Extracted initial ICodedOutputStream interface
diff --git a/src/ProtocolBuffers/CodedOutputStream.cs b/src/ProtocolBuffers/CodedOutputStream.cs
index ee8a5dc..7ebba9b 100644
--- a/src/ProtocolBuffers/CodedOutputStream.cs
+++ b/src/ProtocolBuffers/CodedOutputStream.cs
@@ -55,7 +55,7 @@
     /// methods are taken from the protocol buffer type names, not .NET types.

     /// (Hence WriteFloat instead of WriteSingle, and WriteBool instead of WriteBoolean.)

     /// </remarks>

-    public sealed partial class CodedOutputStream

+    public sealed partial class CodedOutputStream : ICodedOutputStream

     {

         /// <summary>

         /// The buffer size used by CreateInstance(Stream).

@@ -408,9 +408,9 @@
                     break;

                 case FieldType.Enum:

                     if(value is System.Enum)

-                        WriteEnum(fieldNumber, fieldName, ((IConvertible)value).ToInt32(CultureInfo.InvariantCulture), value.ToString());

+                        WriteEnum(fieldNumber, fieldName, ((IConvertible)value).ToInt32(CultureInfo.InvariantCulture), null/*not used*/);

                     else

-                        WriteEnum(fieldNumber, fieldName, ((IEnumLite) value).Number, ((IEnumLite) value).Name);

+                        WriteEnum(fieldNumber, fieldName, ((IEnumLite) value).Number, null/*not used*/);

                     break;

             }

         }

@@ -803,568 +803,6 @@
         }

 

         #endregion

-

-        #region Size computations

-

-        private const int LittleEndian64Size = 8;

-        private const int LittleEndian32Size = 4;

-

-        /// <summary>

-        /// Compute the number of bytes that would be needed to encode a

-        /// double field, including the tag.

-        /// </summary>

-        public static int ComputeDoubleSize(int fieldNumber, double value)

-        {

-            return ComputeTagSize(fieldNumber) + LittleEndian64Size;

-        }

-

-        /// <summary>

-        /// Compute the number of bytes that would be needed to encode a

-        /// float field, including the tag.

-        /// </summary>

-        public static int ComputeFloatSize(int fieldNumber, float value)

-        {

-            return ComputeTagSize(fieldNumber) + LittleEndian32Size;

-        }

-

-        /// <summary>

-        /// Compute the number of bytes that would be needed to encode a

-        /// uint64 field, including the tag.

-        /// </summary>

-        [CLSCompliant(false)]

-        public static int ComputeUInt64Size(int fieldNumber, ulong value)

-        {

-            return ComputeTagSize(fieldNumber) + ComputeRawVarint64Size(value);

-        }

-

-        /// <summary>

-        /// Compute the number of bytes that would be needed to encode an

-        /// int64 field, including the tag.

-        /// </summary>

-        public static int ComputeInt64Size(int fieldNumber, long value)

-        {

-            return ComputeTagSize(fieldNumber) + ComputeRawVarint64Size((ulong) value);

-        }

-

-        /// <summary>

-        /// Compute the number of bytes that would be needed to encode an

-        /// int32 field, including the tag.

-        /// </summary>

-        public static int ComputeInt32Size(int fieldNumber, int value)

-        {

-            if (value >= 0)

-            {

-                return ComputeTagSize(fieldNumber) + ComputeRawVarint32Size((uint) value);

-            }

-            else

-            {

-                // Must sign-extend.

-                return ComputeTagSize(fieldNumber) + 10;

-            }

-        }

-

-        /// <summary>

-        /// Compute the number of bytes that would be needed to encode a

-        /// fixed64 field, including the tag.

-        /// </summary>

-        [CLSCompliant(false)]

-        public static int ComputeFixed64Size(int fieldNumber, ulong value)

-        {

-            return ComputeTagSize(fieldNumber) + LittleEndian64Size;

-        }

-

-        /// <summary>

-        /// Compute the number of bytes that would be needed to encode a

-        /// fixed32 field, including the tag.

-        /// </summary>

-        [CLSCompliant(false)]

-        public static int ComputeFixed32Size(int fieldNumber, uint value)

-        {

-            return ComputeTagSize(fieldNumber) + LittleEndian32Size;

-        }

-

-        /// <summary>

-        /// Compute the number of bytes that would be needed to encode a

-        /// bool field, including the tag.

-        /// </summary>

-        public static int ComputeBoolSize(int fieldNumber, bool value)

-        {

-            return ComputeTagSize(fieldNumber) + 1;

-        }

-

-        /// <summary>

-        /// Compute the number of bytes that would be needed to encode a

-        /// string field, including the tag.

