Take cv-qualifiers on fields of class type into account when determining

whether a defaulted special member function should be deleted.

llvm-svn: 195620

clang/lib/Sema/SemaDeclCXX.cpp

@@ -4913,6 +4913,10 @@ struct SpecialMemberDeletionInfo {
     // cv-qualifiers on class members don't affect default ctor / dtor calls.
     if (CSM == Sema::CXXDefaultConstructor || CSM == Sema::CXXDestructor)
       Quals = 0;
+    // cv-qualifiers on class members affect the type of both '*this' and the
+    // argument for an assignment.
+    if (IsAssignment)
+      TQ |= Quals;
     return S.LookupSpecialMember(Class, CSM,
                                  ConstArg || (Quals & Qualifiers::Const),
                                  VolatileArg || (Quals & Qualifiers::Volatile),