From 00f512ebdf3e40969b135c4241421d218d37a71f Mon Sep 17 00:00:00 2001
From: Eric Fiselier <eric@efcs.ca>
Date: Wed, 22 Jul 2015 22:43:27 +0000
Subject: [PATCH] Merge C++03 and C++11 implementations of mem_fn and __mem_fn.

The implementation of mem_fn doesn't actually require any  C++11 support.
For some reason there were 17 overloads for mem_fn in C++03 when only one
is needed. This patch removes the extra overloads and uses the same implementation
of mem_fn in C++03 and C++11.

__mem_fn does require variadics to implement the call operator. Instead of
having two entirely different implementations of the __mem_fn struct, this patch
uses the same __mem_fn struct but provides different call operators when
variadics are not available.

The only thing left in <__functional_03> is the C++03 implementation of
std::function.

llvm-svn: 242959
---
 libcxx/include/__functional_03 | 179 -----------------------------------------
 libcxx/include/functional      |  55 ++++++++-----
 2 files changed, 35 insertions(+), 199 deletions(-)

diff --git a/libcxx/include/__functional_03 b/libcxx/include/__functional_03
index bf55e23..56a8475 100644
--- a/libcxx/include/__functional_03
+++ b/libcxx/include/__functional_03
@@ -17,185 +17,6 @@
 #pragma GCC system_header
 #endif
 
