fd954fcec7
These implementations have been copied from Chromium and adapted to build and run in WebRTC's environment. Bug: webrtc:12689 Change-Id: Id8ff5d86b00827102a6be9d613fad7864130d013 Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/224661 Commit-Queue: Victor Boivie <boivie@webrtc.org> Reviewed-by: Mirko Bonadei <mbonadei@webrtc.org> Cr-Commit-Position: refs/heads/master@{#34425}
65 lines
1.8 KiB
C++
65 lines
1.8 KiB
C++
/*
|
|
* Copyright (c) 2021 The WebRTC project authors. All Rights Reserved.
|
|
*
|
|
* Use of this source code is governed by a BSD-style license
|
|
* that can be found in the LICENSE file in the root of the source
|
|
* tree. An additional intellectual property rights grant can be found
|
|
* in the file PATENTS. All contributing project authors may
|
|
* be found in the AUTHORS file in the root of the source tree.
|
|
*/
|
|
|
|
// This implementation is borrowed from Chromium.
|
|
|
|
#ifndef RTC_BASE_CONTAINERS_NOT_FN_H_
|
|
#define RTC_BASE_CONTAINERS_NOT_FN_H_
|
|
|
|
#include <type_traits>
|
|
#include <utility>
|
|
|
|
#include "rtc_base/containers/invoke.h"
|
|
|
|
namespace webrtc {
|
|
|
|
namespace not_fn_internal {
|
|
|
|
template <typename F>
|
|
struct NotFnImpl {
|
|
F f;
|
|
|
|
template <typename... Args>
|
|
constexpr decltype(auto) operator()(Args&&... args) & noexcept {
|
|
return !webrtc::invoke(f, std::forward<Args>(args)...);
|
|
}
|
|
|
|
template <typename... Args>
|
|
constexpr decltype(auto) operator()(Args&&... args) const& noexcept {
|
|
return !webrtc::invoke(f, std::forward<Args>(args)...);
|
|
}
|
|
|
|
template <typename... Args>
|
|
constexpr decltype(auto) operator()(Args&&... args) && noexcept {
|
|
return !webrtc::invoke(std::move(f), std::forward<Args>(args)...);
|
|
}
|
|
|
|
template <typename... Args>
|
|
constexpr decltype(auto) operator()(Args&&... args) const&& noexcept {
|
|
return !webrtc::invoke(std::move(f), std::forward<Args>(args)...);
|
|
}
|
|
};
|
|
|
|
} // namespace not_fn_internal
|
|
|
|
// Implementation of C++17's std::not_fn.
|
|
//
|
|
// Reference:
|
|
// - https://en.cppreference.com/w/cpp/utility/functional/not_fn
|
|
// - https://wg21.link/func.not.fn
|
|
template <typename F>
|
|
constexpr not_fn_internal::NotFnImpl<std::decay_t<F>> not_fn(F&& f) {
|
|
return {std::forward<F>(f)};
|
|
}
|
|
|
|
} // namespace webrtc
|
|
|
|
#endif // RTC_BASE_CONTAINERS_NOT_FN_H_
|