From 71e699dda5442545e3335f8c07de27c860fe2046 Mon Sep 17 00:00:00 2001
From: Marshall Clow <mclow.lists@gmail.com>
Date: Mon, 10 Feb 2014 17:40:28 +0000
Subject: [PATCH] Fix for PR17606 - result_of (and INVOKE) works incorrectly
 for member function pointers with ref qualifiers. Also a drive-by fix for
 common_type in C++03 mode. Thanks to Michel Morin for the bug report and the
 proposed fix.

git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@201101 91177308-0d34-0410-b5e6-96231b3b80d8
---
 include/type_traits                           |  6 +--
 .../func.require/invoke.pass.cpp              | 50 +++++++++++++++++++
 .../meta.trans.other/result_of.pass.cpp       | 18 +++++++
 3 files changed, 71 insertions(+), 3 deletions(-)
 create mode 100644 test/utilities/function.objects/func.require/invoke.pass.cpp

diff --git a/include/type_traits b/include/type_traits
index 04b4dd48..3e3d8b7b 100644
--- a/include/type_traits
+++ b/include/type_traits
@@ -1385,7 +1385,7 @@ template <class _Tp>
 struct _LIBCPP_TYPE_VIS_ONLY common_type<_Tp, void, void>
 {
 public:
-    typedef _Tp type;
+    typedef typename decay<_Tp>::type type;
 };
 
 template <class _Tp, class _Up>
@@ -3079,7 +3079,7 @@ template <class _Fp, class _A0, class ..._Args,
             class = typename enable_if
             <
                 is_member_function_pointer<typename remove_reference<_Fp>::type>::value &&
-                is_base_of<typename __member_pointer_traits<typename remove_reference<_Fp>::type>::_ClassType,
+                is_base_of<typename remove_reference<typename __member_pointer_traits<typename remove_reference<_Fp>::type>::_ClassType>::type,
                            typename remove_reference<_A0>::type>::value
             >::type
          >
@@ -3092,7 +3092,7 @@ template <class _Fp, class _A0, class ..._Args,
             class = typename enable_if
             <
                 is_member_function_pointer<typename remove_reference<_Fp>::type>::value &&
-                !is_base_of<typename __member_pointer_traits<typename remove_reference<_Fp>::type>::_ClassType,
+                !is_base_of<typename remove_reference<typename __member_pointer_traits<typename remove_reference<_Fp>::type>::_ClassType>::type,
                            typename remove_reference<_A0>::type>::value
             >::type
          >
diff --git a/test/utilities/function.objects/func.require/invoke.pass.cpp b/test/utilities/function.objects/func.require/invoke.pass.cpp
new file mode 100644
index 00000000..25681630
--- /dev/null
+++ b/test/utilities/function.objects/func.require/invoke.pass.cpp
@@ -0,0 +1,50 @@
+//===----------------------------------------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+// [func.require]
+
+// INVOKE
+#if __cplusplus < 201103L
+int main () {}      // no __invoke in C++03
+#else
+
+#include <type_traits>
+
+template <typename T, int N>
+struct Array
+{
+    typedef T type[N];
+};
+
+struct Type
+{
+    Array<char, 1>::type& f1();
+    Array<char, 2>::type& f2() const;
+    
+    Array<char, 1>::type& g1()        &;
+    Array<char, 2>::type& g2() const  &;
+#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
+    Array<char, 3>::type& g3()       &&;
+    Array<char, 4>::type& g4() const &&;
+#endif
+};
+
+int main()
+{
+    static_assert(sizeof(std::__invoke(&Type::f1, std::declval<Type        >())) == 1, "");
+    static_assert(sizeof(std::__invoke(&Type::f2, std::declval<Type const  >())) == 2, "");
+    
+    static_assert(sizeof(std::__invoke(&Type::g1, std::declval<Type       &>())) == 1, "");
+    static_assert(sizeof(std::__invoke(&Type::g2, std::declval<Type const &>())) == 2, "");
+#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
+    static_assert(sizeof(std::__invoke(&Type::g3, std::declval<Type      &&>())) == 3, "");
+    static_assert(sizeof(std::__invoke(&Type::g4, std::declval<Type const&&>())) == 4, "");
+#endif
+}
+#endif
diff --git a/test/utilities/meta/meta.trans/meta.trans.other/result_of.pass.cpp b/test/utilities/meta/meta.trans/meta.trans.other/result_of.pass.cpp
index 368a3eb5..bf44c340 100644
--- a/test/utilities/meta/meta.trans/meta.trans.other/result_of.pass.cpp
+++ b/test/utilities/meta/meta.trans/meta.trans.other/result_of.pass.cpp
@@ -34,6 +34,8 @@ struct wat
     void foo();
 };
 
+struct F {};
+
 template <class T, class U>
 void test_result_of_imp()
 {
@@ -55,6 +57,14 @@ int main()
     test_result_of_imp<PMD(S), char&&> ();
 #endif
     test_result_of_imp<PMD(const S*), const char&> ();
+#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
+    test_result_of_imp<int (F::* (F       &)) ()       &, int> ();
+    test_result_of_imp<int (F::* (F       &)) () const &, int> ();
+    test_result_of_imp<int (F::* (F const &)) () const &, int> ();
+    test_result_of_imp<int (F::* (F      &&)) ()      &&, int> ();
+    test_result_of_imp<int (F::* (F      &&)) () const&&, int> ();
+    test_result_of_imp<int (F::* (F const&&)) () const&&, int> ();
+#endif
 #ifndef _LIBCPP_HAS_NO_TEMPLATE_ALIASES
     using type1 = std::result_of<decltype(&wat::foo)(wat)>::type;
 #endif
@@ -74,6 +84,14 @@ int main()
     static_assert((std::is_same<std::result_of<PMD(S)>::type, char&&>::value), "Error!");
 #endif
     static_assert((std::is_same<std::result_of<PMD(const S*)>::type, const char&>::value), "Error!");
+#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
+    static_assert((std::is_same<std::result_of<int (F::* (F       &)) ()       &>::type, int>::value), "Error!");
+    static_assert((std::is_same<std::result_of<int (F::* (F       &)) () const &>::type, int>::value), "Error!");
+    static_assert((std::is_same<std::result_of<int (F::* (F const &)) () const &>::type, int>::value), "Error!");
+    static_assert((std::is_same<std::result_of<int (F::* (F      &&)) ()      &&>::type, int>::value), "Error!");
+    static_assert((std::is_same<std::result_of<int (F::* (F      &&)) () const&&>::type, int>::value), "Error!");
+    static_assert((std::is_same<std::result_of<int (F::* (F const&&)) () const&&>::type, int>::value), "Error!");
+#endif
 #ifndef _LIBCPP_HAS_NO_TEMPLATE_ALIASES
     using type = std::result_of<decltype(&wat::foo)(wat)>::type;
 #endif