-        /// </summary>

-        public static int ComputeStringSize(int fieldNumber, String value)

-        {

-            int byteArraySize = Encoding.UTF8.GetByteCount(value);

-            return ComputeTagSize(fieldNumber) +

-                   ComputeRawVarint32Size((uint) byteArraySize) +

-                   byteArraySize;

-        }

-

-        /// <summary>

-        /// Compute the number of bytes that would be needed to encode a

-        /// group field, including the tag.

-        /// </summary>

-        public static int ComputeGroupSize(int fieldNumber, IMessageLite value)

-        {

-            return ComputeTagSize(fieldNumber)*2 + value.SerializedSize;

-        }

-

-        /// <summary>

-        /// Compute the number of bytes that would be needed to encode a

-        /// group field represented by an UnknownFieldSet, including the tag.

-        /// </summary>

-        [Obsolete]

-        public static int ComputeUnknownGroupSize(int fieldNumber,

-                                                  IMessageLite value)

-        {

-            return ComputeTagSize(fieldNumber)*2 + value.SerializedSize;

-        }

-

-        /// <summary>

-        /// Compute the number of bytes that would be needed to encode an

-        /// embedded message field, including the tag.

-        /// </summary>

-        public static int ComputeMessageSize(int fieldNumber, IMessageLite value)

-        {

-            int size = value.SerializedSize;

-            return ComputeTagSize(fieldNumber) + ComputeRawVarint32Size((uint) size) + size;

-        }

-

-        /// <summary>

-        /// Compute the number of bytes that would be needed to encode a

-        /// bytes field, including the tag.

-        /// </summary>

-        public static int ComputeBytesSize(int fieldNumber, ByteString value)

-        {

-            return ComputeTagSize(fieldNumber) +

-                   ComputeRawVarint32Size((uint) value.Length) +

-                   value.Length;

-        }

-

-        /// <summary>

-        /// Compute the number of bytes that would be needed to encode a

-        /// uint32 field, including the tag.

-        /// </summary>

-        [CLSCompliant(false)]

-        public static int ComputeUInt32Size(int fieldNumber, uint value)

-        {

-            return ComputeTagSize(fieldNumber) + ComputeRawVarint32Size(value);

-        }

-

-        /// <summary>

-        /// Compute the number of bytes that would be needed to encode a

-        /// enum field, including the tag. The caller is responsible for

-        /// converting the enum value to its numeric value.

-        /// </summary>

-        public static int ComputeEnumSize(int fieldNumber, int value)

-        {

-            return ComputeTagSize(fieldNumber) + ComputeRawVarint32Size((uint) value);

-        }

-

-        /// <summary>

-        /// Compute the number of bytes that would be needed to encode an

-        /// sfixed32 field, including the tag.

-        /// </summary>

-        public static int ComputeSFixed32Size(int fieldNumber, int value)

-        {

-            return ComputeTagSize(fieldNumber) + LittleEndian32Size;

-        }

-

-        /// <summary>

-        /// Compute the number of bytes that would be needed to encode an

-        /// sfixed64 field, including the tag.

-        /// </summary>

-        public static int ComputeSFixed64Size(int fieldNumber, long value)

-        {

-            return ComputeTagSize(fieldNumber) + LittleEndian64Size;

-        }

-

-        /// <summary>

-        /// Compute the number of bytes that would be needed to encode an

-        /// sint32 field, including the tag.

-        /// </summary>

-        public static int ComputeSInt32Size(int fieldNumber, int value)

-        {

-            return ComputeTagSize(fieldNumber) + ComputeRawVarint32Size(EncodeZigZag32(value));

-        }

-

-        /// <summary>

-        /// Compute the number of bytes that would be needed to encode an

-        /// sint64 field, including the tag.

-        /// </summary>

-        public static int ComputeSInt64Size(int fieldNumber, long value)

-        {

-            return ComputeTagSize(fieldNumber) + ComputeRawVarint64Size(EncodeZigZag64(value));

-        }

-

-        /// <summary>

-        /// Compute the number of bytes that would be needed to encode a

-        /// double field, including the tag.

-        /// </summary>

-        public static int ComputeDoubleSizeNoTag(double value)

-        {

-            return LittleEndian64Size;

-        }

-

-        /// <summary>

-        /// Compute the number of bytes that would be needed to encode a

-        /// float field, including the tag.

