 
                     if (tag == WireFormat.MessageSetTag.TypeID)
                     {
-                        typeId = input.ReadInt32();
+                        typeId = 0;
                         // Zero is not a valid type ID.
-                        if (typeId != 0)
+                        if (input.ReadInt32(ref typeId) && typeId != 0)
                         {
                             ExtensionInfo extension = extensionRegistry[type, typeId];
                             if (extension != null)
@@ -824,23 +829,21 @@
                     }
                     else if (tag == WireFormat.MessageSetTag.Message)
                     {
-                        if (typeId == 0)
-                        {
-                            // We haven't seen a type ID yet, so we have to store the raw bytes for now.
-                            rawBytes = input.ReadBytes();
-                        }
-                        else if (subBuilder == null)
-                        {
-                            // We don't know how to parse this.  Ignore it.
-                            MergeField(typeId,
-                                       UnknownField.CreateBuilder().AddLengthDelimited(input.ReadBytes()).Build());
-                        }
-                        else
+                        if(subBuilder != null)
                         {
                             // We already know the type, so we can parse directly from the input
                             // with no copying.  Hooray!
                             input.ReadMessage(subBuilder, extensionRegistry);
                         }
+                        else if (input.ReadBytes(ref rawBytes))
+                        {
+                            if (typeId != 0)
+                            {
+                                // We don't know how to parse this.  Ignore it.
+                                MergeField(typeId,
+                                           UnknownField.CreateBuilder().AddLengthDelimited(rawBytes).Build());
+                            }
+                        }
                     }
                     else
                     {
diff --git a/src/ProtocolBuffersLite.Test/TestProtos/UnitTestExtrasLiteProtoFile.cs b/src/ProtocolBuffersLite.Test/TestProtos/UnitTestExtrasLiteProtoFile.cs
index 4597268..abe47a2 100644
--- a/src/ProtocolBuffersLite.Test/TestProtos/UnitTestExtrasLiteProtoFile.cs
+++ b/src/ProtocolBuffersLite.Test/TestProtos/UnitTestExtrasLiteProtoFile.cs
@@ -258,18 +258,18 @@
               if (pb::WireFormat.IsEndGroupTag(tag)) {
                 return this;
               }
-              ParseUnknownField(input, extensionRegistry, tag);
+              ParseUnknownField(input, extensionRegistry, tag, field_name);
               break;
             }
             case 8: {
-              D = input.ReadInt32();
+              result.hasD |= input.ReadInt32(ref result.d_);
               break;
             }
             case 16: {
-              int rawValue = input.ReadEnum();
-              if (!global::System.Enum.IsDefined(typeof(global::Google.ProtocolBuffers.TestProtos.ExtraEnum), rawValue)) {
-              } else {
-                En = (global::Google.ProtocolBuffers.TestProtos.ExtraEnum) rawValue;
+              object unknown;
+              if(input.ReadEnum(ref result.en_, out unknown)) {
+                result.hasEn = true;
+              } else if(unknown is int) {
               }
               break;
             }
@@ -555,18 +555,18 @@
                   if (pb::WireFormat.IsEndGroupTag(tag)) {
                     return this;
                   }
-                  ParseUnknownField(input, extensionRegistry, tag);
+                  ParseUnknownField(input, extensionRegistry, tag, field_name);
                   break;
                 }
                 case 10: {
-                  Number = input.ReadString();
+                  result.hasNumber |= input.ReadString(ref result.number_);
                   break;
                 }
                 case 16: {
-                  int rawValue = input.ReadEnum();
-                  if (!global::System.Enum.IsDefined(typeof(global::Google.ProtocolBuffers.TestProtos.TestInteropPersonLite.Types.PhoneType), rawValue)) {
-                  } else {
-                    Type = (global::Google.ProtocolBuffers.TestProtos.TestInteropPersonLite.Types.PhoneType) rawValue;
+                  object unknown;
+                  if(input.ReadEnum(ref result.type_, out unknown)) {
+                    result.hasType = true;
+                  } else if(unknown is int) {
                   }
                   break;
                 }
@@ -893,27 +893,27 @@
                   if (pb::WireFormat.IsEndGroupTag(tag)) {
                     return this;
                   }
-                  ParseUnknownField(input, extensionRegistry, tag);
+                  ParseUnknownField(input, extensionRegistry, tag, field_name);
                   break;
                 }
                 case 10: {
-                  Address = input.ReadString();
+                  result.hasAddress |= input.ReadString(ref result.address_);
                   break;
                 }
                 case 18: {
-                  Address2 = input.ReadString();
+                  result.hasAddress2 |= input.ReadString(ref result.address2_);
                   break;
                 }
                 case 26: {
-                  City = input.ReadString();
+                  result.hasCity |= input.ReadString(ref result.city_);
                   break;
                 }
                 case 34: {
-                  State = input.ReadString();
+                  result.hasState |= input.ReadString(ref result.state_);
                   break;
                 }
                 case 45: {
-                  Zip = input.ReadFixed32();
+                  result.hasZip |= input.ReadFixed32(ref result.zip_);
                   break;
                 }
               }
@@ -1341,40 +1341,31 @@
               if (pb::WireFormat.IsEndGroupTag(tag)) {
                 return this;
               }
-              ParseUnknownField(input, extensionRegistry, tag);
+              ParseUnknownField(input, extensionRegistry, tag, field_name);
               break;
             }
             case 10: {
-              Name = input.ReadString();
+              result.hasName |= input.ReadString(ref result.name_);
               break;
             }
             case 16: {
-              Id = input.ReadInt32();
+              result.hasId |= input.ReadInt32(ref result.id_);
               break;
             }
             case 26: {
-              Email = input.ReadString();
+              result.hasEmail |= input.ReadString(ref result.email_);
               break;
             }
             case 34: {
-              global::Google.ProtocolBuffers.TestProtos.TestInteropPersonLite.Types.PhoneNumber.Builder subBuilder = global::Google.ProtocolBuffers.TestProtos.TestInteropPersonLite.Types.PhoneNumber.CreateBuilder();
-              input.ReadMessage(subBuilder, extensionRegistry);
-              AddPhone(subBuilder.BuildPartial());
+              input.ReadMessageArray(tag, field_name, result.phone_, global::Google.ProtocolBuffers.TestProtos.TestInteropPersonLite.Types.PhoneNumber.DefaultInstance, extensionRegistry);
               break;
             }
             case 43: {
-              global::Google.ProtocolBuffers.TestProtos.TestInteropPersonLite.Types.Addresses.Builder subBuilder = global::Google.ProtocolBuffers.TestProtos.TestInteropPersonLite.Types.Addresses.CreateBuilder();
-              input.ReadGroup(5, subBuilder, extensionRegistry);
-              AddAddresses(subBuilder.BuildPartial());
+              input.ReadGroupArray(tag, field_name, result.addresses_, global::Google.ProtocolBuffers.TestProtos.TestInteropPersonLite.Types.Addresses.DefaultInstance, extensionRegistry);
               break;
             }
             case 82: {
-              int length = input.ReadInt32();
-              int limit = input.PushLimit(length);
-              while (!input.ReachedLimit) {
-                AddCodes(input.ReadInt32());
-              }
-              input.PopLimit(limit);
+              input.ReadPrimitiveArray(pbd::FieldType.Int32, tag, field_name, result.codes_);
               break;
             }
           }
@@ -1729,11 +1720,11 @@
               if (pb::WireFormat.IsEndGroupTag(tag)) {
                 return this;
               }
-              ParseUnknownField(input, extensionRegistry, tag);
+              ParseUnknownField(input, extensionRegistry, tag, field_name);
               break;
             }
             case 10: {
-              Number = input.ReadString();
+              result.hasNumber |= input.ReadString(ref result.number_);
               break;
             }
           }
diff --git a/src/ProtocolBuffersLite.Test/TestProtos/UnitTestImportLiteProtoFile.cs b/src/ProtocolBuffersLite.Test/TestProtos/UnitTestImportLiteProtoFile.cs
index 26eb96a..0e890f3 100644
--- a/src/ProtocolBuffersLite.Test/TestProtos/UnitTestImportLiteProtoFile.cs
+++ b/src/ProtocolBuffersLite.Test/TestProtos/UnitTestImportLiteProtoFile.cs
@@ -218,11 +218,11 @@
               if (pb::WireFormat.IsEndGroupTag(tag)) {
                 return this;
               }
-              ParseUnknownField(input, extensionRegistry, tag);
+              ParseUnknownField(input, extensionRegistry, tag, field_name);
               break;
             }
             case 8: {
-              D = input.ReadInt32();
+              result.hasD |= input.ReadInt32(ref result.d_);
               break;
             }
           }
diff --git a/src/ProtocolBuffersLite.Test/TestProtos/UnitTestImportProtoFile.cs b/src/ProtocolBuffersLite.Test/TestProtos/UnitTestImportProtoFile.cs
index d97466d..cbd6cea 100644
--- a/src/ProtocolBuffersLite.Test/TestProtos/UnitTestImportProtoFile.cs
+++ b/src/ProtocolBuffersLite.Test/TestProtos/UnitTestImportProtoFile.cs
@@ -249,11 +249,11 @@
               if (unknownFields == null) {
                 unknownFields = pb::UnknownFieldSet.CreateBuilder(this.UnknownFields);
               }
-              ParseUnknownField(input, unknownFields, extensionRegistry, tag);
+              ParseUnknownField(input, unknownFields, extensionRegistry, tag, field_name);
               break;
             }
             case 8: {
-              D = input.ReadInt32();
+              result.hasD |= input.ReadInt32(ref result.d_);
               break;
             }
           }
diff --git a/src/ProtocolBuffersLite.Test/TestProtos/UnitTestLiteImportNonLiteProtoFile.cs b/src/ProtocolBuffersLite.Test/TestProtos/UnitTestLiteImportNonLiteProtoFile.cs
index 4ff7efb..cc9778f 100644
--- a/src/ProtocolBuffersLite.Test/TestProtos/UnitTestLiteImportNonLiteProtoFile.cs
+++ b/src/ProtocolBuffersLite.Test/TestProtos/UnitTestLiteImportNonLiteProtoFile.cs
@@ -207,7 +207,7 @@
               if (pb::WireFormat.IsEndGroupTag(tag)) {
                 return this;
               }
-              ParseUnknownField(input, extensionRegistry, tag);
+              ParseUnknownField(input, extensionRegistry, tag, field_name);
               break;
             }
             case 10: {
diff --git a/src/ProtocolBuffersLite.Test/TestProtos/UnitTestLiteProtoFile.cs b/src/ProtocolBuffersLite.Test/TestProtos/UnitTestLiteProtoFile.cs
index 5347a8b..c843f3f 100644
--- a/src/ProtocolBuffersLite.Test/TestProtos/UnitTestLiteProtoFile.cs
+++ b/src/ProtocolBuffersLite.Test/TestProtos/UnitTestLiteProtoFile.cs
@@ -1261,11 +1261,11 @@
                   if (pb::WireFormat.IsEndGroupTag(tag)) {
                     return this;
                   }
-                  ParseUnknownField(input, extensionRegistry, tag);
+                  ParseUnknownField(input, extensionRegistry, tag, field_name);
                   break;
                 }
                 case 8: {
-                  Bb = input.ReadInt32();
+                  result.hasBb |= input.ReadInt32(ref result.bb_);
                   break;
                 }
               }
@@ -1479,11 +1479,11 @@
                   if (pb::WireFormat.IsEndGroupTag(tag)) {
                     return this;
                   }
-                  ParseUnknownField(input, extensionRegistry, tag);
+                  ParseUnknownField(input, extensionRegistry, tag, field_name);
                   break;
                 }
                 case 136: {
-                  A = input.ReadInt32();
+                  result.hasA |= input.ReadInt32(ref result.a_);
                   break;
                 }
               }
@@ -1697,11 +1697,11 @@
                   if (pb::WireFormat.IsEndGroupTag(tag)) {
                     return this;
                   }
-                  ParseUnknownField(input, extensionRegistry, tag);
+                  ParseUnknownField(input, extensionRegistry, tag, field_name);
                   break;
                 }
                 case 376: {
-                  A = input.ReadInt32();
+                  result.hasA |= input.ReadInt32(ref result.a_);
                   break;
                 }
               }
@@ -3627,67 +3627,67 @@
               if (pb::WireFormat.IsEndGroupTag(tag)) {
                 return this;
               }
-              ParseUnknownField(input, extensionRegistry, tag);
+              ParseUnknownField(input, extensionRegistry, tag, field_name);
               break;
             }
             case 8: {
-              OptionalInt32 = input.ReadInt32();
+              result.hasOptionalInt32 |= input.ReadInt32(ref result.optionalInt32_);
               break;
             }
             case 16: {
-              OptionalInt64 = input.ReadInt64();
+              result.hasOptionalInt64 |= input.ReadInt64(ref result.optionalInt64_);
               break;
             }
             case 24: {
-              OptionalUint32 = input.ReadUInt32();
+              result.hasOptionalUint32 |= input.ReadUInt32(ref result.optionalUint32_);
               break;
             }
             case 32: {
