This is a simplified (and superior) implementation of __invoke, __invokable and __invoke_of. It is superior in that __invoke now handles reference qualified member functions whereas the previous implementation did not. And it simply has less infrastructure in its implementation. I'm still learning how to program in C++11 (and probably will be for a long time). This change does not impact the behavior we're seeing in http://llvm.org/bugs/show_bug.cgi?id=9975

llvm-svn: 131761

1 files changed, 31 insertions, 145 deletions

diff --git a/libcxx/include/__functional_base b/libcxx/include/__functional_base
index 518c9b7afe6..caf0093eb81 100644
--- a/libcxx/include/__functional_base
+++ b/libcxx/include/__functional_base
@@ -281,169 +281,55 @@ struct __weak_result_type<_R (_C::*)(_A1, _A2, _A3...) const volatile>
 
 // __invoke
 
-// first bullet
+// bullets 1 and 2
 
-template <class _R, class _T, class _T1, class ..._Param, class ..._Arg>
+template <class _F, class _A0, class ..._Args>
 inline _LIBCPP_INLINE_VISIBILITY
-typename enable_if
-<
-    sizeof...(_Param) == sizeof...(_Arg) &&
-    is_base_of<_T, typename remove_reference<_T1>::type>::value,
-    _R
->::type
-__invoke(_R (_T::*__f)(_Param...), _T1&& __t1, _Arg&& ...__arg)
-{
-    return (_STD::forward<_T>(__t1).*__f)(_STD::forward<_Arg>(__arg)...);
-}
-
-template <class _R, class _T, class _T1, class ..._Param, class ..._Arg>
-inline _LIBCPP_INLINE_VISIBILITY
-typename enable_if
-<
-    sizeof...(_Param) == sizeof...(_Arg) &&
-    is_base_of<_T, typename remove_reference<_T1>::type>::value,
-    _R
->::type
-__invoke(_R (_T::*__f)(_Param...) const, _T1&& __t1, _Arg&& ...__arg)
-{
-    return (_STD::forward<const _T>(__t1).*__f)(_STD::forward<_Arg>(__arg)...);
-}
-
-template <class _R, class _T, class _T1, class ..._Param, class ..._Arg>
-inline _LIBCPP_INLINE_VISIBILITY
-typename enable_if
-<
-    sizeof...(_Param) == sizeof...(_Arg) &&
-    is_base_of<_T, typename remove_reference<_T1>::type>::value,
-    _R
->::type
-__invoke(_R (_T::*__f)(_Param...) volatile, _T1&& __t1, _Arg&& ...__arg)
-{
-    return (_STD::forward<volatile _T>(__t1).*__f)(_STD::forward<_Arg>(__arg)...);
-}
-
-template <class _R, class _T, class _T1, class ..._Param, class ..._Arg>
-inline _LIBCPP_INLINE_VISIBILITY
-typename enable_if
-<
-    sizeof...(_Param) == sizeof...(_Arg) &&
-    is_base_of<_T, typename remove_reference<_T1>::type>::value,
-    _R
->::type
-__invoke(_R (_T::*__f)(_Param...) const volatile, _T1&& __t1, _Arg&& ...__arg)
-{
-    return (_STD::forward<const volatile _T>(__t1).*__f)(_STD::forward<_Arg>(__arg)...);
-}
-
-// second bullet
-
-template <class _R, class _T, class _T1, class ..._Param, class ..._Arg>
-inline _LIBCPP_INLINE_VISIBILITY
-typename enable_if
-<
-    sizeof...(_Param) == sizeof...(_Arg) &&
-    !is_base_of<_T, typename remove_reference<_T1>::type>::value,
-    _R
->::type
-__invoke(_R (_T::*__f)(_Param...), _T1&& __t1, _Arg&& ...__arg)
-{
-    return ((*_STD::forward<_T1>(__t1)).*__f)(_STD::forward<_Arg>(__arg)...);
-}
-
-template <class _R, class _T, class _T1, class ..._Param, class ..._Arg>
-inline _LIBCPP_INLINE_VISIBILITY
-typename enable_if
-<
-    sizeof...(_Param) == sizeof...(_Arg) &&
-    !is_base_of<_T, typename remove_reference<_T1>::type>::value,
-    _R
->::type
-__invoke(_R (_T::*__f)(_Param...) const, _T1&& __t1, _Arg&& ...__arg)
-{
-    return ((*_STD::forward<_T1>(__t1)).*__f)(_STD::forward<_Arg>(__arg)...);
-}
-
-template <class _R, class _T, class _T1, class ..._Param, class ..._Arg>
-inline _LIBCPP_INLINE_VISIBILITY
-typename enable_if
-<
-    sizeof...(_Param) == sizeof...(_Arg) &&
-    !is_base_of<_T, typename remove_reference<_T1>::type>::value,
-    _R
->::type
-__invoke(_R (_T::*__f)(_Param...) volatile, _T1&& __t1, _Arg&& ...__arg)
-{
-    return ((*_STD::forward<_T1>(__t1)).*__f)(_STD::forward<_Arg>(__arg)...);
+auto
+__invoke(_F&& __f, _A0&& __a0, _Args&& ...__args)
+    -> decltype((_STD::forward<_A0>(__a0).*__f)(_STD::forward<_Args>(__args)...))
+{
+    return (_STD::forward<_A0>(__a0).*__f)(_STD::forward<_Args>(__args)...);
 }
 
