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| author | Jonathan Wakely <jwakely@redhat.com> | 2015-12-11 21:45:51 +0000 |
|---|---|---|
| committer | Jonathan Wakely <redi@gcc.gnu.org> | 2015-12-11 21:45:51 +0000 |
| commit | f3d7dd52a6e8c379f7f90cb547e2cd186fa07653 (patch) | |
| tree | 8333e60d67980807a518e0b427303c908fcb7045 /libstdc++-v3/include/std/functional | |
| parent | b49e35a94a6427541e3beb197426d74ee005b43c (diff) | |
| download | gcc-f3d7dd52a6e8c379f7f90cb547e2cd186fa07653.zip gcc-f3d7dd52a6e8c379f7f90cb547e2cd186fa07653.tar.gz gcc-f3d7dd52a6e8c379f7f90cb547e2cd186fa07653.tar.bz2 | |
Fix std::invoke support for reference_wrappers
PR libstdc++/59768
* include/std/functional (_Unwrap, __invfwd): Define.
(__invoke_impl): Remove reference_wrapper overloads and use __invfwd.
* include/std/type_traits (__result_of_memobj, __result_of_memfun):
Add partial specializations for const reference_wrappers and simplify.
* testsuite/20_util/bind/ref_neg.cc: Use dg-excess-errors.
* testsuite/20_util/function_objects/invoke/59768.cc: New.
From-SVN: r231574
Diffstat (limited to 'libstdc++-v3/include/std/functional')
| -rw-r--r-- | libstdc++-v3/include/std/functional | 49 |
1 files changed, 31 insertions, 18 deletions
diff --git a/libstdc++-v3/include/std/functional b/libstdc++-v3/include/std/functional index f1dc839..19caa96 100644 --- a/libstdc++-v3/include/std/functional +++ b/libstdc++-v3/include/std/functional @@ -184,6 +184,33 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION : _Weak_result_type_impl<typename remove_cv<_Functor>::type> { }; + template<typename _Tp, typename _Up = typename decay<_Tp>::type> + struct _Unwrap + { + using type = _Tp&&; + + // Equivalent to std::forward<_Tp> + static constexpr _Tp&& + _S_fwd(_Tp& __t) noexcept { return static_cast<_Tp&&>(__t); } + }; + + template<typename _Tp, typename _Up> + struct _Unwrap<_Tp, reference_wrapper<_Up>> + { + using type = _Up&; + + // Get an lvalue-reference from a reference_wrapper. + static _Up& + _S_fwd(const _Tp& __t) noexcept { __t.get(); } + }; + + // Used by __invoke_impl instead of std::forward<_Tp> so that a + // reference_wrapper is converted to an lvalue-reference. + template<typename _Tp> + typename _Unwrap<_Tp>::type + __invfwd(typename remove_reference<_Tp>::type& __t) noexcept + { return _Unwrap<_Tp>::_S_fwd(__t); } + template<typename _Res, typename _Fn, typename... _Args> inline _Res __invoke_impl(__invoke_other, _Fn&& __f, _Args&&... __args) @@ -194,15 +221,8 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION inline _Res __invoke_impl(__invoke_memfun_ref, _MemFun&& __f, _Tp&& __t, _Args&&... __args) - noexcept(noexcept((forward<_Tp>(__t).*__f)(forward<_Args>(__args)...))) - { return (forward<_Tp>(__t).*__f)(forward<_Args>(__args)...); } - - template<typename _Res, typename _MemFun, typename _Tp, typename... _Args> - inline _Res - __invoke_impl(__invoke_memfun_ref, _MemFun&& __f, - reference_wrapper<_Tp> __t, _Args&&... __args) - noexcept(noexcept((__t.get().*__f)(forward<_Args>(__args)...))) - { return (__t.get().*__f)(forward<_Args>(__args)...); } + noexcept(noexcept((__invfwd<_Tp>(__t).*__f)(forward<_Args>(__args)...))) + { return (__invfwd<_Tp>(__t).*__f)(forward<_Args>(__args)...); } template<typename _Res, typename _MemFun, typename _Tp, typename... _Args> inline _Res @@ -214,15 +234,8 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION template<typename _Res, typename _MemFun, typename _Tp, typename... _Args> inline _Res __invoke_impl(__invoke_memobj_ref, _MemFun&& __f, _Tp&& __t) - noexcept(noexcept(forward<_Tp>(__t).*__f)) - { return forward<_Tp>(__t).*__f; } - - template<typename _Res, typename _MemFun, typename _Tp, typename... _Args> - inline _Res - __invoke_impl(__invoke_memobj_ref, _MemFun&& __f, - reference_wrapper<_Tp> __t) - noexcept(noexcept(__t.get().*__f)) - { return __t.get().*__f; } + noexcept(noexcept(__invfwd<_Tp>(__t).*__f)) + { return __invfwd<_Tp>(__t).*__f; } template<typename _Res, typename _MemFun, typename _Tp, typename... _Args> inline _Res |