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| author | Jonathan Wakely <jwakely@redhat.com> | 2018-06-15 01:19:07 +0100 |
|---|---|---|
| committer | Jonathan Wakely <redi@gcc.gnu.org> | 2018-06-15 01:19:07 +0100 |
| commit | cb4f9a8c05fd36d78faaddb4635b4bfb80bba457 (patch) | |
| tree | 5d50c2c7af59c9318d5d85923118f76535e23f50 /libstdc++-v3/include/std/future | |
| parent | 024e96b90bd2bc4f88aaeb62295d6c919a5cd804 (diff) | |
| download | gcc-cb4f9a8c05fd36d78faaddb4635b4bfb80bba457.zip gcc-cb4f9a8c05fd36d78faaddb4635b4bfb80bba457.tar.gz gcc-cb4f9a8c05fd36d78faaddb4635b4bfb80bba457.tar.bz2 | |
LWG 3039 Unnecessary decay in thread and packaged_task
* include/std/future (__constrain_pkgdtask): Replace with ...
(packaged_task::__not_same): New alias template, using
__remove_cvref_t instead of decay.
* include/std/thread (thread::__not_same): Add comment.
From-SVN: r261618
Diffstat (limited to 'libstdc++-v3/include/std/future')
| -rw-r--r-- | libstdc++-v3/include/std/future | 23 |
1 files changed, 9 insertions, 14 deletions
diff --git a/libstdc++-v3/include/std/future b/libstdc++-v3/include/std/future index c17a253..937c05e 100644 --- a/libstdc++-v3/include/std/future +++ b/libstdc++-v3/include/std/future @@ -1462,15 +1462,6 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION static_cast<_Alloc&>(_M_impl)); } - template<typename _Task, typename _Fn, bool - = is_same<_Task, typename decay<_Fn>::type>::value> - struct __constrain_pkgdtask - { typedef void __type; }; - - template<typename _Task, typename _Fn> - struct __constrain_pkgdtask<_Task, _Fn, true> - { }; - /// packaged_task template<typename _Res, typename... _ArgTypes> class packaged_task<_Res(_ArgTypes...)> @@ -1478,6 +1469,12 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION typedef __future_base::_Task_state_base<_Res(_ArgTypes...)> _State_type; shared_ptr<_State_type> _M_state; + // _GLIBCXX_RESOLVE_LIB_DEFECTS + // 3039. Unnecessary decay in thread and packaged_task + template<typename _Fn, typename _Fn2 = __remove_cvref_t<_Fn>> + using __not_same + = typename enable_if<!is_same<packaged_task, _Fn2>::value>::type; + public: // Construction and destruction packaged_task() noexcept { } @@ -1488,8 +1485,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION packaged_task(allocator_arg_t, const _Allocator& __a) noexcept { } - template<typename _Fn, typename = typename - __constrain_pkgdtask<packaged_task, _Fn>::__type> + template<typename _Fn, typename = __not_same<_Fn>> explicit packaged_task(_Fn&& __fn) : packaged_task(allocator_arg, std::allocator<int>(), @@ -1499,11 +1495,10 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION // _GLIBCXX_RESOLVE_LIB_DEFECTS // 2097. packaged_task constructors should be constrained // 2407. [this constructor should not be] explicit - template<typename _Fn, typename _Alloc, typename = typename - __constrain_pkgdtask<packaged_task, _Fn>::__type> + template<typename _Fn, typename _Alloc, typename = __not_same<_Fn>> packaged_task(allocator_arg_t, const _Alloc& __a, _Fn&& __fn) : _M_state(__create_task_state<_Res(_ArgTypes...)>( - std::forward<_Fn>(__fn), __a)) + std::forward<_Fn>(__fn), __a)) { } ~packaged_task() |