Minor simplification to std::_Bind_result helpers

	* include/std/functional (_Bind_result::__enable_if_void): Use alias
	template instead of class template.
	(_Bind_result::__disable_if_void): Likewise.
	(_Bind_result::__call): Adjust uses of __enable_if_void and
	__disable_if_void.

From-SVN: r240940

diff --git a/libstdc++-v3/ChangeLog b/libstdc++-v3/ChangeLog
index 34b7d05f3b469495cf6402ff44a2a6e9a6ba2e71..afa10f4a427fe48c297800a3ce92bf1cf7c485a3 100644 (file)
--- a/libstdc++-v3/ChangeLog
+++ b/libstdc++-v3/ChangeLog
@@ -1,5 +1,11 @@
 2016-10-10  Jonathan Wakely  <jwakely@redhat.com>
 
+       * include/std/functional (_Bind_result::__enable_if_void): Use alias
+       template instead of class template.
+       (_Bind_result::__disable_if_void): Likewise.
+       (_Bind_result::__call): Adjust uses of __enable_if_void and
+       __disable_if_void.
+
        * doc/xml/manual/intro.xml: Document DR 2296 status.
        * doc/xml/manual/status_cxx2017.xml: Update status.
        * include/bits/move.h (__addressof): Add _GLIBCXX_CONSTEXPR and

diff --git a/libstdc++-v3/include/std/functional b/libstdc++-v3/include/std/functional
index 1c7523e89afbd5a204428a5c4d420b16c80b6cc0..2587392a25cf8901e2402504dd48ce82b153575b 100644 (file)
--- a/libstdc++-v3/include/std/functional
+++ b/libstdc++-v3/include/std/functional
@@ -1000,15 +1000,17 @@ _GLIBCXX_MEM_FN_TRAITS(&&, false_type, true_type)
 
       // sfinae types
       template<typename _Res>
-       struct __enable_if_void : enable_if<is_void<_Res>::value, int> { };
+       using __enable_if_void
+         = typename enable_if<is_void<_Res>{}>::type;
+
       template<typename _Res>
-       struct __disable_if_void : enable_if<!is_void<_Res>::value, int> { };
+       using __disable_if_void
+         = typename enable_if<!is_void<_Res>{}, _Result>::type;
 
       // Call unqualified
       template<typename _Res, typename... _Args, std::size_t... _Indexes>
-       _Result
-       __call(tuple<_Args...>&& __args, _Index_tuple<_Indexes...>,
-           typename __disable_if_void<_Res>::type = 0)
+       __disable_if_void<_Res>
+       __call(tuple<_Args...>&& __args, _Index_tuple<_Indexes...>)
        {
          return _M_f(_Mu<_Bound_args>()
                      (std::get<_Indexes>(_M_bound_args), __args)...);
@@ -1016,9 +1018,8 @@ _GLIBCXX_MEM_FN_TRAITS(&&, false_type, true_type)
 
       // Call unqualified, return void
       template<typename _Res, typename... _Args, std::size_t... _Indexes>
-       void
-       __call(tuple<_Args...>&& __args, _Index_tuple<_Indexes...>,
-           typename __enable_if_void<_Res>::type = 0)
+       __enable_if_void<_Res>
+       __call(tuple<_Args...>&& __args, _Index_tuple<_Indexes...>)
        {
          _M_f(_Mu<_Bound_args>()
               (std::get<_Indexes>(_M_bound_args), __args)...);
@@ -1026,9 +1027,8 @@ _GLIBCXX_MEM_FN_TRAITS(&&, false_type, true_type)
 
       // Call as const
       template<typename _Res, typename... _Args, std::size_t... _Indexes>
-       _Result
-       __call(tuple<_Args...>&& __args, _Index_tuple<_Indexes...>,
-           typename __disable_if_void<_Res>::type = 0) const
+       __disable_if_void<_Res>
+       __call(tuple<_Args...>&& __args, _Index_tuple<_Indexes...>) const
        {
          return _M_f(_Mu<_Bound_args>()
                      (std::get<_Indexes>(_M_bound_args), __args)...);
@@ -1036,9 +1036,8 @@ _GLIBCXX_MEM_FN_TRAITS(&&, false_type, true_type)
 
       // Call as const, return void
       template<typename _Res, typename... _Args, std::size_t... _Indexes>
-       void
-       __call(tuple<_Args...>&& __args, _Index_tuple<_Indexes...>,
-           typename __enable_if_void<_Res>::type = 0) const
+       __enable_if_void<_Res>
+       __call(tuple<_Args...>&& __args, _Index_tuple<_Indexes...>) const
        {
          _M_f(_Mu<_Bound_args>()
               (std::get<_Indexes>(_M_bound_args),  __args)...);
@@ -1046,9 +1045,8 @@ _GLIBCXX_MEM_FN_TRAITS(&&, false_type, true_type)
 
       // Call as volatile
       template<typename _Res, typename... _Args, std::size_t... _Indexes>
-       _Result
-       __call(tuple<_Args...>&& __args, _Index_tuple<_Indexes...>,
-           typename __disable_if_void<_Res>::type = 0) volatile
+       __disable_if_void<_Res>
+       __call(tuple<_Args...>&& __args, _Index_tuple<_Indexes...>) volatile
        {
          return _M_f(_Mu<_Bound_args>()
                      (__volget<_Indexes>(_M_bound_args), __args)...);
@@ -1056,9 +1054,8 @@ _GLIBCXX_MEM_FN_TRAITS(&&, false_type, true_type)
 
       // Call as volatile, return void
       template<typename _Res, typename... _Args, std::size_t... _Indexes>
-       void
-       __call(tuple<_Args...>&& __args, _Index_tuple<_Indexes...>,
-           typename __enable_if_void<_Res>::type = 0) volatile
+       __enable_if_void<_Res>
+       __call(tuple<_Args...>&& __args, _Index_tuple<_Indexes...>) volatile
        {
          _M_f(_Mu<_Bound_args>()
               (__volget<_Indexes>(_M_bound_args), __args)...);
@@ -1066,9 +1063,9 @@ _GLIBCXX_MEM_FN_TRAITS(&&, false_type, true_type)
 
       // Call as const volatile
       template<typename _Res, typename... _Args, std::size_t... _Indexes>
-       _Result
-       __call(tuple<_Args...>&& __args, _Index_tuple<_Indexes...>,
-           typename __disable_if_void<_Res>::type = 0) const volatile
+       __disable_if_void<_Res>
+       __call(tuple<_Args...>&& __args,
+              _Index_tuple<_Indexes...>) const volatile
        {
          return _M_f(_Mu<_Bound_args>()
                      (__volget<_Indexes>(_M_bound_args), __args)...);
@@ -1076,10 +1073,9 @@ _GLIBCXX_MEM_FN_TRAITS(&&, false_type, true_type)
 
       // Call as const volatile, return void
       template<typename _Res, typename... _Args, std::size_t... _Indexes>
-       void
+       __enable_if_void<_Res>
        __call(tuple<_Args...>&& __args,
-              _Index_tuple<_Indexes...>,
-           typename __enable_if_void<_Res>::type = 0) const volatile
+              _Index_tuple<_Indexes...>) const volatile
        {
          _M_f(_Mu<_Bound_args>()
               (__volget<_Indexes>(_M_bound_args), __args)...);