-template <class _Tp>
-class __mem_fn
-    : public __weak_result_type<_Tp>
-{
-public:
-    // types
-    typedef _Tp type;
-private:
-    type __f_;
-
-public:
-    _LIBCPP_INLINE_VISIBILITY __mem_fn(type __f) : __f_(__f) {}
-
-    // invoke
-
-    typename __invoke_return<type>::type
-       operator() () const
-       {
-           return __invoke(__f_);
-       }
-
-    template <class _A0>
-       typename __invoke_return0<type, _A0>::type
-          operator() (_A0& __a0) const
-          {
-              return __invoke(__f_, __a0);
-          }
-
-    template <class _A0, class _A1>
-       typename __invoke_return1<type, _A0, _A1>::type
-          operator() (_A0& __a0, _A1& __a1) const
-          {
-              return __invoke(__f_, __a0, __a1);
-          }
-
-    template <class _A0, class _A1, class _A2>
-       typename __invoke_return2<type, _A0, _A1, _A2>::type
-          operator() (_A0& __a0, _A1& __a1, _A2& __a2) const
-          {
-              return __invoke(__f_, __a0, __a1, __a2);
-          }
-};
-
-template<class _Rp, class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY
-__mem_fn<_Rp _Tp::*>
-mem_fn(_Rp _Tp::* __pm)
-{
-    return __mem_fn<_Rp _Tp::*>(__pm);
-}
-
-template<class _Rp, class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY
-__mem_fn<_Rp (_Tp::*)()>
-mem_fn(_Rp (_Tp::* __pm)())
-{
-    return __mem_fn<_Rp (_Tp::*)()>(__pm);
-}
-
-template<class _Rp, class _Tp, class _A0>
-inline _LIBCPP_INLINE_VISIBILITY
-__mem_fn<_Rp (_Tp::*)(_A0)>
-mem_fn(_Rp (_Tp::* __pm)(_A0))
-{
-    return __mem_fn<_Rp (_Tp::*)(_A0)>(__pm);
-}
-
-template<class _Rp, class _Tp, class _A0, class _A1>
-inline _LIBCPP_INLINE_VISIBILITY
-__mem_fn<_Rp (_Tp::*)(_A0, _A1)>
-mem_fn(_Rp (_Tp::* __pm)(_A0, _A1))
-{
-    return __mem_fn<_Rp (_Tp::*)(_A0, _A1)>(__pm);
-}
-
-template<class _Rp, class _Tp, class _A0, class _A1, class _A2>
-inline _LIBCPP_INLINE_VISIBILITY
-__mem_fn<_Rp (_Tp::*)(_A0, _A1, _A2)>
-mem_fn(_Rp (_Tp::* __pm)(_A0, _A1, _A2))
-{
-    return __mem_fn<_Rp (_Tp::*)(_A0, _A1, _A2)>(__pm);
-}
-
-template<class _Rp, class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY
-__mem_fn<_Rp (_Tp::*)() const>
-mem_fn(_Rp (_Tp::* __pm)() const)
-{
-    return __mem_fn<_Rp (_Tp::*)() const>(__pm);
-}
-
-template<class _Rp, class _Tp, class _A0>
-inline _LIBCPP_INLINE_VISIBILITY
-__mem_fn<_Rp (_Tp::*)(_A0) const>
-mem_fn(_Rp (_Tp::* __pm)(_A0) const)
-{
-    return __mem_fn<_Rp (_Tp::*)(_A0) const>(__pm);
-}
-
-template<class _Rp, class _Tp, class _A0, class _A1>
-inline _LIBCPP_INLINE_VISIBILITY
-__mem_fn<_Rp (_Tp::*)(_A0, _A1) const>
-mem_fn(_Rp (_Tp::* __pm)(_A0, _A1) const)
-{
-    return __mem_fn<_Rp (_Tp::*)(_A0, _A1) const>(__pm);
-}
-
-template<class _Rp, class _Tp, class _A0, class _A1, class _A2>
-inline _LIBCPP_INLINE_VISIBILITY
-__mem_fn<_Rp (_Tp::*)(_A0, _A1, _A2) const>
-mem_fn(_Rp (_Tp::* __pm)(_A0, _A1, _A2) const)
-{
-    return __mem_fn<_Rp (_Tp::*)(_A0, _A1, _A2) const>(__pm);
-}
-
-template<class _Rp, class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY
-__mem_fn<_Rp (_Tp::*)() volatile>
-mem_fn(_Rp (_Tp::* __pm)() volatile)
-{
-    return __mem_fn<_Rp (_Tp::*)() volatile>(__pm);
-}
-
-template<class _Rp, class _Tp, class _A0>
-inline _LIBCPP_INLINE_VISIBILITY
-__mem_fn<_Rp (_Tp::*)(_A0) volatile>
-mem_fn(_Rp (_Tp::* __pm)(_A0) volatile)
-{
-    return __mem_fn<_Rp (_Tp::*)(_A0) volatile>(__pm);
-}
-
-template<class _Rp, class _Tp, class _A0, class _A1>
-inline _LIBCPP_INLINE_VISIBILITY
-__mem_fn<_Rp (_Tp::*)(_A0, _A1) volatile>
-mem_fn(_Rp (_Tp::* __pm)(_A0, _A1) volatile)
-{
-    return __mem_fn<_Rp (_Tp::*)(_A0, _A1) volatile>(__pm);
-}
-
-template<class _Rp, class _Tp, class _A0, class _A1, class _A2>
-inline _LIBCPP_INLINE_VISIBILITY
-__mem_fn<_Rp (_Tp::*)(_A0, _A1, _A2) volatile>
-mem_fn(_Rp (_Tp::* __pm)(_A0, _A1, _A2) volatile)
-{
-    return __mem_fn<_Rp (_Tp::*)(_A0, _A1, _A2) volatile>(__pm);
-}
-
-template<class _Rp, class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY
-__mem_fn<_Rp (_Tp::*)() const volatile>
-mem_fn(_Rp (_Tp::* __pm)() const volatile)
-{
-    return __mem_fn<_Rp (_Tp::*)() const volatile>(__pm);
-}
-
-template<class _Rp, class _Tp, class _A0>
-inline _LIBCPP_INLINE_VISIBILITY
-__mem_fn<_Rp (_Tp::*)(_A0) const volatile>
-mem_fn(_Rp (_Tp::* __pm)(_A0) const volatile)
-{
-    return __mem_fn<_Rp (_Tp::*)(_A0) const volatile>(__pm);
-}
-
-template<class _Rp, class _Tp, class _A0, class _A1>
-inline _LIBCPP_INLINE_VISIBILITY
-__mem_fn<_Rp (_Tp::*)(_A0, _A1) const volatile>
-mem_fn(_Rp (_Tp::* __pm)(_A0, _A1) const volatile)
-{
-    return __mem_fn<_Rp (_Tp::*)(_A0, _A1) const volatile>(__pm);
-}
-
-template<class _Rp, class _Tp, class _A0, class _A1, class _A2>
-inline _LIBCPP_INLINE_VISIBILITY
-__mem_fn<_Rp (_Tp::*)(_A0, _A1, _A2) const volatile>
-mem_fn(_Rp (_Tp::* __pm)(_A0, _A1, _A2) const volatile)
-{
-    return __mem_fn<_Rp (_Tp::*)(_A0, _A1, _A2) const volatile>(__pm);
-}
-
 namespace __function {
 
