Add member template 'Type::getAs<T>', which converts a Type* to a respective T*.
This method is intended to eventually replace the individual
Type::getAsXXXType<> methods.

The motivation behind this change is twofold:

1) Reduce redundant implementations of Type::getAsXXXType() methods. Most of
them are basically copy-and-paste.

2) By centralizing the implementation of the getAs<Type> logic we can more
smoothly move over to Doug Gregor's proposed canonical type smart pointer
scheme.

Along with this patch:

a) Removed 'Type::getAsPointerType()'; now clients use getAs<PointerType>.
b) Removed 'Type::getAsBlockPointerTypE()'; now clients use getAs<BlockPointerType>.



git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@76098 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Sema/SemaTemplate.cpp b/lib/Sema/SemaTemplate.cpp
index 568d68c..85d3867 100644
--- a/lib/Sema/SemaTemplate.cpp
+++ b/lib/Sema/SemaTemplate.cpp
@@ -225,8 +225,8 @@
   if (T->isIntegralType() || T->isEnumeralType() ||
       //   -- pointer to object or pointer to function, 
       (T->isPointerType() && 
-       (T->getAsPointerType()->getPointeeType()->isObjectType() ||
-        T->getAsPointerType()->getPointeeType()->isFunctionType())) ||
+       (T->getAs<PointerType>()->getPointeeType()->isObjectType() ||
+        T->getAs<PointerType>()->getPointeeType()->isFunctionType())) ||
       //   -- reference to object or reference to function, 
       T->isReferenceType() ||
       //   -- pointer to member.
@@ -1648,7 +1648,7 @@
       //    function is selected from the set (13.4).
       // In C++0x, any std::nullptr_t value can be converted.
       (ParamType->isPointerType() &&
-       ParamType->getAsPointerType()->getPointeeType()->isFunctionType()) ||
+       ParamType->getAs<PointerType>()->getPointeeType()->isFunctionType()) ||
       // -- For a non-type template-parameter of type reference to
       //    function, no conversions apply. If the template-argument
       //    represents a set of overloaded functions, the matching
@@ -1721,7 +1721,7 @@
     //      object, qualification conversions (4.4) and the
     //      array-to-pointer conversion (4.2) are applied.
     // C++0x also allows a value of std::nullptr_t.
-    assert(ParamType->getAsPointerType()->getPointeeType()->isObjectType() &&
+    assert(ParamType->getAs<PointerType>()->getPointeeType()->isObjectType() &&
            "Only object pointers allowed here");
 
     if (ArgType->isNullPtrType()) {