-template <class _R, class _T, class _T1, class ..._Param, class ..._Arg>
+template <class _F, class _A0, class ..._Args>
 inline _LIBCPP_INLINE_VISIBILITY
-typename enable_if
-<
-    sizeof...(_Param) == sizeof...(_Arg) &&
-    !is_base_of<_T, typename remove_reference<_T1>::type>::value,
-    _R
->::type
-__invoke(_R (_T::*__f)(_Param...) const volatile, _T1&& __t1, _Arg&& ...__arg)
-{
-    return ((*_STD::forward<_T1>(__t1)).*__f)(_STD::forward<_Arg>(__arg)...);
+auto
+__invoke(_F&& __f, _A0&& __a0, _Args&& ...__args)
+    -> decltype(((*_STD::forward<_A0>(__a0)).*__f)(_STD::forward<_Args>(__args)...))
+{
+    return ((*_STD::forward<_A0>(__a0)).*__f)(_STD::forward<_Args>(__args)...);
 }
 
-// third bullet
+// bullets 3 and 4
 
-template <class _R, class _T, class _T1>
+template <class _F, class _A0>
 inline _LIBCPP_INLINE_VISIBILITY
-typename enable_if
-<
-    is_base_of<_T, typename remove_reference<_T1>::type>::value,
-    typename __apply_cv<_T1, _R>::type&&
->::type
-__invoke(_R _T::* __f, _T1&& __t1)
-{
-    return _STD::forward<_T1>(__t1).*__f;
-}
-
-// forth bullet
-
-template <class _T1, class _R, bool>
-struct __4th_helper
+auto
+__invoke(_F&& __f, _A0&& __a0)
+    -> decltype(_STD::forward<_A0>(__a0).*__f)
 {
-};
-
-template <class _T1, class _R>
-struct __4th_helper<_T1, _R, true>
-{
-    typedef typename __apply_cv<decltype(*_STD::declval<_T1>()), _R>::type type;
-};
-
-template <class _R, class _T, class _T1>
-inline _LIBCPP_INLINE_VISIBILITY
-typename __4th_helper<_T1, _R,
-                      !is_base_of<_T,
-                                  typename remove_reference<_T1>::type
-                                 >::value
-                     >::type&&
-__invoke(_R _T::* __f, _T1&& __t1)
-{
-    return (*_STD::forward<_T1>(__t1)).*__f;
+    return _STD::forward<_A0>(__a0).*__f;
 }
 
-// fifth bullet
-
-template <class _R, class ..._Param, class ..._Args>
+template <class _F, class _A0>
 inline _LIBCPP_INLINE_VISIBILITY
-_R
-__invoke(_R (*__f)(_Param...), _Args&& ...__args)
+auto
+__invoke(_F&& __f, _A0&& __a0)
+    -> decltype((*_STD::forward<_A0>(__a0)).*__f)
 {
-    return __f(_STD::forward<_Args>(__args)...);
+    return (*_STD::forward<_A0>(__a0)).*__f;
 }
 
-template <class _F, class ..._T>
+// bullet 5
+
+template <class _F, class ..._Args>
 inline _LIBCPP_INLINE_VISIBILITY
-typename __invoke_of<_F, _T...>::type
-__invoke(_F&& __f, _T&& ...__t)
+auto
+__invoke(_F&& __f, _Args&& ...__args)
+    -> decltype(_STD::forward<_F>(__f)(_STD::forward<_Args>(__args)...))
 {
-    return _STD::forward<_F>(__f)(_STD::forward<_T>(__t)...);
+    return _STD::forward<_F>(__f)(_STD::forward<_Args>(__args)...);
 }
 
 template <class _Tp, class ..._Args>