-              OptionalUint64 = input.ReadUInt64();
+              result.hasOptionalUint64 |= input.ReadUInt64(ref result.optionalUint64_);
               break;
             }
             case 40: {
-              OptionalSint32 = input.ReadSInt32();
+              result.hasOptionalSint32 |= input.ReadSInt32(ref result.optionalSint32_);
               break;
             }
             case 48: {
-              OptionalSint64 = input.ReadSInt64();
+              result.hasOptionalSint64 |= input.ReadSInt64(ref result.optionalSint64_);
               break;
             }
             case 61: {
-              OptionalFixed32 = input.ReadFixed32();
+              result.hasOptionalFixed32 |= input.ReadFixed32(ref result.optionalFixed32_);
               break;
             }
             case 65: {
-              OptionalFixed64 = input.ReadFixed64();
+              result.hasOptionalFixed64 |= input.ReadFixed64(ref result.optionalFixed64_);
               break;
             }
             case 77: {
-              OptionalSfixed32 = input.ReadSFixed32();
+              result.hasOptionalSfixed32 |= input.ReadSFixed32(ref result.optionalSfixed32_);
               break;
             }
             case 81: {
-              OptionalSfixed64 = input.ReadSFixed64();
+              result.hasOptionalSfixed64 |= input.ReadSFixed64(ref result.optionalSfixed64_);
               break;
             }
             case 93: {
-              OptionalFloat = input.ReadFloat();
+              result.hasOptionalFloat |= input.ReadFloat(ref result.optionalFloat_);
               break;
             }
             case 97: {
-              OptionalDouble = input.ReadDouble();
+              result.hasOptionalDouble |= input.ReadDouble(ref result.optionalDouble_);
               break;
             }
             case 104: {
-              OptionalBool = input.ReadBool();
+              result.hasOptionalBool |= input.ReadBool(ref result.optionalBool_);
               break;
             }
             case 114: {
-              OptionalString = input.ReadString();
+              result.hasOptionalString |= input.ReadString(ref result.optionalString_);
               break;
             }
             case 122: {
-              OptionalBytes = input.ReadBytes();
+              result.hasOptionalBytes |= input.ReadBytes(ref result.optionalBytes_);
               break;
             }
             case 131: {
@@ -3727,243 +3727,226 @@
               break;
             }
             case 168: {
-              int rawValue = input.ReadEnum();
-              if (!global::System.Enum.IsDefined(typeof(global::Google.ProtocolBuffers.TestProtos.TestAllTypesLite.Types.NestedEnum), rawValue)) {
-              } else {
-                OptionalNestedEnum = (global::Google.ProtocolBuffers.TestProtos.TestAllTypesLite.Types.NestedEnum) rawValue;
+              object unknown;
+              if(input.ReadEnum(ref result.optionalNestedEnum_, out unknown)) {
+                result.hasOptionalNestedEnum = true;
+              } else if(unknown is int) {
               }
               break;
             }
             case 176: {
-              int rawValue = input.ReadEnum();
-              if (!global::System.Enum.IsDefined(typeof(global::Google.ProtocolBuffers.TestProtos.ForeignEnumLite), rawValue)) {
-              } else {
-                OptionalForeignEnum = (global::Google.ProtocolBuffers.TestProtos.ForeignEnumLite) rawValue;
+              object unknown;
+              if(input.ReadEnum(ref result.optionalForeignEnum_, out unknown)) {
+                result.hasOptionalForeignEnum = true;
+              } else if(unknown is int) {
               }
               break;
             }
             case 184: {
-              int rawValue = input.ReadEnum();
-              if (!global::System.Enum.IsDefined(typeof(global::Google.ProtocolBuffers.TestProtos.ImportEnumLite), rawValue)) {
-              } else {
-                OptionalImportEnum = (global::Google.ProtocolBuffers.TestProtos.ImportEnumLite) rawValue;
+              object unknown;
+              if(input.ReadEnum(ref result.optionalImportEnum_, out unknown)) {
+                result.hasOptionalImportEnum = true;
+              } else if(unknown is int) {
               }
               break;
             }
             case 194: {
-              OptionalStringPiece = input.ReadString();
+              result.hasOptionalStringPiece |= input.ReadString(ref result.optionalStringPiece_);
               break;
             }
             case 202: {
-              OptionalCord = input.ReadString();
+              result.hasOptionalCord |= input.ReadString(ref result.optionalCord_);
               break;
             }
             case 248: {
-              AddRepeatedInt32(input.ReadInt32());
+              input.ReadPrimitiveArray(pbd::FieldType.Int32, tag, field_name, result.repeatedInt32_);
               break;
             }
             case 256: {
-              AddRepeatedInt64(input.ReadInt64());
+              input.ReadPrimitiveArray(pbd::FieldType.Int64, tag, field_name, result.repeatedInt64_);
               break;
             }
             case 264: {
-              AddRepeatedUint32(input.ReadUInt32());
+              input.ReadPrimitiveArray(pbd::FieldType.UInt32, tag, field_name, result.repeatedUint32_);
               break;
             }
             case 272: {
-              AddRepeatedUint64(input.ReadUInt64());
+              input.ReadPrimitiveArray(pbd::FieldType.UInt64, tag, field_name, result.repeatedUint64_);
               break;
             }
             case 280: {
-              AddRepeatedSint32(input.ReadSInt32());
+              input.ReadPrimitiveArray(pbd::FieldType.SInt32, tag, field_name, result.repeatedSint32_);
               break;
             }
             case 288: {
-              AddRepeatedSint64(input.ReadSInt64());
+              input.ReadPrimitiveArray(pbd::FieldType.SInt64, tag, field_name, result.repeatedSint64_);
               break;
             }
             case 301: {
-              AddRepeatedFixed32(input.ReadFixed32());
+              input.ReadPrimitiveArray(pbd::FieldType.Fixed32, tag, field_name, result.repeatedFixed32_);
               break;
             }
             case 305: {
-              AddRepeatedFixed64(input.ReadFixed64());
+              input.ReadPrimitiveArray(pbd::FieldType.Fixed64, tag, field_name, result.repeatedFixed64_);
               break;
             }
             case 317: {
-              AddRepeatedSfixed32(input.ReadSFixed32());
+              input.ReadPrimitiveArray(pbd::FieldType.SFixed32, tag, field_name, result.repeatedSfixed32_);
               break;
             }
             case 321: {
-              AddRepeatedSfixed64(input.ReadSFixed64());
+              input.ReadPrimitiveArray(pbd::FieldType.SFixed64, tag, field_name, result.repeatedSfixed64_);
               break;
             }
             case 333: {
-              AddRepeatedFloat(input.ReadFloat());
+              input.ReadPrimitiveArray(pbd::FieldType.Float, tag, field_name, result.repeatedFloat_);
               break;
             }
             case 337: {
-              AddRepeatedDouble(input.ReadDouble());
+              input.ReadPrimitiveArray(pbd::FieldType.Double, tag, field_name, result.repeatedDouble_);
               break;
             }
             case 344: {
-              AddRepeatedBool(input.ReadBool());
+              input.ReadPrimitiveArray(pbd::FieldType.Bool, tag, field_name, result.repeatedBool_);
               break;
             }
             case 354: {
-              AddRepeatedString(input.ReadString());
+              input.ReadPrimitiveArray(pbd::FieldType.String, tag, field_name, result.repeatedString_);
               break;
             }
             case 362: {
-              AddRepeatedBytes(input.ReadBytes());
+              input.ReadPrimitiveArray(pbd::FieldType.Bytes, tag, field_name, result.repeatedBytes_);
               break;
             }
             case 371: {
-              global::Google.ProtocolBuffers.TestProtos.TestAllTypesLite.Types.RepeatedGroup.Builder subBuilder = global::Google.ProtocolBuffers.TestProtos.TestAllTypesLite.Types.RepeatedGroup.CreateBuilder();
-              input.ReadGroup(46, subBuilder, extensionRegistry);
-              AddRepeatedGroup(subBuilder.BuildPartial());
+              input.ReadGroupArray(tag, field_name, result.repeatedGroup_, global::Google.ProtocolBuffers.TestProtos.TestAllTypesLite.Types.RepeatedGroup.DefaultInstance, extensionRegistry);
               break;
             }
             case 386: {
-              global::Google.ProtocolBuffers.TestProtos.TestAllTypesLite.Types.NestedMessage.Builder subBuilder = global::Google.ProtocolBuffers.TestProtos.TestAllTypesLite.Types.NestedMessage.CreateBuilder();
-              input.ReadMessage(subBuilder, extensionRegistry);
-              AddRepeatedNestedMessage(subBuilder.BuildPartial());
+              input.ReadMessageArray(tag, field_name, result.repeatedNestedMessage_, global::Google.ProtocolBuffers.TestProtos.TestAllTypesLite.Types.NestedMessage.DefaultInstance, extensionRegistry);
               break;
             }
             case 394: {
-              global::Google.ProtocolBuffers.TestProtos.ForeignMessageLite.Builder subBuilder = global::Google.ProtocolBuffers.TestProtos.ForeignMessageLite.CreateBuilder();
-              input.ReadMessage(subBuilder, extensionRegistry);
-              AddRepeatedForeignMessage(subBuilder.BuildPartial());
+              input.ReadMessageArray(tag, field_name, result.repeatedForeignMessage_, global::Google.ProtocolBuffers.TestProtos.ForeignMessageLite.DefaultInstance, extensionRegistry);
               break;
             }
             case 402: {
-              global::Google.ProtocolBuffers.TestProtos.ImportMessageLite.Builder subBuilder = global::Google.ProtocolBuffers.TestProtos.ImportMessageLite.CreateBuilder();
-              input.ReadMessage(subBuilder, extensionRegistry);
-              AddRepeatedImportMessage(subBuilder.BuildPartial());
+              input.ReadMessageArray(tag, field_name, result.repeatedImportMessage_, global::Google.ProtocolBuffers.TestProtos.ImportMessageLite.DefaultInstance, extensionRegistry);
               break;
             }
             case 408: {
-              int rawValue = input.ReadEnum();
-              if (!global::System.Enum.IsDefined(typeof(global::Google.ProtocolBuffers.TestProtos.TestAllTypesLite.Types.NestedEnum), rawValue)) {
-              } else {
-                AddRepeatedNestedEnum((global::Google.ProtocolBuffers.TestProtos.TestAllTypesLite.Types.NestedEnum) rawValue);
-              }
+              scg::ICollection<object> unknownItems;
+              input.ReadEnumArray<global::Google.ProtocolBuffers.TestProtos.TestAllTypesLite.Types.NestedEnum>(tag, field_name, result.repeatedNestedEnum_, out unknownItems);
               break;
             }
             case 416: {
-              int rawValue = input.ReadEnum();
-              if (!global::System.Enum.IsDefined(typeof(global::Google.ProtocolBuffers.TestProtos.ForeignEnumLite), rawValue)) {
-              } else {
-                AddRepeatedForeignEnum((global::Google.ProtocolBuffers.TestProtos.ForeignEnumLite) rawValue);
-              }
+              scg::ICollection<object> unknownItems;
+              input.ReadEnumArray<global::Google.ProtocolBuffers.TestProtos.ForeignEnumLite>(tag, field_name, result.repeatedForeignEnum_, out unknownItems);
               break;
             }
             case 424: {
-              int rawValue = input.ReadEnum();
-              if (!global::System.Enum.IsDefined(typeof(global::Google.ProtocolBuffers.TestProtos.ImportEnumLite), rawValue)) {
-              } else {
-                AddRepeatedImportEnum((global::Google.ProtocolBuffers.TestProtos.ImportEnumLite) rawValue);
-              }
+              scg::ICollection<object> unknownItems;
+              input.ReadEnumArray<global::Google.ProtocolBuffers.TestProtos.ImportEnumLite>(tag, field_name, result.repeatedImportEnum_, out unknownItems);
               break;
             }
             case 434: {
-              AddRepeatedStringPiece(input.ReadString());
+              input.ReadPrimitiveArray(pbd::FieldType.String, tag, field_name, result.repeatedStringPiece_);
               break;
             }
             case 442: {
-              AddRepeatedCord(input.ReadString());
+              input.ReadPrimitiveArray(pbd::FieldType.String, tag, field_name, result.repeatedCord_);
               break;
             }
             case 488: {
-              DefaultInt32 = input.ReadInt32();
+              result.hasDefaultInt32 |= input.ReadInt32(ref result.defaultInt32_);
               break;
             }
             case 496: {
-              DefaultInt64 = input.ReadInt64();
+              result.hasDefaultInt64 |= input.ReadInt64(ref result.defaultInt64_);
               break;
             }
             case 504: {
-              DefaultUint32 = input.ReadUInt32();
+              result.hasDefaultUint32 |= input.ReadUInt32(ref result.defaultUint32_);
               break;
             }
             case 512: {
-              DefaultUint64 = input.ReadUInt64();
+              result.hasDefaultUint64 |= input.ReadUInt64(ref result.defaultUint64_);
               break;
             }
             case 520: {
-              DefaultSint32 = input.ReadSInt32();
+              result.hasDefaultSint32 |= input.ReadSInt32(ref result.defaultSint32_);
               break;
             }
             case 528: {
-              DefaultSint64 = input.ReadSInt64();
+              result.hasDefaultSint64 |= input.ReadSInt64(ref result.defaultSint64_);
               break;
             }
             case 541: {
-              DefaultFixed32 = input.ReadFixed32();
+              result.hasDefaultFixed32 |= input.ReadFixed32(ref result.defaultFixed32_);
               break;
             }
             case 545: {
-              DefaultFixed64 = input.ReadFixed64();
