xref: /freebsd-src/contrib/llvm-project/libcxx/include/__functional/bind_front.h (revision 0fca6ea1d4eea4c934cfff25ac9ee8ad6fe95583)
1fe6060f1SDimitry Andric // -*- C++ -*-
2fe6060f1SDimitry Andric //===----------------------------------------------------------------------===//
3fe6060f1SDimitry Andric //
4fe6060f1SDimitry Andric // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
5fe6060f1SDimitry Andric // See https://llvm.org/LICENSE.txt for license information.
6fe6060f1SDimitry Andric // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
7fe6060f1SDimitry Andric //
8fe6060f1SDimitry Andric //===----------------------------------------------------------------------===//
9fe6060f1SDimitry Andric 
10fe6060f1SDimitry Andric #ifndef _LIBCPP___FUNCTIONAL_BIND_FRONT_H
11fe6060f1SDimitry Andric #define _LIBCPP___FUNCTIONAL_BIND_FRONT_H
12fe6060f1SDimitry Andric 
13fe6060f1SDimitry Andric #include <__config>
14fe6060f1SDimitry Andric #include <__functional/invoke.h>
1504eeddc0SDimitry Andric #include <__functional/perfect_forward.h>
1606c3fb27SDimitry Andric #include <__type_traits/conjunction.h>
1706c3fb27SDimitry Andric #include <__type_traits/decay.h>
1806c3fb27SDimitry Andric #include <__type_traits/enable_if.h>
1906c3fb27SDimitry Andric #include <__type_traits/is_constructible.h>
2081ad6265SDimitry Andric #include <__utility/forward.h>
21fe6060f1SDimitry Andric 
22fe6060f1SDimitry Andric #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
23fe6060f1SDimitry Andric #  pragma GCC system_header
24fe6060f1SDimitry Andric #endif
25fe6060f1SDimitry Andric 
26fe6060f1SDimitry Andric _LIBCPP_BEGIN_NAMESPACE_STD
27fe6060f1SDimitry Andric 
2806c3fb27SDimitry Andric #if _LIBCPP_STD_VER >= 20
29fe6060f1SDimitry Andric 
30349cc55cSDimitry Andric struct __bind_front_op {
31fe6060f1SDimitry Andric   template <class... _Args>
32*0fca6ea1SDimitry Andric   _LIBCPP_HIDE_FROM_ABI constexpr auto operator()(_Args&&... __args) const noexcept(
33*0fca6ea1SDimitry Andric       noexcept(std::invoke(std::forward<_Args>(__args)...))) -> decltype(std::invoke(std::forward<_Args>(__args)...)) {
34cb14a3feSDimitry Andric     return std::invoke(std::forward<_Args>(__args)...);
35cb14a3feSDimitry Andric   }
36fe6060f1SDimitry Andric };
37fe6060f1SDimitry Andric 
38349cc55cSDimitry Andric template <class _Fn, class... _BoundArgs>
39349cc55cSDimitry Andric struct __bind_front_t : __perfect_forward<__bind_front_op, _Fn, _BoundArgs...> {
40349cc55cSDimitry Andric   using __perfect_forward<__bind_front_op, _Fn, _BoundArgs...>::__perfect_forward;
41349cc55cSDimitry Andric };
42349cc55cSDimitry Andric 
435f757f3fSDimitry Andric template <class _Fn, class... _Args>
445f757f3fSDimitry Andric   requires is_constructible_v<decay_t<_Fn>, _Fn> && is_move_constructible_v<decay_t<_Fn>> &&
455f757f3fSDimitry Andric            (is_constructible_v<decay_t<_Args>, _Args> && ...) && (is_move_constructible_v<decay_t<_Args>> && ...)
46cb14a3feSDimitry Andric _LIBCPP_HIDE_FROM_ABI constexpr auto bind_front(_Fn&& __f, _Args&&... __args) {
475f757f3fSDimitry Andric   return __bind_front_t<decay_t<_Fn>, decay_t<_Args>...>(std::forward<_Fn>(__f), std::forward<_Args>(__args)...);
48fe6060f1SDimitry Andric }
49fe6060f1SDimitry Andric 
5006c3fb27SDimitry Andric #endif // _LIBCPP_STD_VER >= 20
51fe6060f1SDimitry Andric 
52fe6060f1SDimitry Andric _LIBCPP_END_NAMESPACE_STD
53fe6060f1SDimitry Andric 
54fe6060f1SDimitry Andric #endif // _LIBCPP___FUNCTIONAL_BIND_FRONT_H
55