Sema: As of MSVC 2015, a user-declared move operation causes the deletion of both copy operations.

[rnk]

Nice, lgtm

clang/lib/Sema/SemaDeclCXX.cpp

bool Sema::ShouldDeleteSpecialMember(CXXMethodDecl *MD, CXXSpecialMember CSM,
   // C++11 [class.copy]p7, p18:
   //   If the class definition declares a move constructor or move assignment
   //   operator, an implicitly declared copy constructor or copy assignment
   //   operator is defined as deleted.
   if (MD->isImplicit() &&
       (CSM == CXXCopyConstructor || CSM == CXXCopyAssignment)) {
     CXXMethodDecl *UserDeclaredMove = nullptr;
 
-    // In Microsoft mode, a user-declared move only causes the deletion of the
-    // corresponding copy operation, not both copy operations.
+    // In Microsoft mode up to MSVC 2013, a user-declared move only causes the
+    // deletion of the corresponding copy operation, not both copy operations.
+    // MSVC 2015 has adopted the standards conforming behavior.
+    bool DeletesOnlyMatchingCopy =
+        getLangOpts().MSVCCompat &&
+        !getLangOpts().isCompatibleWithMSVC(LangOptions::MSVC2015);
+
     if (RD->hasUserDeclaredMoveConstructor() &&
-        (!getLangOpts().MSVCCompat || CSM == CXXCopyConstructor)) {
+        (!DeletesOnlyMatchingCopy || CSM == CXXCopyConstructor)) {
       if (!Diagnose) return true;
 
       // Find any user-declared move constructor.
       for (auto *I : RD->ctors()) {
         if (I->isMoveConstructor()) {
           UserDeclaredMove = I;
           break;
         }
       }
       assert(UserDeclaredMove);
     } else if (RD->hasUserDeclaredMoveAssignment() &&
-               (!getLangOpts().MSVCCompat || CSM == CXXCopyAssignment)) {
+               (!DeletesOnlyMatchingCopy || CSM == CXXCopyAssignment)) {
       if (!Diagnose) return true;
 
       // Find any user-declared move assignment operator.
       for (auto *I : RD->methods()) {
         if (I->isMoveAssignmentOperator()) {
           UserDeclaredMove = I;
           break;
         }

clang/test/SemaCXX/MicrosoftCompatibility.cpp

a0:
   return 0;
 }
   
 }
 
 namespace PR11826 {
   struct pair {
     pair(int v) { }
+#if _MSC_VER >= 1900
+    void operator=(pair&& rhs) { } // expected-note {{copy constructor is implicitly deleted because 'pair' has a user-declared move assignment operator}}
+#else
     void operator=(pair&& rhs) { }
+#endif
   };
   void f() {
     pair p0(3);
+#if _MSC_VER >= 1900
+    pair p = p0; // expected-error {{call to implicitly-deleted copy constructor of 'PR11826::pair'}}
+#else
     pair p = p0;
+#endif
   }
 }
 
 namespace PR11826_for_symmetry {
   struct pair {
     pair(int v) { }
+#if _MSC_VER >= 1900
+    pair(pair&& rhs) { } // expected-note {{copy assignment operator is implicitly deleted because 'pair' has a user-declared move constructor}}
+#else
     pair(pair&& rhs) { }
+#endif
   };
   void f() {
     pair p0(3);
     pair p(4);
+#if _MSC_VER >= 1900
+    p = p0; // expected-error {{object of type 'PR11826_for_symmetry::pair' cannot be assigned because its copy assignment operator is implicitly deleted}}
+#else
     p = p0;
+#endif
   }
 }
 
 namespace ms_using_declaration_bug {
 
 class A {
 public: 
   int f();