+              result.hasDefaultFixed64 |= input.ReadFixed64(ref result.defaultFixed64_);
               break;
             }
             case 557: {
-              DefaultSfixed32 = input.ReadSFixed32();
+              result.hasDefaultSfixed32 |= input.ReadSFixed32(ref result.defaultSfixed32_);
               break;
             }
             case 561: {
-              DefaultSfixed64 = input.ReadSFixed64();
+              result.hasDefaultSfixed64 |= input.ReadSFixed64(ref result.defaultSfixed64_);
               break;
             }
             case 573: {
-              DefaultFloat = input.ReadFloat();
+              result.hasDefaultFloat |= input.ReadFloat(ref result.defaultFloat_);
               break;
             }
             case 577: {
-              DefaultDouble = input.ReadDouble();
+              result.hasDefaultDouble |= input.ReadDouble(ref result.defaultDouble_);
               break;
             }
             case 584: {
-              DefaultBool = input.ReadBool();
+              result.hasDefaultBool |= input.ReadBool(ref result.defaultBool_);
               break;
             }
             case 594: {
-              DefaultString = input.ReadString();
+              result.hasDefaultString |= input.ReadString(ref result.defaultString_);
               break;
             }
             case 602: {
-              DefaultBytes = input.ReadBytes();
+              result.hasDefaultBytes |= input.ReadBytes(ref result.defaultBytes_);
               break;
             }
             case 648: {
-              int rawValue = input.ReadEnum();
-              if (!global::System.Enum.IsDefined(typeof(global::Google.ProtocolBuffers.TestProtos.TestAllTypesLite.Types.NestedEnum), rawValue)) {
-              } else {
-                DefaultNestedEnum = (global::Google.ProtocolBuffers.TestProtos.TestAllTypesLite.Types.NestedEnum) rawValue;
+              object unknown;
+              if(input.ReadEnum(ref result.defaultNestedEnum_, out unknown)) {
+                result.hasDefaultNestedEnum = true;
+              } else if(unknown is int) {
               }
               break;
             }
             case 656: {
-              int rawValue = input.ReadEnum();
-              if (!global::System.Enum.IsDefined(typeof(global::Google.ProtocolBuffers.TestProtos.ForeignEnumLite), rawValue)) {
-              } else {
-                DefaultForeignEnum = (global::Google.ProtocolBuffers.TestProtos.ForeignEnumLite) rawValue;
+              object unknown;
+              if(input.ReadEnum(ref result.defaultForeignEnum_, out unknown)) {
+                result.hasDefaultForeignEnum = true;
+              } else if(unknown is int) {
               }
               break;
             }
             case 664: {
-              int rawValue = input.ReadEnum();
-              if (!global::System.Enum.IsDefined(typeof(global::Google.ProtocolBuffers.TestProtos.ImportEnumLite), rawValue)) {
-              } else {
-                DefaultImportEnum = (global::Google.ProtocolBuffers.TestProtos.ImportEnumLite) rawValue;
+              object unknown;
+              if(input.ReadEnum(ref result.defaultImportEnum_, out unknown)) {
+                result.hasDefaultImportEnum = true;
+              } else if(unknown is int) {
               }
               break;
             }
             case 674: {
-              DefaultStringPiece = input.ReadString();
+              result.hasDefaultStringPiece |= input.ReadString(ref result.defaultStringPiece_);
               break;
             }
             case 682: {
-              DefaultCord = input.ReadString();
+              result.hasDefaultCord |= input.ReadString(ref result.defaultCord_);
               break;
             }
           }
@@ -5747,11 +5730,11 @@
               if (pb::WireFormat.IsEndGroupTag(tag)) {
                 return this;
               }
-              ParseUnknownField(input, extensionRegistry, tag);
+              ParseUnknownField(input, extensionRegistry, tag, field_name);
               break;
             }
             case 8: {
-              C = input.ReadInt32();
+              result.hasC |= input.ReadInt32(ref result.c_);
               break;
             }
           }
@@ -6456,137 +6439,64 @@
               if (pb::WireFormat.IsEndGroupTag(tag)) {
                 return this;
               }
-              ParseUnknownField(input, extensionRegistry, tag);
+              ParseUnknownField(input, extensionRegistry, tag, field_name);
               break;
             }
             case 722: {
-              int length = input.ReadInt32();
-              int limit = input.PushLimit(length);
-              while (!input.ReachedLimit) {
-                AddPackedInt32(input.ReadInt32());
-              }
-              input.PopLimit(limit);
+              input.ReadPrimitiveArray(pbd::FieldType.Int32, tag, field_name, result.packedInt32_);
               break;
             }
             case 730: {
-              int length = input.ReadInt32();
-              int limit = input.PushLimit(length);
-              while (!input.ReachedLimit) {
-                AddPackedInt64(input.ReadInt64());
-              }
-              input.PopLimit(limit);
+              input.ReadPrimitiveArray(pbd::FieldType.Int64, tag, field_name, result.packedInt64_);
               break;
             }
             case 738: {
-              int length = input.ReadInt32();
-              int limit = input.PushLimit(length);
-              while (!input.ReachedLimit) {
-                AddPackedUint32(input.ReadUInt32());
-              }
-              input.PopLimit(limit);
+              input.ReadPrimitiveArray(pbd::FieldType.UInt32, tag, field_name, result.packedUint32_);
               break;
             }
             case 746: {
-              int length = input.ReadInt32();
-              int limit = input.PushLimit(length);
-              while (!input.ReachedLimit) {
-                AddPackedUint64(input.ReadUInt64());
-              }
-              input.PopLimit(limit);
+              input.ReadPrimitiveArray(pbd::FieldType.UInt64, tag, field_name, result.packedUint64_);
               break;
             }
             case 754: {
-              int length = input.ReadInt32();
-              int limit = input.PushLimit(length);
-              while (!input.ReachedLimit) {
-                AddPackedSint32(input.ReadSInt32());
-              }
-              input.PopLimit(limit);
+              input.ReadPrimitiveArray(pbd::FieldType.SInt32, tag, field_name, result.packedSint32_);
               break;
             }
             case 762: {
-              int length = input.ReadInt32();
-              int limit = input.PushLimit(length);
-              while (!input.ReachedLimit) {
-                AddPackedSint64(input.ReadSInt64());
-              }
-              input.PopLimit(limit);
+              input.ReadPrimitiveArray(pbd::FieldType.SInt64, tag, field_name, result.packedSint64_);
               break;
             }
             case 770: {
-              int length = input.ReadInt32();
-              int limit = input.PushLimit(length);
-              while (!input.ReachedLimit) {
-                AddPackedFixed32(input.ReadFixed32());
-              }
-              input.PopLimit(limit);
+              input.ReadPrimitiveArray(pbd::FieldType.Fixed32, tag, field_name, result.packedFixed32_);
               break;
             }
             case 778: {
-              int length = input.ReadInt32();
-              int limit = input.PushLimit(length);
-              while (!input.ReachedLimit) {
-                AddPackedFixed64(input.ReadFixed64());
-              }
-              input.PopLimit(limit);
+              input.ReadPrimitiveArray(pbd::FieldType.Fixed64, tag, field_name, result.packedFixed64_);
               break;
             }
             case 786: {
-              int length = input.ReadInt32();
-              int limit = input.PushLimit(length);
-              while (!input.ReachedLimit) {
-                AddPackedSfixed32(input.ReadSFixed32());
-              }
-              input.PopLimit(limit);
+              input.ReadPrimitiveArray(pbd::FieldType.SFixed32, tag, field_name, result.packedSfixed32_);
               break;
             }
             case 794: {
-              int length = input.ReadInt32();
-              int limit = input.PushLimit(length);
-              while (!input.ReachedLimit) {
-                AddPackedSfixed64(input.ReadSFixed64());
-              }
-              input.PopLimit(limit);
+              input.ReadPrimitiveArray(pbd::FieldType.SFixed64, tag, field_name, result.packedSfixed64_);
               break;
             }
             case 802: {
-              int length = input.ReadInt32();
-              int limit = input.PushLimit(length);
-              while (!input.ReachedLimit) {
-                AddPackedFloat(input.ReadFloat());
-              }
-              input.PopLimit(limit);
+              input.ReadPrimitiveArray(pbd::FieldType.Float, tag, field_name, result.packedFloat_);
               break;
             }
             case 810: {
-              int length = input.ReadInt32();
-              int limit = input.PushLimit(length);
-              while (!input.ReachedLimit) {
-                AddPackedDouble(input.ReadDouble());
-              }
-              input.PopLimit(limit);
+              input.ReadPrimitiveArray(pbd::FieldType.Double, tag, field_name, result.packedDouble_);
               break;
             }
             case 818: {
-              int length = input.ReadInt32();
-              int limit = input.PushLimit(length);
-              while (!input.ReachedLimit) {
-                AddPackedBool(input.ReadBool());
-              }
-              input.PopLimit(limit);
+              input.ReadPrimitiveArray(pbd::FieldType.Bool, tag, field_name, result.packedBool_);
               break;
             }
             case 826: {
-              int length = input.ReadInt32();
-              int oldLimit = input.PushLimit(length);
-              while (!input.ReachedLimit) {
-                int rawValue = input.ReadEnum();
-                if (!global::System.Enum.IsDefined(typeof(global::Google.ProtocolBuffers.TestProtos.ForeignEnumLite), rawValue)) {
-                } else {
-                  AddPackedEnum((global::Google.ProtocolBuffers.TestProtos.ForeignEnumLite) rawValue);
-                }
-              }
-              input.PopLimit(oldLimit);
+              scg::ICollection<object> unknownItems;
+              input.ReadEnumArray<global::Google.ProtocolBuffers.TestProtos.ForeignEnumLite>(tag, field_name, result.packedEnum_, out unknownItems);
               break;
             }
           }
@@ -7152,7 +7062,7 @@
               if (pb::WireFormat.IsEndGroupTag(tag)) {
                 return this;
               }
-              ParseUnknownField(input, extensionRegistry, tag);
+              ParseUnknownField(input, extensionRegistry, tag, field_name);
               break;
             }
           }
@@ -7348,11 +7258,11 @@
               if (pb::WireFormat.IsEndGroupTag(tag)) {
                 return this;
               }
-              ParseUnknownField(input, extensionRegistry, tag);
+              ParseUnknownField(input, extensionRegistry, tag, field_name);
               break;
             }
             case 136: {
-              A = input.ReadInt32();
+              result.hasA |= input.ReadInt32(ref result.a_);
               break;
             }
           }
@@ -7566,11 +7476,11 @@
               if (pb::WireFormat.IsEndGroupTag(tag)) {
                 return this;
               }
-              ParseUnknownField(input, extensionRegistry, tag);
+              ParseUnknownField(input, extensionRegistry, tag, field_name);
               break;
             }
             case 376: {
-              A = input.ReadInt32();
+              result.hasA |= input.ReadInt32(ref result.a_);
               break;
             }
           }
@@ -7770,7 +7680,7 @@
               if (pb::WireFormat.IsEndGroupTag(tag)) {
                 return this;
               }
-              ParseUnknownField(input, extensionRegistry, tag);
+              ParseUnknownField(input, extensionRegistry, tag, field_name);
               break;
             }
           }
@@ -7946,7 +7856,7 @@
               if (pb::WireFormat.IsEndGroupTag(tag)) {
                 return this;
               }
-              ParseUnknownField(input, extensionRegistry, tag);
+              ParseUnknownField(input, extensionRegistry, tag, field_name);
               break;
             }
           }
@@ -8142,11 +8052,11 @@
               if (pb::WireFormat.IsEndGroupTag(tag)) {
                 return this;
               }
-              ParseUnknownField(input, extensionRegistry, tag);
+              ParseUnknownField(input, extensionRegistry, tag, field_name);
               break;
             }
             case 8: {
-              DeprecatedField = input.ReadInt32();
+              result.hasDeprecatedField |= input.ReadInt32(ref result.deprecatedField_);
               break;
             }
           }
diff --git a/src/ProtocolBuffersLite.Test/TestProtos/UnitTestProtoFile.cs b/src/ProtocolBuffersLite.Test/TestProtos/UnitTestProtoFile.cs
index ce2fbc8..d564a02 100644
--- a/src/ProtocolBuffersLite.Test/TestProtos/UnitTestProtoFile.cs
+++ b/src/ProtocolBuffersLite.Test/TestProtos/UnitTestProtoFile.cs
@@ -1246,11 +1246,11 @@
                   if (unknownFields == null) {
                     unknownFields = pb::UnknownFieldSet.CreateBuilder(this.UnknownFields);
                   }
-                  ParseUnknownField(input, unknownFields, extensionRegistry, tag);
+                  ParseUnknownField(input, unknownFields, extensionRegistry, tag, field_name);
                   break;
                 }
                 case 8: {
-                  Bb = input.ReadInt32();
+                  result.hasBb |= input.ReadInt32(ref result.bb_);
                   break;
                 }
               }
@@ -1470,11 +1470,11 @@