-        /// </summary>

-        public static int ComputeFloatSizeNoTag(float value)

-        {

-            return LittleEndian32Size;

-        }

-

-        /// <summary>

-        /// Compute the number of bytes that would be needed to encode a

-        /// uint64 field, including the tag.

-        /// </summary>

-        [CLSCompliant(false)]

-        public static int ComputeUInt64SizeNoTag(ulong value)

-        {

-            return ComputeRawVarint64Size(value);

-        }

-

-        /// <summary>

-        /// Compute the number of bytes that would be needed to encode an

-        /// int64 field, including the tag.

-        /// </summary>

-        public static int ComputeInt64SizeNoTag(long value)

-        {

-            return ComputeRawVarint64Size((ulong) value);

-        }

-

-        /// <summary>

-        /// Compute the number of bytes that would be needed to encode an

-        /// int32 field, including the tag.

-        /// </summary>

-        public static int ComputeInt32SizeNoTag(int value)

-        {

-            if (value >= 0)

-            {

-                return ComputeRawVarint32Size((uint) value);

-            }

-            else

-            {

-                // Must sign-extend.

-                return 10;

-            }

-        }

-

-        /// <summary>

-        /// Compute the number of bytes that would be needed to encode a

-        /// fixed64 field, including the tag.

-        /// </summary>

-        [CLSCompliant(false)]

-        public static int ComputeFixed64SizeNoTag(ulong value)

-        {

-            return LittleEndian64Size;

-        }

-

-        /// <summary>

-        /// Compute the number of bytes that would be needed to encode a

-        /// fixed32 field, including the tag.

-        /// </summary>

-        [CLSCompliant(false)]

-        public static int ComputeFixed32SizeNoTag(uint value)

-        {

-            return LittleEndian32Size;

-        }

-

-        /// <summary>

-        /// Compute the number of bytes that would be needed to encode a

-        /// bool field, including the tag.

-        /// </summary>

-        public static int ComputeBoolSizeNoTag(bool value)

-        {

-            return 1;

-        }

-

-        /// <summary>

-        /// Compute the number of bytes that would be needed to encode a

-        /// string field, including the tag.

-        /// </summary>

-        public static int ComputeStringSizeNoTag(String value)

-        {

-            int byteArraySize = Encoding.UTF8.GetByteCount(value);

-            return ComputeRawVarint32Size((uint) byteArraySize) +

-                   byteArraySize;

-        }

-

-        /// <summary>

-        /// Compute the number of bytes that would be needed to encode a

-        /// group field, including the tag.

-        /// </summary>

-        public static int ComputeGroupSizeNoTag(IMessageLite value)

-        {

-            return value.SerializedSize;

-        }

-

-        /// <summary>

-        /// Compute the number of bytes that would be needed to encode a

-        /// group field represented by an UnknownFieldSet, including the tag.

-        /// </summary>

-        [Obsolete]

-        public static int ComputeUnknownGroupSizeNoTag(IMessageLite value)

-        {

-            return value.SerializedSize;

-        }

-

-        /// <summary>

-        /// Compute the number of bytes that would be needed to encode an

-        /// embedded message field, including the tag.

-        /// </summary>

-        public static int ComputeMessageSizeNoTag(IMessageLite value)

-        {

-            int size = value.SerializedSize;

-            return ComputeRawVarint32Size((uint) size) + size;

-        }

-

-        /// <summary>

-        /// Compute the number of bytes that would be needed to encode a

-        /// bytes field, including the tag.

-        /// </summary>

-        public static int ComputeBytesSizeNoTag(ByteString value)

-        {

-            return ComputeRawVarint32Size((uint) value.Length) +

-                   value.Length;

-        }

-

-        /// <summary>

-        /// Compute the number of bytes that would be needed to encode a

-        /// uint32 field, including the tag.

-        /// </summary>

-        [CLSCompliant(false)]

-        public static int ComputeUInt32SizeNoTag(uint value)

-        {

-            return ComputeRawVarint32Size(value);

-        }

-

-        /// <summary>

-        /// Compute the number of bytes that would be needed to encode a

-        /// enum field, including the tag. The caller is responsible for

-        /// converting the enum value to its numeric value.

-        /// </summary>

-        public static int ComputeEnumSizeNoTag(int value)

-        {

-            return ComputeRawVarint32Size((uint) value);

-        }

-

-        /// <summary>

-        /// Compute the number of bytes that would be needed to encode an

-        /// sfixed32 field, including the tag.

-        /// </summary>

-        public static int ComputeSFixed32SizeNoTag(int value)

-        {

-            return LittleEndian32Size;

-        }

-

-        /// <summary>

-        /// Compute the number of bytes that would be needed to encode an

-        /// sfixed64 field, including the tag.

