llvm-project/libcxx/include/__functional/not_fn.h

55 lines
1.6 KiB
C++

// -*- C++ -*-
//===----------------------------------------------------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
#ifndef _LIBCPP___FUNCTIONAL_NOT_FN_H
#define _LIBCPP___FUNCTIONAL_NOT_FN_H
#include <__config>
#include <__functional/invoke.h>
#include <__functional/perfect_forward.h>
#include <__utility/forward.h>
#include <type_traits>
#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
# pragma GCC system_header
#endif
_LIBCPP_BEGIN_NAMESPACE_STD
#if _LIBCPP_STD_VER > 14
struct __not_fn_op {
template <class... _Args>
_LIBCPP_HIDE_FROM_ABI
_LIBCPP_CONSTEXPR_AFTER_CXX17 auto operator()(_Args&&... __args) const
noexcept(noexcept(!_VSTD::invoke(_VSTD::forward<_Args>(__args)...)))
-> decltype( !_VSTD::invoke(_VSTD::forward<_Args>(__args)...))
{ return !_VSTD::invoke(_VSTD::forward<_Args>(__args)...); }
};
template <class _Fn>
struct __not_fn_t : __perfect_forward<__not_fn_op, _Fn> {
using __perfect_forward<__not_fn_op, _Fn>::__perfect_forward;
};
template <class _Fn, class = enable_if_t<
is_constructible_v<decay_t<_Fn>, _Fn> &&
is_move_constructible_v<decay_t<_Fn>>
>>
_LIBCPP_HIDE_FROM_ABI
_LIBCPP_CONSTEXPR_AFTER_CXX17 auto not_fn(_Fn&& __f) {
return __not_fn_t<decay_t<_Fn>>(_VSTD::forward<_Fn>(__f));
}
#endif // _LIBCPP_STD_VER > 14
_LIBCPP_END_NAMESPACE_STD
#endif // _LIBCPP___FUNCTIONAL_NOT_FN_H