                   if (unknownFields == null) {
                     unknownFields = pb::UnknownFieldSet.CreateBuilder(this.UnknownFields);
                   }
-                  ParseUnknownField(input, unknownFields, extensionRegistry, tag);
+                  ParseUnknownField(input, unknownFields, extensionRegistry, tag, field_name);
                   break;
                 }
                 case 136: {
-                  A = input.ReadInt32();
+                  result.hasA |= input.ReadInt32(ref result.a_);
                   break;
                 }
               }
@@ -1694,11 +1694,11 @@
                   if (unknownFields == null) {
                     unknownFields = pb::UnknownFieldSet.CreateBuilder(this.UnknownFields);
                   }
-                  ParseUnknownField(input, unknownFields, extensionRegistry, tag);
+                  ParseUnknownField(input, unknownFields, extensionRegistry, tag, field_name);
                   break;
                 }
                 case 376: {
-                  A = input.ReadInt32();
+                  result.hasA |= input.ReadInt32(ref result.a_);
                   break;
                 }
               }
@@ -3349,67 +3349,67 @@
               if (unknownFields == null) {
                 unknownFields = pb::UnknownFieldSet.CreateBuilder(this.UnknownFields);
               }
-              ParseUnknownField(input, unknownFields, extensionRegistry, tag);
+              ParseUnknownField(input, unknownFields, extensionRegistry, tag, field_name);
               break;
             }
             case 8: {
-              OptionalInt32 = input.ReadInt32();
+              result.hasOptionalInt32 |= input.ReadInt32(ref result.optionalInt32_);
               break;
             }
             case 16: {
-              OptionalInt64 = input.ReadInt64();
+              result.hasOptionalInt64 |= input.ReadInt64(ref result.optionalInt64_);
               break;
             }
             case 24: {
-              OptionalUint32 = input.ReadUInt32();
+              result.hasOptionalUint32 |= input.ReadUInt32(ref result.optionalUint32_);
               break;
             }
             case 32: {
-              OptionalUint64 = input.ReadUInt64();
+              result.hasOptionalUint64 |= input.ReadUInt64(ref result.optionalUint64_);
               break;
             }
             case 40: {
-              OptionalSint32 = input.ReadSInt32();
+              result.hasOptionalSint32 |= input.ReadSInt32(ref result.optionalSint32_);
               break;
             }
             case 48: {
-              OptionalSint64 = input.ReadSInt64();
+              result.hasOptionalSint64 |= input.ReadSInt64(ref result.optionalSint64_);
               break;
             }
             case 61: {
-              OptionalFixed32 = input.ReadFixed32();
+              result.hasOptionalFixed32 |= input.ReadFixed32(ref result.optionalFixed32_);
               break;
             }
             case 65: {
-              OptionalFixed64 = input.ReadFixed64();
+              result.hasOptionalFixed64 |= input.ReadFixed64(ref result.optionalFixed64_);
               break;
             }
             case 77: {
-              OptionalSfixed32 = input.ReadSFixed32();
+              result.hasOptionalSfixed32 |= input.ReadSFixed32(ref result.optionalSfixed32_);
               break;
             }
             case 81: {
-              OptionalSfixed64 = input.ReadSFixed64();
+              result.hasOptionalSfixed64 |= input.ReadSFixed64(ref result.optionalSfixed64_);
               break;
             }
             case 93: {
-              OptionalFloat = input.ReadFloat();
+              result.hasOptionalFloat |= input.ReadFloat(ref result.optionalFloat_);
               break;
             }
             case 97: {
-              OptionalDouble = input.ReadDouble();
+              result.hasOptionalDouble |= input.ReadDouble(ref result.optionalDouble_);
               break;
             }
             case 104: {
-              OptionalBool = input.ReadBool();
+              result.hasOptionalBool |= input.ReadBool(ref result.optionalBool_);
               break;
             }
             case 114: {
-              OptionalString = input.ReadString();
+              result.hasOptionalString |= input.ReadString(ref result.optionalString_);
               break;
             }
             case 122: {
-              OptionalBytes = input.ReadBytes();
+              result.hasOptionalBytes |= input.ReadBytes(ref result.optionalBytes_);
               break;
             }
             case 131: {
@@ -3449,279 +3449,274 @@
               break;
             }
             case 168: {
-              int rawValue = input.ReadEnum();
-              if (!global::System.Enum.IsDefined(typeof(global::Google.ProtocolBuffers.TestProtos.TestAllTypes.Types.NestedEnum), rawValue)) {
+              object unknown;
+              if(input.ReadEnum(ref result.optionalNestedEnum_, out unknown)) {
+                result.hasOptionalNestedEnum = true;
+              } else if(unknown is int) {
                 if (unknownFields == null) {
                   unknownFields = pb::UnknownFieldSet.CreateBuilder(this.UnknownFields);
                 }
-                unknownFields.MergeVarintField(21, (ulong) rawValue);
-              } else {
-                OptionalNestedEnum = (global::Google.ProtocolBuffers.TestProtos.TestAllTypes.Types.NestedEnum) rawValue;
+                unknownFields.MergeVarintField(21, (ulong)(int)unknown);
               }
               break;
             }
             case 176: {
-              int rawValue = input.ReadEnum();
-              if (!global::System.Enum.IsDefined(typeof(global::Google.ProtocolBuffers.TestProtos.ForeignEnum), rawValue)) {
+              object unknown;
+              if(input.ReadEnum(ref result.optionalForeignEnum_, out unknown)) {
+                result.hasOptionalForeignEnum = true;
+              } else if(unknown is int) {
                 if (unknownFields == null) {
                   unknownFields = pb::UnknownFieldSet.CreateBuilder(this.UnknownFields);
                 }
-                unknownFields.MergeVarintField(22, (ulong) rawValue);
-              } else {
-                OptionalForeignEnum = (global::Google.ProtocolBuffers.TestProtos.ForeignEnum) rawValue;
+                unknownFields.MergeVarintField(22, (ulong)(int)unknown);
               }
               break;
             }
             case 184: {
-              int rawValue = input.ReadEnum();
-              if (!global::System.Enum.IsDefined(typeof(global::Google.ProtocolBuffers.TestProtos.ImportEnum), rawValue)) {
+              object unknown;
+              if(input.ReadEnum(ref result.optionalImportEnum_, out unknown)) {
+                result.hasOptionalImportEnum = true;
+              } else if(unknown is int) {
                 if (unknownFields == null) {
                   unknownFields = pb::UnknownFieldSet.CreateBuilder(this.UnknownFields);
                 }
-                unknownFields.MergeVarintField(23, (ulong) rawValue);
-              } else {
-                OptionalImportEnum = (global::Google.ProtocolBuffers.TestProtos.ImportEnum) rawValue;
+                unknownFields.MergeVarintField(23, (ulong)(int)unknown);
               }
               break;
             }
             case 194: {
-              OptionalStringPiece = input.ReadString();
+              result.hasOptionalStringPiece |= input.ReadString(ref result.optionalStringPiece_);
               break;
             }
             case 202: {
-              OptionalCord = input.ReadString();
+              result.hasOptionalCord |= input.ReadString(ref result.optionalCord_);
               break;
             }
             case 248: {
-              AddRepeatedInt32(input.ReadInt32());
+              input.ReadPrimitiveArray(pbd::FieldType.Int32, tag, field_name, result.repeatedInt32_);
               break;
             }
             case 256: {
-              AddRepeatedInt64(input.ReadInt64());
+              input.ReadPrimitiveArray(pbd::FieldType.Int64, tag, field_name, result.repeatedInt64_);
               break;
             }
             case 264: {
-              AddRepeatedUint32(input.ReadUInt32());
+              input.ReadPrimitiveArray(pbd::FieldType.UInt32, tag, field_name, result.repeatedUint32_);
               break;
             }
             case 272: {
-              AddRepeatedUint64(input.ReadUInt64());
+              input.ReadPrimitiveArray(pbd::FieldType.UInt64, tag, field_name, result.repeatedUint64_);
               break;
             }
             case 280: {
-              AddRepeatedSint32(input.ReadSInt32());
+              input.ReadPrimitiveArray(pbd::FieldType.SInt32, tag, field_name, result.repeatedSint32_);
               break;
             }
             case 288: {
-              AddRepeatedSint64(input.ReadSInt64());
+              input.ReadPrimitiveArray(pbd::FieldType.SInt64, tag, field_name, result.repeatedSint64_);
               break;
             }
             case 301: {
-              AddRepeatedFixed32(input.ReadFixed32());
+              input.ReadPrimitiveArray(pbd::FieldType.Fixed32, tag, field_name, result.repeatedFixed32_);
               break;
             }
             case 305: {
-              AddRepeatedFixed64(input.ReadFixed64());
+              input.ReadPrimitiveArray(pbd::FieldType.Fixed64, tag, field_name, result.repeatedFixed64_);
               break;
             }
             case 317: {
-              AddRepeatedSfixed32(input.ReadSFixed32());
+              input.ReadPrimitiveArray(pbd::FieldType.SFixed32, tag, field_name, result.repeatedSfixed32_);
               break;
             }
             case 321: {
-              AddRepeatedSfixed64(input.ReadSFixed64());
+              input.ReadPrimitiveArray(pbd::FieldType.SFixed64, tag, field_name, result.repeatedSfixed64_);
               break;
             }
             case 333: {
-              AddRepeatedFloat(input.ReadFloat());
+              input.ReadPrimitiveArray(pbd::FieldType.Float, tag, field_name, result.repeatedFloat_);
               break;
             }
             case 337: {
-              AddRepeatedDouble(input.ReadDouble());
+              input.ReadPrimitiveArray(pbd::FieldType.Double, tag, field_name, result.repeatedDouble_);
               break;
             }
             case 344: {
-              AddRepeatedBool(input.ReadBool());
+              input.ReadPrimitiveArray(pbd::FieldType.Bool, tag, field_name, result.repeatedBool_);
               break;
             }
             case 354: {
-              AddRepeatedString(input.ReadString());
+              input.ReadPrimitiveArray(pbd::FieldType.String, tag, field_name, result.repeatedString_);
               break;
             }
             case 362: {
-              AddRepeatedBytes(input.ReadBytes());
+              input.ReadPrimitiveArray(pbd::FieldType.Bytes, tag, field_name, result.repeatedBytes_);
               break;
             }
             case 371: {
-              global::Google.ProtocolBuffers.TestProtos.TestAllTypes.Types.RepeatedGroup.Builder subBuilder = global::Google.ProtocolBuffers.TestProtos.TestAllTypes.Types.RepeatedGroup.CreateBuilder();
-              input.ReadGroup(46, subBuilder, extensionRegistry);
-              AddRepeatedGroup(subBuilder.BuildPartial());
+              input.ReadGroupArray(tag, field_name, result.repeatedGroup_, global::Google.ProtocolBuffers.TestProtos.TestAllTypes.Types.RepeatedGroup.DefaultInstance, extensionRegistry);
               break;
             }
             case 386: {
-              global::Google.ProtocolBuffers.TestProtos.TestAllTypes.Types.NestedMessage.Builder subBuilder = global::Google.ProtocolBuffers.TestProtos.TestAllTypes.Types.NestedMessage.CreateBuilder();
-              input.ReadMessage(subBuilder, extensionRegistry);
-              AddRepeatedNestedMessage(subBuilder.BuildPartial());
+              input.ReadMessageArray(tag, field_name, result.repeatedNestedMessage_, global::Google.ProtocolBuffers.TestProtos.TestAllTypes.Types.NestedMessage.DefaultInstance, extensionRegistry);
               break;
             }
             case 394: {
-              global::Google.ProtocolBuffers.TestProtos.ForeignMessage.Builder subBuilder = global::Google.ProtocolBuffers.TestProtos.ForeignMessage.CreateBuilder();
-              input.ReadMessage(subBuilder, extensionRegistry);
-              AddRepeatedForeignMessage(subBuilder.BuildPartial());
+              input.ReadMessageArray(tag, field_name, result.repeatedForeignMessage_, global::Google.ProtocolBuffers.TestProtos.ForeignMessage.DefaultInstance, extensionRegistry);
               break;
             }
             case 402: {
-              global::Google.ProtocolBuffers.TestProtos.ImportMessage.Builder subBuilder = global::Google.ProtocolBuffers.TestProtos.ImportMessage.CreateBuilder();
-              input.ReadMessage(subBuilder, extensionRegistry);
-              AddRepeatedImportMessage(subBuilder.BuildPartial());
+              input.ReadMessageArray(tag, field_name, result.repeatedImportMessage_, global::Google.ProtocolBuffers.TestProtos.ImportMessage.DefaultInstance, extensionRegistry);
               break;
             }
             case 408: {
-              int rawValue = input.ReadEnum();
-              if (!global::System.Enum.IsDefined(typeof(global::Google.ProtocolBuffers.TestProtos.TestAllTypes.Types.NestedEnum), rawValue)) {
+              scg::ICollection<object> unknownItems;
+              input.ReadEnumArray<global::Google.ProtocolBuffers.TestProtos.TestAllTypes.Types.NestedEnum>(tag, field_name, result.repeatedNestedEnum_, out unknownItems);
+              if (unknownItems != null) {
                 if (unknownFields == null) {
                   unknownFields = pb::UnknownFieldSet.CreateBuilder(this.UnknownFields);
                 }
-                unknownFields.MergeVarintField(51, (ulong) rawValue);
-              } else {