-        /// </summary>

-        public static int ComputeSFixed64SizeNoTag(long value)

-        {

-            return LittleEndian64Size;

-        }

-

-        /// <summary>

-        /// Compute the number of bytes that would be needed to encode an

-        /// sint32 field, including the tag.

-        /// </summary>

-        public static int ComputeSInt32SizeNoTag(int value)

-        {

-            return ComputeRawVarint32Size(EncodeZigZag32(value));

-        }

-

-        /// <summary>

-        /// Compute the number of bytes that would be needed to encode an

-        /// sint64 field, including the tag.

-        /// </summary>

-        public static int ComputeSInt64SizeNoTag(long value)

-        {

-            return ComputeRawVarint64Size(EncodeZigZag64(value));

-        }

-

-        /*

-     * Compute the number of bytes that would be needed to encode a

-     * MessageSet extension to the stream.  For historical reasons,

-     * the wire format differs from normal fields.

-     */

-

-        /// <summary>

-        /// Compute the number of bytes that would be needed to encode a

-        /// MessageSet extension to the stream. For historical reasons,

-        /// the wire format differs from normal fields.

-        /// </summary>

-        public static int ComputeMessageSetExtensionSize(int fieldNumber, IMessageLite value)

-        {

-            return ComputeTagSize(WireFormat.MessageSetField.Item)*2 +

-                   ComputeUInt32Size(WireFormat.MessageSetField.TypeID, (uint) fieldNumber) +

-                   ComputeMessageSize(WireFormat.MessageSetField.Message, value);

-        }

-

-        /// <summary>

-        /// Compute the number of bytes that would be needed to encode an

-        /// unparsed MessageSet extension field to the stream. For

-        /// historical reasons, the wire format differs from normal fields.

-        /// </summary>

-        public static int ComputeRawMessageSetExtensionSize(int fieldNumber, ByteString value)

-        {

-            return ComputeTagSize(WireFormat.MessageSetField.Item)*2 +

-                   ComputeUInt32Size(WireFormat.MessageSetField.TypeID, (uint) fieldNumber) +

-                   ComputeBytesSize(WireFormat.MessageSetField.Message, value);

-        }

-

-        /// <summary>

-        /// Compute the number of bytes that would be needed to encode a varint.

-        /// </summary>

-        [CLSCompliant(false)]

-        public static int ComputeRawVarint32Size(uint value)

-        {

-            if ((value & (0xffffffff << 7)) == 0) return 1;

-            if ((value & (0xffffffff << 14)) == 0) return 2;

-            if ((value & (0xffffffff << 21)) == 0) return 3;

-            if ((value & (0xffffffff << 28)) == 0) return 4;

-            return 5;

-        }

-

-        /// <summary>

-        /// Compute the number of bytes that would be needed to encode a varint.

-        /// </summary>

-        [CLSCompliant(false)]

-        public static int ComputeRawVarint64Size(ulong value)

-        {

-            if ((value & (0xffffffffffffffffL << 7)) == 0) return 1;

-            if ((value & (0xffffffffffffffffL << 14)) == 0) return 2;

-            if ((value & (0xffffffffffffffffL << 21)) == 0) return 3;

-            if ((value & (0xffffffffffffffffL << 28)) == 0) return 4;

-            if ((value & (0xffffffffffffffffL << 35)) == 0) return 5;

-            if ((value & (0xffffffffffffffffL << 42)) == 0) return 6;

-            if ((value & (0xffffffffffffffffL << 49)) == 0) return 7;

-            if ((value & (0xffffffffffffffffL << 56)) == 0) return 8;

-            if ((value & (0xffffffffffffffffL << 63)) == 0) return 9;

-            return 10;

-        }

-

-        /// <summary>

-        /// Compute the number of bytes that would be needed to encode a

-        /// field of arbitrary type, including the tag, to the stream.

