When performing template argument deduction for a non-reference

conversion function when we're binding the result to a reference, drop
cv-qualifiers on the type we're referring to, since we should be
deducing a type that can be adjusted (via cv-qualification) to the
requested type. Fixes PR9336, and the remaining Boost.Assign failure.

llvm-svn: 127117

1 files changed, 8 insertions, 7 deletions

diff --git a/clang/lib/Sema/SemaTemplateDeduction.cpp b/clang/lib/Sema/SemaTemplateDeduction.cpp
index 43cbd62a635..c30c8a06162 100644
--- a/clang/lib/Sema/SemaTemplateDeduction.cpp
+++ b/clang/lib/Sema/SemaTemplateDeduction.cpp
@@ -2845,18 +2845,18 @@ Sema::DeduceTemplateArguments(FunctionTemplateDecl *FunctionTemplate,
   QualType P = Context.getCanonicalType(FromType);
   QualType A = Context.getCanonicalType(ToType);
 
-  // C++0x [temp.deduct.conv]p3:
+  // C++0x [temp.deduct.conv]p2:
   //   If P is a reference type, the type referred to by P is used for
   //   type deduction.
   if (const ReferenceType *PRef = P->getAs<ReferenceType>())
     P = PRef->getPointeeType();
 
-  // C++0x [temp.deduct.conv]p3:
-  //   If A is a reference type, the type referred to by A is used
+  // C++0x [temp.deduct.conv]p4:
+  //   [...] If A is a reference type, the type referred to by A is used
   //   for type deduction.
   if (const ReferenceType *ARef = A->getAs<ReferenceType>())
-    A = ARef->getPointeeType();
-  // C++ [temp.deduct.conv]p2:
+    A = ARef->getPointeeType().getUnqualifiedType();
+  // C++ [temp.deduct.conv]p3:
   //
   //   If A is not a reference type:
   else {
@@ -2877,9 +2877,10 @@ Sema::DeduceTemplateArguments(FunctionTemplateDecl *FunctionTemplate,
     else
       P = P.getUnqualifiedType();
 
-    // C++0x [temp.deduct.conv]p3:
+    // C++0x [temp.deduct.conv]p4:
     //   If A is a cv-qualified type, the top level cv-qualifiers of A's
-    //   type are ignored for type deduction.
+    //   type are ignored for type deduction. If A is a reference type, the type 
+    //   referred to by A is used for type deduction.
     A = A.getUnqualifiedType();
   }