-                AddRepeatedNestedEnum((global::Google.ProtocolBuffers.TestProtos.TestAllTypes.Types.NestedEnum) rawValue);
+                foreach (object rawValue in unknownItems)
+                  if (rawValue is int)
+                    unknownFields.MergeVarintField(51, (ulong)(int)rawValue);
               }
               break;
             }
             case 416: {
-              int rawValue = input.ReadEnum();
-              if (!global::System.Enum.IsDefined(typeof(global::Google.ProtocolBuffers.TestProtos.ForeignEnum), rawValue)) {
+              scg::ICollection<object> unknownItems;
+              input.ReadEnumArray<global::Google.ProtocolBuffers.TestProtos.ForeignEnum>(tag, field_name, result.repeatedForeignEnum_, out unknownItems);
+              if (unknownItems != null) {
                 if (unknownFields == null) {
                   unknownFields = pb::UnknownFieldSet.CreateBuilder(this.UnknownFields);
                 }
-                unknownFields.MergeVarintField(52, (ulong) rawValue);
-              } else {
-                AddRepeatedForeignEnum((global::Google.ProtocolBuffers.TestProtos.ForeignEnum) rawValue);
+                foreach (object rawValue in unknownItems)
+                  if (rawValue is int)
+                    unknownFields.MergeVarintField(52, (ulong)(int)rawValue);
               }
               break;
             }
             case 424: {
-              int rawValue = input.ReadEnum();
-              if (!global::System.Enum.IsDefined(typeof(global::Google.ProtocolBuffers.TestProtos.ImportEnum), rawValue)) {
+              scg::ICollection<object> unknownItems;
+              input.ReadEnumArray<global::Google.ProtocolBuffers.TestProtos.ImportEnum>(tag, field_name, result.repeatedImportEnum_, out unknownItems);
+              if (unknownItems != null) {
                 if (unknownFields == null) {
                   unknownFields = pb::UnknownFieldSet.CreateBuilder(this.UnknownFields);
                 }
-                unknownFields.MergeVarintField(53, (ulong) rawValue);
-              } else {
-                AddRepeatedImportEnum((global::Google.ProtocolBuffers.TestProtos.ImportEnum) rawValue);
+                foreach (object rawValue in unknownItems)
+                  if (rawValue is int)
+                    unknownFields.MergeVarintField(53, (ulong)(int)rawValue);
               }
               break;
             }
             case 434: {
-              AddRepeatedStringPiece(input.ReadString());
+              input.ReadPrimitiveArray(pbd::FieldType.String, tag, field_name, result.repeatedStringPiece_);
               break;
             }
             case 442: {
-              AddRepeatedCord(input.ReadString());
+              input.ReadPrimitiveArray(pbd::FieldType.String, tag, field_name, result.repeatedCord_);
               break;
             }
             case 488: {
-              DefaultInt32 = input.ReadInt32();
+              result.hasDefaultInt32 |= input.ReadInt32(ref result.defaultInt32_);
               break;
             }
             case 496: {
-              DefaultInt64 = input.ReadInt64();
+              result.hasDefaultInt64 |= input.ReadInt64(ref result.defaultInt64_);
               break;
             }
             case 504: {
-              DefaultUint32 = input.ReadUInt32();
+              result.hasDefaultUint32 |= input.ReadUInt32(ref result.defaultUint32_);
               break;
             }
             case 512: {
-              DefaultUint64 = input.ReadUInt64();
+              result.hasDefaultUint64 |= input.ReadUInt64(ref result.defaultUint64_);
               break;
             }
             case 520: {
-              DefaultSint32 = input.ReadSInt32();
+              result.hasDefaultSint32 |= input.ReadSInt32(ref result.defaultSint32_);
               break;
             }
             case 528: {
-              DefaultSint64 = input.ReadSInt64();
+              result.hasDefaultSint64 |= input.ReadSInt64(ref result.defaultSint64_);
               break;
             }
             case 541: {
-              DefaultFixed32 = input.ReadFixed32();
+              result.hasDefaultFixed32 |= input.ReadFixed32(ref result.defaultFixed32_);
               break;
             }
             case 545: {
-              DefaultFixed64 = input.ReadFixed64();
+              result.hasDefaultFixed64 |= input.ReadFixed64(ref result.defaultFixed64_);
               break;
             }
             case 557: {
-              DefaultSfixed32 = input.ReadSFixed32();
+              result.hasDefaultSfixed32 |= input.ReadSFixed32(ref result.defaultSfixed32_);
               break;
             }
             case 561: {
-              DefaultSfixed64 = input.ReadSFixed64();
+              result.hasDefaultSfixed64 |= input.ReadSFixed64(ref result.defaultSfixed64_);
               break;
             }
             case 573: {
-              DefaultFloat = input.ReadFloat();
+              result.hasDefaultFloat |= input.ReadFloat(ref result.defaultFloat_);
               break;
             }
             case 577: {
-              DefaultDouble = input.ReadDouble();
+              result.hasDefaultDouble |= input.ReadDouble(ref result.defaultDouble_);
               break;
             }
             case 584: {
-              DefaultBool = input.ReadBool();
+              result.hasDefaultBool |= input.ReadBool(ref result.defaultBool_);
               break;
             }
             case 594: {
-              DefaultString = input.ReadString();
+              result.hasDefaultString |= input.ReadString(ref result.defaultString_);
               break;
             }
             case 602: {
-              DefaultBytes = input.ReadBytes();
+              result.hasDefaultBytes |= input.ReadBytes(ref result.defaultBytes_);
               break;
             }
             case 648: {
-              int rawValue = input.ReadEnum();
-              if (!global::System.Enum.IsDefined(typeof(global::Google.ProtocolBuffers.TestProtos.TestAllTypes.Types.NestedEnum), rawValue)) {
+              object unknown;
+              if(input.ReadEnum(ref result.defaultNestedEnum_, out unknown)) {
+                result.hasDefaultNestedEnum = true;
+              } else if(unknown is int) {
                 if (unknownFields == null) {
                   unknownFields = pb::UnknownFieldSet.CreateBuilder(this.UnknownFields);
                 }
-                unknownFields.MergeVarintField(81, (ulong) rawValue);
-              } else {
-                DefaultNestedEnum = (global::Google.ProtocolBuffers.TestProtos.TestAllTypes.Types.NestedEnum) rawValue;
+                unknownFields.MergeVarintField(81, (ulong)(int)unknown);
               }
               break;
             }
             case 656: {
-              int rawValue = input.ReadEnum();
-              if (!global::System.Enum.IsDefined(typeof(global::Google.ProtocolBuffers.TestProtos.ForeignEnum), rawValue)) {
+              object unknown;
+              if(input.ReadEnum(ref result.defaultForeignEnum_, out unknown)) {
+                result.hasDefaultForeignEnum = true;
+              } else if(unknown is int) {
                 if (unknownFields == null) {
                   unknownFields = pb::UnknownFieldSet.CreateBuilder(this.UnknownFields);
                 }
-                unknownFields.MergeVarintField(82, (ulong) rawValue);
-              } else {
-                DefaultForeignEnum = (global::Google.ProtocolBuffers.TestProtos.ForeignEnum) rawValue;
+                unknownFields.MergeVarintField(82, (ulong)(int)unknown);
               }
               break;
             }
             case 664: {
-              int rawValue = input.ReadEnum();
-              if (!global::System.Enum.IsDefined(typeof(global::Google.ProtocolBuffers.TestProtos.ImportEnum), rawValue)) {
+              object unknown;
+              if(input.ReadEnum(ref result.defaultImportEnum_, out unknown)) {
+                result.hasDefaultImportEnum = true;
+              } else if(unknown is int) {
                 if (unknownFields == null) {
                   unknownFields = pb::UnknownFieldSet.CreateBuilder(this.UnknownFields);
                 }
-                unknownFields.MergeVarintField(83, (ulong) rawValue);
-              } else {
-                DefaultImportEnum = (global::Google.ProtocolBuffers.TestProtos.ImportEnum) rawValue;
+                unknownFields.MergeVarintField(83, (ulong)(int)unknown);
               }
               break;
             }
             case 674: {
-              DefaultStringPiece = input.ReadString();
+              result.hasDefaultStringPiece |= input.ReadString(ref result.defaultStringPiece_);
               break;
             }
             case 682: {
-              DefaultCord = input.ReadString();
+              result.hasDefaultCord |= input.ReadString(ref result.defaultCord_);
               break;
             }
           }
@@ -5511,11 +5506,11 @@
               if (unknownFields == null) {
                 unknownFields = pb::UnknownFieldSet.CreateBuilder(this.UnknownFields);
               }
-              ParseUnknownField(input, unknownFields, extensionRegistry, tag);
+              ParseUnknownField(input, unknownFields, extensionRegistry, tag, field_name);
               break;
             }
             case 8: {
-              DeprecatedInt32 = input.ReadInt32();
+              result.hasDeprecatedInt32 |= input.ReadInt32(ref result.deprecatedInt32_);
               break;
             }
           }
@@ -5735,11 +5730,11 @@
               if (unknownFields == null) {
                 unknownFields = pb::UnknownFieldSet.CreateBuilder(this.UnknownFields);
               }
-              ParseUnknownField(input, unknownFields, extensionRegistry, tag);
+              ParseUnknownField(input, unknownFields, extensionRegistry, tag, field_name);
               break;
             }
             case 8: {
-              C = input.ReadInt32();
+              result.hasC |= input.ReadInt32(ref result.c_);
               break;
             }
           }
@@ -5945,7 +5940,7 @@
               if (unknownFields == null) {
                 unknownFields = pb::UnknownFieldSet.CreateBuilder(this.UnknownFields);
               }
-              ParseUnknownField(input, unknownFields, extensionRegistry, tag);
+              ParseUnknownField(input, unknownFields, extensionRegistry, tag, field_name);
               break;
             }
           }
@@ -6147,11 +6142,11 @@
               if (unknownFields == null) {
                 unknownFields = pb::UnknownFieldSet.CreateBuilder(this.UnknownFields);
               }
-              ParseUnknownField(input, unknownFields, extensionRegistry, tag);
+              ParseUnknownField(input, unknownFields, extensionRegistry, tag, field_name);
               break;
             }
             case 136: {
-              A = input.ReadInt32();
+              result.hasA |= input.ReadInt32(ref result.a_);
               break;
             }
           }
@@ -6371,11 +6366,11 @@
               if (unknownFields == null) {
                 unknownFields = pb::UnknownFieldSet.CreateBuilder(this.UnknownFields);
               }
-              ParseUnknownField(input, unknownFields, extensionRegistry, tag);
+              ParseUnknownField(input, unknownFields, extensionRegistry, tag, field_name);
               break;
             }
             case 376: {
-              A = input.ReadInt32();
+              result.hasA |= input.ReadInt32(ref result.a_);
               break;
             }
           }
@@ -6578,7 +6573,7 @@
               if (unknownFields == null) {
                 unknownFields = pb::UnknownFieldSet.CreateBuilder(this.UnknownFields);
               }
-              ParseUnknownField(input, unknownFields, extensionRegistry, tag);
+              ParseUnknownField(input, unknownFields, extensionRegistry, tag, field_name);
               break;
             }
           }
@@ -7395,139 +7390,139 @@
               if (unknownFields == null) {
                 unknownFields = pb::UnknownFieldSet.CreateBuilder(this.UnknownFields);
               }
-              ParseUnknownField(input, unknownFields, extensionRegistry, tag);
+              ParseUnknownField(input, unknownFields, extensionRegistry, tag, field_name);
               break;
             }
             case 8: {
-              A = input.ReadInt32();
+              result.hasA |= input.ReadInt32(ref result.a_);
               break;
             }
             case 16: {
-              Dummy2 = input.ReadInt32();
+              result.hasDummy2 |= input.ReadInt32(ref result.dummy2_);
               break;
             }
             case 24: {
-              B = input.ReadInt32();
+              result.hasB |= input.ReadInt32(ref result.b_);
               break;
             }
             case 32: {
-              Dummy4 = input.ReadInt32();
+              result.hasDummy4 |= input.ReadInt32(ref result.dummy4_);
               break;
             }
             case 40: {
-              Dummy5 = input.ReadInt32();
+              result.hasDummy5 |= input.ReadInt32(ref result.dummy5_);
               break;
             }
             case 48: {
-              Dummy6 = input.ReadInt32();
+              result.hasDummy6 |= input.ReadInt32(ref result.dummy6_);
               break;
             }
             case 56: {
-              Dummy7 = input.ReadInt32();
+              result.hasDummy7 |= input.ReadInt32(ref result.dummy7_);
               break;
             }
             case 64: {
-              Dummy8 = input.ReadInt32();
+              result.hasDummy8 |= input.ReadInt32(ref result.dummy8_);
               break;
             }
             case 72: {
-              Dummy9 = input.ReadInt32();
+              result.hasDummy9 |= input.ReadInt32(ref result.dummy9_);
               break;
             }
             case 80: {
-              Dummy10 = input.ReadInt32();
+              result.hasDummy10 |= input.ReadInt32(ref result.dummy10_);
               break;
             }
             case 88: {
-              Dummy11 = input.ReadInt32();