 template<class _Fp> class __base;
diff --git a/libcxx/include/functional b/libcxx/include/functional
index 2c4a96e..939486f 100644
--- a/libcxx/include/functional
+++ b/libcxx/include/functional
@@ -1238,8 +1238,6 @@ mem_fun_ref(_Sp (_Tp::*__f)(_Ap) const)
 //                                MEMFUN
 //==============================================================================
 
-#ifndef _LIBCPP_HAS_NO_VARIADICS
-
 template <class _Tp>
 class __mem_fn
     : public __weak_result_type<_Tp>
@@ -1253,14 +1251,38 @@ private:
 public:
     _LIBCPP_INLINE_VISIBILITY __mem_fn(type __f) : __f_(__f) {}
 
+#ifndef _LIBCPP_HAS_NO_VARIADICS
     // invoke
     template <class... _ArgTypes>
-       _LIBCPP_INLINE_VISIBILITY
-       typename __invoke_return<type, _ArgTypes...>::type
-          operator() (_ArgTypes&&... __args) const
-          {
-              return __invoke(__f_, _VSTD::forward<_ArgTypes>(__args)...);
-          }
+    _LIBCPP_INLINE_VISIBILITY
+    typename __invoke_return<type, _ArgTypes...>::type
+    operator() (_ArgTypes&&... __args) const {
+        return __invoke(__f_, _VSTD::forward<_ArgTypes>(__args)...);
+    }
+#else
+    typename __invoke_return<type>::type
+    operator() () const {
+        return __invoke(__f_);
+    }
+
+    template <class _A0>
+    typename __invoke_return0<type, _A0>::type
+    operator() (_A0& __a0) const {
+        return __invoke(__f_, __a0);
+    }
+
+    template <class _A0, class _A1>
+    typename __invoke_return1<type, _A0, _A1>::type
+    operator() (_A0& __a0, _A1& __a1) const {
+        return __invoke(__f_, __a0, __a1);
+    }
+
+    template <class _A0, class _A1, class _A2>
+    typename __invoke_return2<type, _A0, _A1, _A2>::type
+    operator() (_A0& __a0, _A1& __a1, _A2& __a2) const {
+        return __invoke(__f_, __a0, __a1, __a2);
+    }
+#endif
 };
 
 template<class _Rp, class _Tp>
@@ -1271,8 +1293,6 @@ mem_fn(_Rp _Tp::* __pm)
     return __mem_fn<_Rp _Tp::*>(__pm);
 }
 
-#endif // _LIBCPP_HAS_NO_VARIADICS
-
 ////////////////////////////////////////////////////////////////////////////////
 //                                FUNCTION
 //==============================================================================
@@ -1860,7 +1880,11 @@ void
 swap(function<_Rp(_ArgTypes...)>& __x, function<_Rp(_ArgTypes...)>& __y) _NOEXCEPT
 {return __x.swap(__y);}
 
-#endif // _LIBCPP_HAS_NO_VARIADICS
+#else // _LIBCPP_HAS_NO_VARIADICS
+
+#include <__functional_03>
+
+#endif
 
 ////////////////////////////////////////////////////////////////////////////////
 //                                  BIND
@@ -2479,15 +2503,6 @@ invoke(_Fn&& __f, _Args&&... __args) {
 
 // struct hash<T*> in <memory>
 
-
-////////////////////////////////////////////////////////////////////////////////
-//                            FUNCTIONAL 03
-//==============================================================================
-
-#ifdef _LIBCPP_HAS_NO_VARIADICS
-#include <__functional_03>
-#endif
-
 _LIBCPP_END_NAMESPACE_STD
 
 #endif  // _LIBCPP_FUNCTIONAL
-- 
2.7.4