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| author | Jonathan Wakely <jwakely@redhat.com> | 2019-10-24 15:39:57 +0100 |
|---|---|---|
| committer | Jonathan Wakely <redi@gcc.gnu.org> | 2019-10-24 15:39:57 +0100 |
| commit | 5ce55f3ff5d04834e436a72fb2be84b31aa89def (patch) | |
| tree | 7b16d64999ebbe045ddfea954e0e9e1131ec6672 | |
| parent | abebffc609506176f8ba3f64533e15ece49446c0 (diff) | |
| download | gcc-5ce55f3ff5d04834e436a72fb2be84b31aa89def.zip gcc-5ce55f3ff5d04834e436a72fb2be84b31aa89def.tar.gz gcc-5ce55f3ff5d04834e436a72fb2be84b31aa89def.tar.bz2 | |
Simplify common case of use_future_t that uses std::allocator
There is no need to store and pass around the allocator object when it's
an instance of std::allocator. Define a partial specialization of
std::use_future_t and the corresponding completion token so that no
allocator is stored. Overload the completion handler constructor to not
expect an allocator to be stored.
* include/experimental/executor (__use_future_ct, use_future_t):
Define partial specializations for std::allocator.
(__use_future_ch): Overload constructor for completion tokens using
std::allocator.
From-SVN: r277404
| -rw-r--r-- | libstdc++-v3/ChangeLog | 5 | ||||
| -rw-r--r-- | libstdc++-v3/include/experimental/executor | 45 |
2 files changed, 48 insertions, 2 deletions
diff --git a/libstdc++-v3/ChangeLog b/libstdc++-v3/ChangeLog index d65c845..13e834b 100644 --- a/libstdc++-v3/ChangeLog +++ b/libstdc++-v3/ChangeLog @@ -1,5 +1,10 @@ 2019-10-24 Jonathan Wakely <jwakely@redhat.com> + * include/experimental/executor (__use_future_ct, use_future_t): + Define partial specializations for std::allocator. + (__use_future_ch): Overload constructor for completion tokens using + std::allocator. + PR libstdc++/88338 Implement P0898R3, C++20 concepts library * doc/xml/manual/status_cxx2020.xml: Update status. * doc/html/*: Regenerate. diff --git a/libstdc++-v3/include/experimental/executor b/libstdc++-v3/include/experimental/executor index ef141e9..ed18730 100644 --- a/libstdc++-v3/include/experimental/executor +++ b/libstdc++-v3/include/experimental/executor @@ -1501,12 +1501,18 @@ inline namespace v1 std::tuple<_Func, _Alloc> _M_t; }; + template<typename _Func, typename _Tp> + struct __use_future_ct<_Func, std::allocator<_Tp>> + { + _Func _M_f; + }; + template<typename _ProtoAllocator = allocator<void>> class use_future_t { public: // use_future_t types: - typedef _ProtoAllocator allocator_type; + using allocator_type = _ProtoAllocator; // use_future_t members: constexpr use_future_t() noexcept : _M_alloc() { } @@ -1514,7 +1520,7 @@ inline namespace v1 explicit use_future_t(const _ProtoAllocator& __a) noexcept : _M_alloc(__a) { } - template<class _OtherAllocator> + template<typename _OtherAllocator> use_future_t<_OtherAllocator> rebind(const _OtherAllocator& __a) const noexcept { return use_future_t<_OtherAllocator>(__a); } @@ -1533,6 +1539,35 @@ inline namespace v1 _ProtoAllocator _M_alloc; }; + template<typename _Tp> + class use_future_t<std::allocator<_Tp>> + { + public: + // use_future_t types: + using allocator_type = std::allocator<_Tp>; + + // use_future_t members: + constexpr use_future_t() noexcept = default; + + explicit + use_future_t(const allocator_type& __a) noexcept { } + + template<class _Up> + use_future_t<std::allocator<_Up>> + rebind(const std::allocator<_Up>& __a) const noexcept + { return use_future_t<std::allocator<_Up>>(__a); } + + allocator_type get_allocator() const noexcept { return {}; } + + template<typename _Func> + auto + operator()(_Func&& __f) const + { + using _Token = __use_future_ct<decay_t<_Func>, allocator_type>; + return _Token{std::forward<_Func>(__f)}; + } + }; + constexpr use_future_t<> use_future = use_future_t<>(); template<typename _Func, typename _Alloc, typename _Res, typename... _Args> @@ -1552,6 +1587,12 @@ inline namespace v1 _M_promise{ std::get<1>(__token._M_t) } { } + template<typename _Tp> + explicit + __use_future_ch(__use_future_ct<_Func, std::allocator<_Tp>>&& __token) + : _M_f{ std::move(__token._M_f) } + { } + void operator()(_Args&&... __args) { |