+              result.hasDummy11 |= input.ReadInt32(ref result.dummy11_);
               break;
             }
             case 96: {
-              Dummy12 = input.ReadInt32();
+              result.hasDummy12 |= input.ReadInt32(ref result.dummy12_);
               break;
             }
             case 104: {
-              Dummy13 = input.ReadInt32();
+              result.hasDummy13 |= input.ReadInt32(ref result.dummy13_);
               break;
             }
             case 112: {
-              Dummy14 = input.ReadInt32();
+              result.hasDummy14 |= input.ReadInt32(ref result.dummy14_);
               break;
             }
             case 120: {
-              Dummy15 = input.ReadInt32();
+              result.hasDummy15 |= input.ReadInt32(ref result.dummy15_);
               break;
             }
             case 128: {
-              Dummy16 = input.ReadInt32();
+              result.hasDummy16 |= input.ReadInt32(ref result.dummy16_);
               break;
             }
             case 136: {
-              Dummy17 = input.ReadInt32();
+              result.hasDummy17 |= input.ReadInt32(ref result.dummy17_);
               break;
             }
             case 144: {
-              Dummy18 = input.ReadInt32();
+              result.hasDummy18 |= input.ReadInt32(ref result.dummy18_);
               break;
             }
             case 152: {
-              Dummy19 = input.ReadInt32();
+              result.hasDummy19 |= input.ReadInt32(ref result.dummy19_);
               break;
             }
             case 160: {
-              Dummy20 = input.ReadInt32();
+              result.hasDummy20 |= input.ReadInt32(ref result.dummy20_);
               break;
             }
             case 168: {
-              Dummy21 = input.ReadInt32();
+              result.hasDummy21 |= input.ReadInt32(ref result.dummy21_);
               break;
             }
             case 176: {
-              Dummy22 = input.ReadInt32();
+              result.hasDummy22 |= input.ReadInt32(ref result.dummy22_);
               break;
             }
             case 184: {
-              Dummy23 = input.ReadInt32();
+              result.hasDummy23 |= input.ReadInt32(ref result.dummy23_);
               break;
             }
             case 192: {
-              Dummy24 = input.ReadInt32();
+              result.hasDummy24 |= input.ReadInt32(ref result.dummy24_);
               break;
             }
             case 200: {
-              Dummy25 = input.ReadInt32();
+              result.hasDummy25 |= input.ReadInt32(ref result.dummy25_);
               break;
             }
             case 208: {
-              Dummy26 = input.ReadInt32();
+              result.hasDummy26 |= input.ReadInt32(ref result.dummy26_);
               break;
             }
             case 216: {
-              Dummy27 = input.ReadInt32();
+              result.hasDummy27 |= input.ReadInt32(ref result.dummy27_);
               break;
             }
             case 224: {
-              Dummy28 = input.ReadInt32();
+              result.hasDummy28 |= input.ReadInt32(ref result.dummy28_);
               break;
             }
             case 232: {
-              Dummy29 = input.ReadInt32();
+              result.hasDummy29 |= input.ReadInt32(ref result.dummy29_);
               break;
             }
             case 240: {
-              Dummy30 = input.ReadInt32();
+              result.hasDummy30 |= input.ReadInt32(ref result.dummy30_);
               break;
             }
             case 248: {
-              Dummy31 = input.ReadInt32();
+              result.hasDummy31 |= input.ReadInt32(ref result.dummy31_);
               break;
             }
             case 256: {
-              Dummy32 = input.ReadInt32();
+              result.hasDummy32 |= input.ReadInt32(ref result.dummy32_);
               break;
             }
             case 264: {
-              C = input.ReadInt32();
+              result.hasC |= input.ReadInt32(ref result.c_);
               break;
             }
           }
@@ -8370,7 +8365,7 @@
               if (unknownFields == null) {
                 unknownFields = pb::UnknownFieldSet.CreateBuilder(this.UnknownFields);
               }
-              ParseUnknownField(input, unknownFields, extensionRegistry, tag);
+              ParseUnknownField(input, unknownFields, extensionRegistry, tag, field_name);
               break;
             }
             case 10: {
@@ -8383,13 +8378,11 @@
               break;
             }
             case 18: {
-              global::Google.ProtocolBuffers.TestProtos.TestRequired.Builder subBuilder = global::Google.ProtocolBuffers.TestProtos.TestRequired.CreateBuilder();
-              input.ReadMessage(subBuilder, extensionRegistry);
-              AddRepeatedMessage(subBuilder.BuildPartial());
+              input.ReadMessageArray(tag, field_name, result.repeatedMessage_, global::Google.ProtocolBuffers.TestProtos.TestRequired.DefaultInstance, extensionRegistry);
               break;
             }
             case 24: {
-              Dummy = input.ReadInt32();
+              result.hasDummy |= input.ReadInt32(ref result.dummy_);
               break;
             }
           }
@@ -8683,7 +8676,7 @@
               if (unknownFields == null) {
                 unknownFields = pb::UnknownFieldSet.CreateBuilder(this.UnknownFields);
               }
-              ParseUnknownField(input, unknownFields, extensionRegistry, tag);
+              ParseUnknownField(input, unknownFields, extensionRegistry, tag, field_name);
               break;
             }
             case 10: {
@@ -8911,7 +8904,7 @@
               if (unknownFields == null) {
                 unknownFields = pb::UnknownFieldSet.CreateBuilder(this.UnknownFields);
               }
-              ParseUnknownField(input, unknownFields, extensionRegistry, tag);
+              ParseUnknownField(input, unknownFields, extensionRegistry, tag, field_name);
               break;
             }
           }
@@ -9099,7 +9092,7 @@
               if (unknownFields == null) {
                 unknownFields = pb::UnknownFieldSet.CreateBuilder(this.UnknownFields);
               }
-              ParseUnknownField(input, unknownFields, extensionRegistry, tag);
+              ParseUnknownField(input, unknownFields, extensionRegistry, tag, field_name);
               break;
             }
           }
@@ -9289,7 +9282,7 @@
               if (unknownFields == null) {
                 unknownFields = pb::UnknownFieldSet.CreateBuilder(this.UnknownFields);
               }
-              ParseUnknownField(input, unknownFields, extensionRegistry, tag);
+              ParseUnknownField(input, unknownFields, extensionRegistry, tag, field_name);
               break;
             }
           }
@@ -9510,15 +9503,15 @@
               if (unknownFields == null) {
                 unknownFields = pb::UnknownFieldSet.CreateBuilder(this.UnknownFields);
               }
-              ParseUnknownField(input, unknownFields, extensionRegistry, tag);
+              ParseUnknownField(input, unknownFields, extensionRegistry, tag, field_name);
               break;
             }
             case 8: {
-              A = input.ReadInt32();
+              result.hasA |= input.ReadInt32(ref result.a_);
               break;
             }
             case 2147483640: {
-              Bb = input.ReadInt32();
+              result.hasBb |= input.ReadInt32(ref result.bb_);
               break;
             }
           }
@@ -9775,7 +9768,7 @@
               if (unknownFields == null) {
                 unknownFields = pb::UnknownFieldSet.CreateBuilder(this.UnknownFields);
               }
-              ParseUnknownField(input, unknownFields, extensionRegistry, tag);
+              ParseUnknownField(input, unknownFields, extensionRegistry, tag, field_name);
               break;
             }
             case 10: {
@@ -9788,7 +9781,7 @@
               break;
             }
             case 16: {
-              I = input.ReadInt32();
+              result.hasI |= input.ReadInt32(ref result.i_);
               break;
             }
           }
@@ -10044,7 +10037,7 @@
               if (unknownFields == null) {
                 unknownFields = pb::UnknownFieldSet.CreateBuilder(this.UnknownFields);
               }
-              ParseUnknownField(input, unknownFields, extensionRegistry, tag);
+              ParseUnknownField(input, unknownFields, extensionRegistry, tag, field_name);
               break;
             }
             case 10: {
@@ -10310,7 +10303,7 @@
               if (unknownFields == null) {
                 unknownFields = pb::UnknownFieldSet.CreateBuilder(this.UnknownFields);
               }
-              ParseUnknownField(input, unknownFields, extensionRegistry, tag);
+              ParseUnknownField(input, unknownFields, extensionRegistry, tag, field_name);
               break;
             }
             case 10: {
@@ -10323,7 +10316,7 @@
               break;
             }
             case 16: {
-              OptionalInt32 = input.ReadInt32();
+              result.hasOptionalInt32 |= input.ReadInt32(ref result.optionalInt32_);
               break;
             }
           }
@@ -10609,11 +10602,11 @@
                   if (unknownFields == null) {
                     unknownFields = pb::UnknownFieldSet.CreateBuilder(this.UnknownFields);
                   }
-                  ParseUnknownField(input, unknownFields, extensionRegistry, tag);
+                  ParseUnknownField(input, unknownFields, extensionRegistry, tag, field_name);
                   break;
                 }
                 case 8: {
-                  A = input.ReadInt32();
+                  result.hasA |= input.ReadInt32(ref result.a_);
                   break;
                 }
               }
@@ -10833,11 +10826,11 @@
                   if (unknownFields == null) {
                     unknownFields = pb::UnknownFieldSet.CreateBuilder(this.UnknownFields);
                   }
-                  ParseUnknownField(input, unknownFields, extensionRegistry, tag);
+                  ParseUnknownField(input, unknownFields, extensionRegistry, tag, field_name);
                   break;
                 }
                 case 8: {
-                  A = input.ReadInt32();
+                  result.hasA |= input.ReadInt32(ref result.a_);
                   break;
                 }
               }
@@ -11073,11 +11066,11 @@
               if (unknownFields == null) {
                 unknownFields = pb::UnknownFieldSet.CreateBuilder(this.UnknownFields);
               }
-              ParseUnknownField(input, unknownFields, extensionRegistry, tag);
+              ParseUnknownField(input, unknownFields, extensionRegistry, tag, field_name);
               break;
             }
             case 8: {
-              A = input.ReadInt32();
+              result.hasA |= input.ReadInt32(ref result.a_);
               break;
             }
             case 19: {
@@ -11447,17 +11440,15 @@
                   if (unknownFields == null) {
                     unknownFields = pb::UnknownFieldSet.CreateBuilder(this.UnknownFields);
                   }
-                  ParseUnknownField(input, unknownFields, extensionRegistry, tag);
+                  ParseUnknownField(input, unknownFields, extensionRegistry, tag, field_name);
                   break;
                 }
                 case 8: {
-                  AddNestedmessageRepeatedInt32(input.ReadInt32());
+                  input.ReadPrimitiveArray(pbd::FieldType.Int32, tag, field_name, result.nestedmessageRepeatedInt32_);
                   break;
                 }
                 case 18: {
-                  global::Google.ProtocolBuffers.TestProtos.ForeignMessage.Builder subBuilder = global::Google.ProtocolBuffers.TestProtos.ForeignMessage.CreateBuilder();
-                  input.ReadMessage(subBuilder, extensionRegistry);
-                  AddNestedmessageRepeatedForeignmessage(subBuilder.BuildPartial());
+                  input.ReadMessageArray(tag, field_name, result.nestedmessageRepeatedForeignmessage_, global::Google.ProtocolBuffers.TestProtos.ForeignMessage.DefaultInstance, extensionRegistry);
                   break;
                 }
               }
@@ -11701,7 +11692,7 @@
               if (unknownFields == null) {
                 unknownFields = pb::UnknownFieldSet.CreateBuilder(this.UnknownFields);
               }
-              ParseUnknownField(input, unknownFields, extensionRegistry, tag);
+              ParseUnknownField(input, unknownFields, extensionRegistry, tag, field_name);
               break;
             }
             case 10: {
@@ -12202,26 +12193,26 @@
               if (unknownFields == null) {
                 unknownFields = pb::UnknownFieldSet.CreateBuilder(this.UnknownFields);
               }
-              ParseUnknownField(input, unknownFields, extensionRegistry, tag);
+              ParseUnknownField(input, unknownFields, extensionRegistry, tag, field_name);
               break;
             }
             case 8: {
-              PrimitiveField = input.ReadInt32();
+              result.hasPrimitiveField |= input.ReadInt32(ref result.primitiveField_);
               break;
             }
             case 18: {
-              StringField = input.ReadString();
+              result.hasStringField |= input.ReadString(ref result.stringField_);
               break;
             }
             case 24: {
-              int rawValue = input.ReadEnum();
-              if (!global::System.Enum.IsDefined(typeof(global::Google.ProtocolBuffers.TestProtos.ForeignEnum), rawValue)) {
+              object unknown;
+              if(input.ReadEnum(ref result.enumField_, out unknown)) {
+                result.hasEnumField = true;
+              } else if(unknown is int) {
                 if (unknownFields == null) {
                   unknownFields = pb::UnknownFieldSet.CreateBuilder(this.UnknownFields);
                 }
-                unknownFields.MergeVarintField(3, (ulong) rawValue);
-              } else {
