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// Copyright 2021 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#ifndef BASE_CXX17_BACKPORTS_H_
#define BASE_CXX17_BACKPORTS_H_
#include <functional>
#include "base/check.h"
namespace base {
// C++14 implementation of C++17's std::clamp():
// https://en.cppreference.com/w/cpp/algorithm/clamp
// Please note that the C++ spec makes it undefined behavior to call std::clamp
// with a value of `lo` that compares greater than the value of `hi`. This
// implementation uses a CHECK to enforce this as a hard restriction.
template <typename T, typename Compare>
constexpr const T& clamp(const T& v, const T& lo, const T& hi, Compare comp) {
CHECK(!comp(hi, lo));
return comp(v, lo) ? lo : comp(hi, v) ? hi : v;
}
template <typename T>
constexpr const T& clamp(const T& v, const T& lo, const T& hi) {
return base::clamp(v, lo, hi, std::less<T>{});
}
} // namespace base
#endif // BASE_CXX17_BACKPORTS_H_
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