Template argument deduction for references

llvm-svn: 72822

clang/lib/AST/Type.cpp

@@ -1049,6 +1049,10 @@ TemplateSpecializationType::
 anyDependentTemplateArguments(const TemplateArgument *Args, unsigned NumArgs) {
   for (unsigned Idx = 0; Idx < NumArgs; ++Idx) {
     switch (Args[Idx].getKind()) {
+    case TemplateArgument::Null:
+      assert(false && "Should not have a NULL template argument");
+      break;
+        
     case TemplateArgument::Type:
       if (Args[Idx].getAsType()->isDependentType())
         return true;

clang/lib/Sema/SemaTemplateDeduction.cpp

@@ -66,15 +66,42 @@ static bool DeduceTemplateArguments(ASTContext &Context, QualType Param,
   if (Param.getCVRQualifiers() != Arg.getCVRQualifiers())
     return false;
 
-  if (const PointerType *PointerParam = Param->getAsPointerType()) {
-    const PointerType *PointerArg = Arg->getAsPointerType();
-    if (!PointerArg)
-      return false;
+  switch (Param->getTypeClass()) {
+    case Type::Pointer: {
+      const PointerType *PointerArg = Arg->getAsPointerType();
+      if (!PointerArg)
+        return false;
+      
+      return DeduceTemplateArguments(Context,
+                                   cast<PointerType>(Param)->getPointeeType(),
+                                     PointerArg->getPointeeType(),
+                                     Deduced);
+    }
+      
+    case Type::LValueReference: {
+      const LValueReferenceType *ReferenceArg = Arg->getAsLValueReferenceType();
+      if (!ReferenceArg)
+        return false;
+      
+      return DeduceTemplateArguments(Context,
+                           cast<LValueReferenceType>(Param)->getPointeeType(),
+                                     ReferenceArg->getPointeeType(),
+                                     Deduced);
+    }
 
-    return DeduceTemplateArguments(Context,
-                                   PointerParam->getPointeeType(),
-                                   PointerArg->getPointeeType(),
-                                   Deduced);
+    case Type::RValueReference: {
+      const RValueReferenceType *ReferenceArg = Arg->getAsRValueReferenceType();
+      if (!ReferenceArg)
+        return false;
+      
+      return DeduceTemplateArguments(Context,
+                           cast<RValueReferenceType>(Param)->getPointeeType(),
+                                     ReferenceArg->getPointeeType(),
+                                     Deduced);
+    }
+      
+    default:
+      break;
   }
 
   // FIXME: Many more cases to go (to go).

clang/test/SemaTemplate/temp_class_spec.cpp

@@ -19,6 +19,19 @@ int array1[is_pointer<int*>::value? 1 : -1];
 int array2[is_pointer<const int*>::value? 1 : -1]; // expected-error{{partial ordering}} \
 // expected-error{{negative}}
 
+template<typename T>
+struct is_lvalue_reference {
+  static const bool value = false;
+};
+
+template<typename T>
+struct is_lvalue_reference<T&> {
+  static const bool value = true;
+};
+
+int lvalue_ref0[is_lvalue_reference<int>::value? -1 : 1];
+int lvalue_ref1[is_lvalue_reference<const int&>::value? 1 : -1];
+
 template<typename T, typename U>
 struct is_same {
   static const bool value = false;