-                EnumField = (global::Google.ProtocolBuffers.TestProtos.ForeignEnum) rawValue;
+                unknownFields.MergeVarintField(3, (ulong)(int)unknown);
               }
               break;
             }
@@ -12235,45 +12226,44 @@
               break;
             }
             case 42: {
-              StringPieceField = input.ReadString();
+              result.hasStringPieceField |= input.ReadString(ref result.stringPieceField_);
               break;
             }
             case 50: {
-              CordField = input.ReadString();
+              result.hasCordField |= input.ReadString(ref result.cordField_);
               break;
             }
             case 56: {
-              AddRepeatedPrimitiveField(input.ReadInt32());
+              input.ReadPrimitiveArray(pbd::FieldType.Int32, tag, field_name, result.repeatedPrimitiveField_);
               break;
             }
             case 66: {
-              AddRepeatedStringField(input.ReadString());
+              input.ReadPrimitiveArray(pbd::FieldType.String, tag, field_name, result.repeatedStringField_);
               break;
             }
             case 72: {
-              int rawValue = input.ReadEnum();
-              if (!global::System.Enum.IsDefined(typeof(global::Google.ProtocolBuffers.TestProtos.ForeignEnum), rawValue)) {
+              scg::ICollection<object> unknownItems;
+              input.ReadEnumArray<global::Google.ProtocolBuffers.TestProtos.ForeignEnum>(tag, field_name, result.repeatedEnumField_, out unknownItems);
+              if (unknownItems != null) {
                 if (unknownFields == null) {
                   unknownFields = pb::UnknownFieldSet.CreateBuilder(this.UnknownFields);
                 }
-                unknownFields.MergeVarintField(9, (ulong) rawValue);
-              } else {
-                AddRepeatedEnumField((global::Google.ProtocolBuffers.TestProtos.ForeignEnum) rawValue);
+                foreach (object rawValue in unknownItems)
+                  if (rawValue is int)
+                    unknownFields.MergeVarintField(9, (ulong)(int)rawValue);
               }
               break;
             }
             case 82: {
-              global::Google.ProtocolBuffers.TestProtos.ForeignMessage.Builder subBuilder = global::Google.ProtocolBuffers.TestProtos.ForeignMessage.CreateBuilder();
-              input.ReadMessage(subBuilder, extensionRegistry);
-              AddRepeatedMessageField(subBuilder.BuildPartial());
+              input.ReadMessageArray(tag, field_name, result.repeatedMessageField_, global::Google.ProtocolBuffers.TestProtos.ForeignMessage.DefaultInstance, extensionRegistry);
               break;
             }
             case 90: {
-              AddRepeatedStringPieceField(input.ReadString());
+              input.ReadPrimitiveArray(pbd::FieldType.String, tag, field_name, result.repeatedStringPieceField_);
               break;
             }
             case 98: {
-              AddRepeatedCordField(input.ReadString());
+              input.ReadPrimitiveArray(pbd::FieldType.String, tag, field_name, result.repeatedCordField_);
               break;
             }
           }
@@ -12822,19 +12812,19 @@
               if (unknownFields == null) {
                 unknownFields = pb::UnknownFieldSet.CreateBuilder(this.UnknownFields);
               }
-              ParseUnknownField(input, unknownFields, extensionRegistry, tag);
+              ParseUnknownField(input, unknownFields, extensionRegistry, tag, field_name);
               break;
             }
             case 8: {
-              MyInt = input.ReadInt64();
+              result.hasMyInt |= input.ReadInt64(ref result.myInt_);
               break;
             }
             case 90: {
-              MyString = input.ReadString();
+              result.hasMyString |= input.ReadString(ref result.myString_);
               break;
             }
             case 813: {
-              MyFloat = input.ReadFloat();
+              result.hasMyFloat |= input.ReadFloat(ref result.myFloat_);
               break;
             }
           }
@@ -13435,83 +13425,83 @@
               if (unknownFields == null) {
                 unknownFields = pb::UnknownFieldSet.CreateBuilder(this.UnknownFields);
               }
-              ParseUnknownField(input, unknownFields, extensionRegistry, tag);
+              ParseUnknownField(input, unknownFields, extensionRegistry, tag, field_name);
               break;
             }
             case 10: {
-              EscapedBytes = input.ReadBytes();
+              result.hasEscapedBytes |= input.ReadBytes(ref result.escapedBytes_);
               break;
             }
             case 16: {
-              LargeUint32 = input.ReadUInt32();
+              result.hasLargeUint32 |= input.ReadUInt32(ref result.largeUint32_);
               break;
             }
             case 24: {
-              LargeUint64 = input.ReadUInt64();
+              result.hasLargeUint64 |= input.ReadUInt64(ref result.largeUint64_);
               break;
             }
             case 32: {
-              SmallInt32 = input.ReadInt32();
+              result.hasSmallInt32 |= input.ReadInt32(ref result.smallInt32_);
               break;
             }
             case 40: {
-              SmallInt64 = input.ReadInt64();
+              result.hasSmallInt64 |= input.ReadInt64(ref result.smallInt64_);
               break;
             }
             case 50: {
-              Utf8String = input.ReadString();
+              result.hasUtf8String |= input.ReadString(ref result.utf8String_);
               break;
             }
             case 61: {
-              ZeroFloat = input.ReadFloat();
+              result.hasZeroFloat |= input.ReadFloat(ref result.zeroFloat_);
               break;
             }
             case 69: {
-              OneFloat = input.ReadFloat();
+              result.hasOneFloat |= input.ReadFloat(ref result.oneFloat_);
               break;
             }
             case 77: {
-              SmallFloat = input.ReadFloat();
+              result.hasSmallFloat |= input.ReadFloat(ref result.smallFloat_);
               break;
             }
             case 85: {
-              NegativeOneFloat = input.ReadFloat();
+              result.hasNegativeOneFloat |= input.ReadFloat(ref result.negativeOneFloat_);
               break;
             }
             case 93: {
-              NegativeFloat = input.ReadFloat();
+              result.hasNegativeFloat |= input.ReadFloat(ref result.negativeFloat_);
               break;
             }
             case 101: {
-              LargeFloat = input.ReadFloat();
+              result.hasLargeFloat |= input.ReadFloat(ref result.largeFloat_);
               break;
             }
             case 109: {
-              SmallNegativeFloat = input.ReadFloat();
+              result.hasSmallNegativeFloat |= input.ReadFloat(ref result.smallNegativeFloat_);
               break;
             }
             case 113: {
-              InfDouble = input.ReadDouble();
+              result.hasInfDouble |= input.ReadDouble(ref result.infDouble_);
               break;
             }
             case 121: {
-              NegInfDouble = input.ReadDouble();
+              result.hasNegInfDouble |= input.ReadDouble(ref result.negInfDouble_);
               break;
             }
             case 129: {
-              NanDouble = input.ReadDouble();
+              result.hasNanDouble |= input.ReadDouble(ref result.nanDouble_);
               break;
             }
             case 141: {
-              InfFloat = input.ReadFloat();
+              result.hasInfFloat |= input.ReadFloat(ref result.infFloat_);
               break;
             }
             case 149: {
-              NegInfFloat = input.ReadFloat();
+              result.hasNegInfFloat |= input.ReadFloat(ref result.negInfFloat_);
               break;
             }
             case 157: {
-              NanFloat = input.ReadFloat();
+              result.hasNanFloat |= input.ReadFloat(ref result.nanFloat_);
               break;
             }
           }
@@ -14061,11 +14051,11 @@
               if (unknownFields == null) {
                 unknownFields = pb::UnknownFieldSet.CreateBuilder(this.UnknownFields);
               }
-              ParseUnknownField(input, unknownFields, extensionRegistry, tag);
+              ParseUnknownField(input, unknownFields, extensionRegistry, tag, field_name);
               break;
             }
             case 10: {
-              Data = input.ReadString();
+              result.hasData |= input.ReadString(ref result.data_);
               break;
             }
           }
@@ -14286,11 +14276,11 @@
               if (unknownFields == null) {
                 unknownFields = pb::UnknownFieldSet.CreateBuilder(this.UnknownFields);
               }
-              ParseUnknownField(input, unknownFields, extensionRegistry, tag);
+              ParseUnknownField(input, unknownFields, extensionRegistry, tag, field_name);
               break;
             }
             case 10: {
-              Data = input.ReadBytes();
+              result.hasData |= input.ReadBytes(ref result.data_);
               break;
             }
           }
@@ -14921,141 +14911,72 @@
               if (unknownFields == null) {
                 unknownFields = pb::UnknownFieldSet.CreateBuilder(this.UnknownFields);
               }
-              ParseUnknownField(input, unknownFields, extensionRegistry, tag);
+              ParseUnknownField(input, unknownFields, extensionRegistry, tag, field_name);
               break;
             }
             case 722: {
-              int length = input.ReadInt32();
-              int limit = input.PushLimit(length);
-              while (!input.ReachedLimit) {
-                AddPackedInt32(input.ReadInt32());
-              }
-              input.PopLimit(limit);
+              input.ReadPrimitiveArray(pbd::FieldType.Int32, tag, field_name, result.packedInt32_);
               break;
             }
             case 730: {
-              int length = input.ReadInt32();
-              int limit = input.PushLimit(length);
-              while (!input.ReachedLimit) {
-                AddPackedInt64(input.ReadInt64());
-              }
-              input.PopLimit(limit);
+              input.ReadPrimitiveArray(pbd::FieldType.Int64, tag, field_name, result.packedInt64_);
               break;
             }
             case 738: {
-              int length = input.ReadInt32();
-              int limit = input.PushLimit(length);
-              while (!input.ReachedLimit) {
-                AddPackedUint32(input.ReadUInt32());
-              }
-              input.PopLimit(limit);
+              input.ReadPrimitiveArray(pbd::FieldType.UInt32, tag, field_name, result.packedUint32_);
               break;
             }
             case 746: {
-              int length = input.ReadInt32();
-              int limit = input.PushLimit(length);
-              while (!input.ReachedLimit) {
-                AddPackedUint64(input.ReadUInt64());
-              }
-              input.PopLimit(limit);
+              input.ReadPrimitiveArray(pbd::FieldType.UInt64, tag, field_name, result.packedUint64_);
               break;
             }
             case 754: {
-              int length = input.ReadInt32();
-              int limit = input.PushLimit(length);
-              while (!input.ReachedLimit) {
-                AddPackedSint32(input.ReadSInt32());
-              }
-              input.PopLimit(limit);
+              input.ReadPrimitiveArray(pbd::FieldType.SInt32, tag, field_name, result.packedSint32_);
               break;
             }
             case 762: {
-              int length = input.ReadInt32();
-              int limit = input.PushLimit(length);
-              while (!input.ReachedLimit) {
-                AddPackedSint64(input.ReadSInt64());
-              }
-              input.PopLimit(limit);
+              input.ReadPrimitiveArray(pbd::FieldType.SInt64, tag, field_name, result.packedSint64_);
               break;
             }
             case 770: {
-              int length = input.ReadInt32();
-              int limit = input.PushLimit(length);
-              while (!input.ReachedLimit) {
-                AddPackedFixed32(input.ReadFixed32());
-              }
-              input.PopLimit(limit);
+              input.ReadPrimitiveArray(pbd::FieldType.Fixed32, tag, field_name, result.packedFixed32_);
               break;
             }
             case 778: {
-              int length = input.ReadInt32();
-              int limit = input.PushLimit(length);
-              while (!input.ReachedLimit) {
-                AddPackedFixed64(input.ReadFixed64());
-              }
-              input.PopLimit(limit);
+              input.ReadPrimitiveArray(pbd::FieldType.Fixed64, tag, field_name, result.packedFixed64_);
               break;
             }
             case 786: {
-              int length = input.ReadInt32();
-              int limit = input.PushLimit(length);
-              while (!input.ReachedLimit) {
-                AddPackedSfixed32(input.ReadSFixed32());
-              }
-              input.PopLimit(limit);
+              input.ReadPrimitiveArray(pbd::FieldType.SFixed32, tag, field_name, result.packedSfixed32_);
               break;
             }
             case 794: {
-              int length = input.ReadInt32();
-              int limit = input.PushLimit(length);
-              while (!input.ReachedLimit) {
-                AddPackedSfixed64(input.ReadSFixed64());
-              }
-              input.PopLimit(limit);
+              input.ReadPrimitiveArray(pbd::FieldType.SFixed64, tag, field_name, result.packedSfixed64_);
               break;
             }
             case 802: {
-              int length = input.ReadInt32();
-              int limit = input.PushLimit(length);
-              while (!input.ReachedLimit) {
-                AddPackedFloat(input.ReadFloat());
-              }
-              input.PopLimit(limit);