-        /// </summary>

-        public static int ComputeFieldSize(FieldType fieldType, int fieldNumber, Object value)

-        {

-            switch (fieldType)

-            {

-                case FieldType.Double:

-                    return ComputeDoubleSize(fieldNumber, (double) value);

-                case FieldType.Float:

-                    return ComputeFloatSize(fieldNumber, (float) value);

-                case FieldType.Int64:

-                    return ComputeInt64Size(fieldNumber, (long) value);

-                case FieldType.UInt64:

-                    return ComputeUInt64Size(fieldNumber, (ulong) value);

-                case FieldType.Int32:

-                    return ComputeInt32Size(fieldNumber, (int) value);

-                case FieldType.Fixed64:

-                    return ComputeFixed64Size(fieldNumber, (ulong) value);

-                case FieldType.Fixed32:

-                    return ComputeFixed32Size(fieldNumber, (uint) value);

-                case FieldType.Bool:

-                    return ComputeBoolSize(fieldNumber, (bool) value);

-                case FieldType.String:

-                    return ComputeStringSize(fieldNumber, (string) value);

-                case FieldType.Group:

-                    return ComputeGroupSize(fieldNumber, (IMessageLite) value);

-                case FieldType.Message:

-                    return ComputeMessageSize(fieldNumber, (IMessageLite) value);

-                case FieldType.Bytes:

-                    return ComputeBytesSize(fieldNumber, (ByteString) value);

-                case FieldType.UInt32:

-                    return ComputeUInt32Size(fieldNumber, (uint) value);

-                case FieldType.SFixed32:

-                    return ComputeSFixed32Size(fieldNumber, (int) value);

-                case FieldType.SFixed64:

-                    return ComputeSFixed64Size(fieldNumber, (long) value);

-                case FieldType.SInt32:

-                    return ComputeSInt32Size(fieldNumber, (int) value);

-                case FieldType.SInt64:

-                    return ComputeSInt64Size(fieldNumber, (long) value);

-                case FieldType.Enum:

-                    if (value is System.Enum)

-                        return ComputeEnumSize(fieldNumber, ((IConvertible)value).ToInt32(CultureInfo.InvariantCulture));

-                    else

-                        return ComputeEnumSize(fieldNumber, ((IEnumLite) value).Number);

-                default:

-                    throw new ArgumentOutOfRangeException("Invalid field type " + fieldType);

-            }

-        }

-

-        /// <summary>

-        /// Compute the number of bytes that would be needed to encode a

-        /// field of arbitrary type, excluding the tag, to the stream.

-        /// </summary>

-        public static int ComputeFieldSizeNoTag(FieldType fieldType, Object value)

-        {

-            switch (fieldType)

-            {

-                case FieldType.Double:

-                    return ComputeDoubleSizeNoTag((double) value);

-                case FieldType.Float:

-                    return ComputeFloatSizeNoTag((float) value);

-                case FieldType.Int64:

-                    return ComputeInt64SizeNoTag((long) value);

-                case FieldType.UInt64:

-                    return ComputeUInt64SizeNoTag((ulong) value);

-                case FieldType.Int32:

-                    return ComputeInt32SizeNoTag((int) value);

-                case FieldType.Fixed64:

-                    return ComputeFixed64SizeNoTag((ulong) value);

-                case FieldType.Fixed32:

-                    return ComputeFixed32SizeNoTag((uint) value);

-                case FieldType.Bool:

-                    return ComputeBoolSizeNoTag((bool) value);

-                case FieldType.String:

-                    return ComputeStringSizeNoTag((string) value);

-                case FieldType.Group:

-                    return ComputeGroupSizeNoTag((IMessageLite) value);

-                case FieldType.Message:

-                    return ComputeMessageSizeNoTag((IMessageLite) value);

-                case FieldType.Bytes:

-                    return ComputeBytesSizeNoTag((ByteString) value);

-                case FieldType.UInt32:

-                    return ComputeUInt32SizeNoTag((uint) value);

-                case FieldType.SFixed32:

-                    return ComputeSFixed32SizeNoTag((int) value);

-                case FieldType.SFixed64:

-                    return ComputeSFixed64SizeNoTag((long) value);

-                case FieldType.SInt32:

-                    return ComputeSInt32SizeNoTag((int) value);

-                case FieldType.SInt64:

-                    return ComputeSInt64SizeNoTag((long) value);

-                case FieldType.Enum:

-                    if (value is System.Enum)

-                        return ComputeEnumSizeNoTag(((IConvertible)value).ToInt32(CultureInfo.InvariantCulture));

-                    else

-                        return ComputeEnumSizeNoTag(((IEnumLite) value).Number);

-                default:

-                    throw new ArgumentOutOfRangeException("Invalid field type " + fieldType);

-            }

-        }

-

-        /// <summary>

-        /// Compute the number of bytes that would be needed to encode a tag.

-        /// </summary>

-        public static int ComputeTagSize(int fieldNumber)

-        {

-            return ComputeRawVarint32Size(WireFormat.MakeTag(fieldNumber, 0));

-        }

-

-        #endregion

-

         /// <summary>

         /// Encode a 32-bit value with ZigZag encoding.

         /// </summary>