+              input.ReadPrimitiveArray(pbd::FieldType.Float, tag, field_name, result.packedFloat_);
               break;
             }
             case 810: {
-              int length = input.ReadInt32();
-              int limit = input.PushLimit(length);
-              while (!input.ReachedLimit) {
-                AddPackedDouble(input.ReadDouble());
-              }
-              input.PopLimit(limit);
+              input.ReadPrimitiveArray(pbd::FieldType.Double, tag, field_name, result.packedDouble_);
               break;
             }
             case 818: {
-              int length = input.ReadInt32();
-              int limit = input.PushLimit(length);
-              while (!input.ReachedLimit) {
-                AddPackedBool(input.ReadBool());
-              }
-              input.PopLimit(limit);
+              input.ReadPrimitiveArray(pbd::FieldType.Bool, tag, field_name, result.packedBool_);
               break;
             }
             case 826: {
-              int length = input.ReadInt32();
-              int oldLimit = input.PushLimit(length);
-              while (!input.ReachedLimit) {
-                int rawValue = input.ReadEnum();
-                if (!global::System.Enum.IsDefined(typeof(global::Google.ProtocolBuffers.TestProtos.ForeignEnum), rawValue)) {
-                  if (unknownFields == null) {
-                    unknownFields = pb::UnknownFieldSet.CreateBuilder(this.UnknownFields);
-                  }
-                  unknownFields.MergeVarintField(103, (ulong) rawValue);
-                } else {
-                  AddPackedEnum((global::Google.ProtocolBuffers.TestProtos.ForeignEnum) rawValue);
+              scg::ICollection<object> unknownItems;
+              input.ReadEnumArray<global::Google.ProtocolBuffers.TestProtos.ForeignEnum>(tag, field_name, result.packedEnum_, out unknownItems);
+              if (unknownItems != null) {
+                if (unknownFields == null) {
+                  unknownFields = pb::UnknownFieldSet.CreateBuilder(this.UnknownFields);
                 }
+                foreach (object rawValue in unknownItems)
+                  if (rawValue is int)
+                    unknownFields.MergeVarintField(103, (ulong)(int)rawValue);
               }
-              input.PopLimit(oldLimit);
               break;
             }
           }
@@ -15996,70 +15917,71 @@
               if (unknownFields == null) {
                 unknownFields = pb::UnknownFieldSet.CreateBuilder(this.UnknownFields);
               }
-              ParseUnknownField(input, unknownFields, extensionRegistry, tag);
+              ParseUnknownField(input, unknownFields, extensionRegistry, tag, field_name);
               break;
             }
             case 720: {
-              AddUnpackedInt32(input.ReadInt32());
+              input.ReadPrimitiveArray(pbd::FieldType.Int32, tag, field_name, result.unpackedInt32_);
               break;
             }
             case 728: {
-              AddUnpackedInt64(input.ReadInt64());
+              input.ReadPrimitiveArray(pbd::FieldType.Int64, tag, field_name, result.unpackedInt64_);
               break;
             }
             case 736: {
-              AddUnpackedUint32(input.ReadUInt32());
+              input.ReadPrimitiveArray(pbd::FieldType.UInt32, tag, field_name, result.unpackedUint32_);
               break;
             }
             case 744: {
-              AddUnpackedUint64(input.ReadUInt64());
+              input.ReadPrimitiveArray(pbd::FieldType.UInt64, tag, field_name, result.unpackedUint64_);
               break;
             }
             case 752: {
-              AddUnpackedSint32(input.ReadSInt32());
+              input.ReadPrimitiveArray(pbd::FieldType.SInt32, tag, field_name, result.unpackedSint32_);
               break;
             }
             case 760: {
-              AddUnpackedSint64(input.ReadSInt64());
+              input.ReadPrimitiveArray(pbd::FieldType.SInt64, tag, field_name, result.unpackedSint64_);
               break;
             }
             case 773: {
-              AddUnpackedFixed32(input.ReadFixed32());
+              input.ReadPrimitiveArray(pbd::FieldType.Fixed32, tag, field_name, result.unpackedFixed32_);
               break;
             }
             case 777: {
-              AddUnpackedFixed64(input.ReadFixed64());
+              input.ReadPrimitiveArray(pbd::FieldType.Fixed64, tag, field_name, result.unpackedFixed64_);
               break;
             }
             case 789: {
-              AddUnpackedSfixed32(input.ReadSFixed32());
+              input.ReadPrimitiveArray(pbd::FieldType.SFixed32, tag, field_name, result.unpackedSfixed32_);
               break;
             }
             case 793: {
-              AddUnpackedSfixed64(input.ReadSFixed64());
+              input.ReadPrimitiveArray(pbd::FieldType.SFixed64, tag, field_name, result.unpackedSfixed64_);
               break;
             }
             case 805: {
-              AddUnpackedFloat(input.ReadFloat());
+              input.ReadPrimitiveArray(pbd::FieldType.Float, tag, field_name, result.unpackedFloat_);
               break;
             }
             case 809: {
-              AddUnpackedDouble(input.ReadDouble());
+              input.ReadPrimitiveArray(pbd::FieldType.Double, tag, field_name, result.unpackedDouble_);
               break;
             }
             case 816: {
-              AddUnpackedBool(input.ReadBool());
+              input.ReadPrimitiveArray(pbd::FieldType.Bool, tag, field_name, result.unpackedBool_);
               break;
             }
             case 824: {
-              int rawValue = input.ReadEnum();
-              if (!global::System.Enum.IsDefined(typeof(global::Google.ProtocolBuffers.TestProtos.ForeignEnum), rawValue)) {
+              scg::ICollection<object> unknownItems;
+              input.ReadEnumArray<global::Google.ProtocolBuffers.TestProtos.ForeignEnum>(tag, field_name, result.unpackedEnum_, out unknownItems);
+              if (unknownItems != null) {
                 if (unknownFields == null) {
                   unknownFields = pb::UnknownFieldSet.CreateBuilder(this.UnknownFields);
                 }
-                unknownFields.MergeVarintField(103, (ulong) rawValue);
-              } else {
-                AddUnpackedEnum((global::Google.ProtocolBuffers.TestProtos.ForeignEnum) rawValue);
+                foreach (object rawValue in unknownItems)
+                  if (rawValue is int)
+                    unknownFields.MergeVarintField(103, (ulong)(int)rawValue);
               }
               break;
             }
@@ -16632,7 +16554,7 @@
               if (unknownFields == null) {
                 unknownFields = pb::UnknownFieldSet.CreateBuilder(this.UnknownFields);
               }
-              ParseUnknownField(input, unknownFields, extensionRegistry, tag);
+              ParseUnknownField(input, unknownFields, extensionRegistry, tag, field_name);
               break;
             }
           }
@@ -16872,11 +16794,11 @@
                   if (unknownFields == null) {
                     unknownFields = pb::UnknownFieldSet.CreateBuilder(this.UnknownFields);
                   }
-                  ParseUnknownField(input, unknownFields, extensionRegistry, tag);
+                  ParseUnknownField(input, unknownFields, extensionRegistry, tag, field_name);
                   break;
                 }
                 case 16800: {
-                  DynamicField = input.ReadInt32();
+                  result.hasDynamicField |= input.ReadInt32(ref result.dynamicField_);
                   break;
                 }
               }
@@ -17209,34 +17131,34 @@
               if (unknownFields == null) {
                 unknownFields = pb::UnknownFieldSet.CreateBuilder(this.UnknownFields);
               }
-              ParseUnknownField(input, unknownFields, extensionRegistry, tag);
+              ParseUnknownField(input, unknownFields, extensionRegistry, tag, field_name);
               break;
             }
             case 16005: {
-              ScalarExtension = input.ReadFixed32();
+              result.hasScalarExtension |= input.ReadFixed32(ref result.scalarExtension_);
               break;
             }
             case 16008: {
-              int rawValue = input.ReadEnum();
-              if (!global::System.Enum.IsDefined(typeof(global::Google.ProtocolBuffers.TestProtos.ForeignEnum), rawValue)) {
+              object unknown;
+              if(input.ReadEnum(ref result.enumExtension_, out unknown)) {
+                result.hasEnumExtension = true;
+              } else if(unknown is int) {
                 if (unknownFields == null) {
                   unknownFields = pb::UnknownFieldSet.CreateBuilder(this.UnknownFields);
                 }
-                unknownFields.MergeVarintField(2001, (ulong) rawValue);
-              } else {
-                EnumExtension = (global::Google.ProtocolBuffers.TestProtos.ForeignEnum) rawValue;
+                unknownFields.MergeVarintField(2001, (ulong)(int)unknown);
               }
               break;
             }
             case 16016: {
-              int rawValue = input.ReadEnum();
-              if (!global::System.Enum.IsDefined(typeof(global::Google.ProtocolBuffers.TestProtos.TestDynamicExtensions.Types.DynamicEnumType), rawValue)) {
+              object unknown;
+              if(input.ReadEnum(ref result.dynamicEnumExtension_, out unknown)) {
+                result.hasDynamicEnumExtension = true;
+              } else if(unknown is int) {
                 if (unknownFields == null) {
                   unknownFields = pb::UnknownFieldSet.CreateBuilder(this.UnknownFields);
                 }
-                unknownFields.MergeVarintField(2002, (ulong) rawValue);
-              } else {
-                DynamicEnumExtension = (global::Google.ProtocolBuffers.TestProtos.TestDynamicExtensions.Types.DynamicEnumType) rawValue;
+                unknownFields.MergeVarintField(2002, (ulong)(int)unknown);
               }
               break;
             }
@@ -17259,16 +17181,11 @@
               break;
             }
             case 16042: {
-              AddRepeatedExtension(input.ReadString());
+              input.ReadPrimitiveArray(pbd::FieldType.String, tag, field_name, result.repeatedExtension_);
               break;
             }
             case 16050: {
-              int length = input.ReadInt32();
-              int limit = input.PushLimit(length);
-              while (!input.ReachedLimit) {
-                AddPackedExtension(input.ReadSInt32());
-              }
-              input.PopLimit(limit);
+              input.ReadPrimitiveArray(pbd::FieldType.SInt32, tag, field_name, result.packedExtension_);
               break;
             }
           }
@@ -17795,31 +17712,31 @@
               if (unknownFields == null) {
                 unknownFields = pb::UnknownFieldSet.CreateBuilder(this.UnknownFields);
               }
-              ParseUnknownField(input, unknownFields, extensionRegistry, tag);
+              ParseUnknownField(input, unknownFields, extensionRegistry, tag, field_name);
               break;
             }
             case 101: {
-              AddRepeatedFixed32(input.ReadFixed32());
+              input.ReadPrimitiveArray(pbd::FieldType.Fixed32, tag, field_name, result.repeatedFixed32_);
               break;
             }
             case 104: {
-              AddRepeatedInt32(input.ReadInt32());
+              input.ReadPrimitiveArray(pbd::FieldType.Int32, tag, field_name, result.repeatedInt32_);
               break;
             }
             case 16369: {
-              AddRepeatedFixed64(input.ReadFixed64());
+              input.ReadPrimitiveArray(pbd::FieldType.Fixed64, tag, field_name, result.repeatedFixed64_);
               break;
             }
             case 16376: {
-              AddRepeatedInt64(input.ReadInt64());
+              input.ReadPrimitiveArray(pbd::FieldType.Int64, tag, field_name, result.repeatedInt64_);
               break;
             }
             case 2097141: {
-              AddRepeatedFloat(input.ReadFloat());
+              input.ReadPrimitiveArray(pbd::FieldType.Float, tag, field_name, result.repeatedFloat_);
               break;
             }
             case 2097144: {
-              AddRepeatedUint64(input.ReadUInt64());
+              input.ReadPrimitiveArray(pbd::FieldType.UInt64, tag, field_name, result.repeatedUint64_);
               break;
             }
           }
@@ -18173,7 +18090,7 @@
               if (unknownFields == null) {
                 unknownFields = pb::UnknownFieldSet.CreateBuilder(this.UnknownFields);
               }
-              ParseUnknownField(input, unknownFields, extensionRegistry, tag);
+              ParseUnknownField(input, unknownFields, extensionRegistry, tag, field_name);
               break;
             }
           }
@@ -18356,7 +18273,7 @@
               if (unknownFields == null) {
                 unknownFields = pb::UnknownFieldSet.CreateBuilder(this.UnknownFields);
               }
-              ParseUnknownField(input, unknownFields, extensionRegistry, tag);
+              ParseUnknownField(input, unknownFields, extensionRegistry, tag, field_name);
               break;
             }
           }
@@ -18539,7 +18456,7 @@
               if (unknownFields == null) {
                 unknownFields = pb::UnknownFieldSet.CreateBuilder(this.UnknownFields);
               }
-              ParseUnknownField(input, unknownFields, extensionRegistry, tag);
+              ParseUnknownField(input, unknownFields, extensionRegistry, tag, field_name);
               break;
             }
           }
@@ -18722,7 +18639,7 @@
               if (unknownFields == null) {
                 unknownFields = pb::UnknownFieldSet.CreateBuilder(this.UnknownFields);
               }
-              ParseUnknownField(input, unknownFields, extensionRegistry, tag);
+              ParseUnknownField(input, unknownFields, extensionRegistry, tag, field_name);
               break;
             }
           }