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/*
* Copyright 2019 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.
*/
#ifndef RTC_BASE_NUMERICS_DIVIDE_ROUND_H_
#define RTC_BASE_NUMERICS_DIVIDE_ROUND_H_
#include <type_traits>
#include "rtc_base/checks.h"
#include "rtc_base/numerics/safe_compare.h"
namespace webrtc {
template <typename Dividend, typename Divisor>
inline auto constexpr DivideRoundUp(Dividend dividend, Divisor divisor) {
static_assert(std::is_integral<Dividend>(), "");
static_assert(std::is_integral<Divisor>(), "");
RTC_DCHECK_GE(dividend, 0);
RTC_DCHECK_GT(divisor, 0);
auto quotient = dividend / divisor;
auto remainder = dividend % divisor;
return quotient + (remainder > 0 ? 1 : 0);
}
template <typename Dividend, typename Divisor>
inline auto constexpr DivideRoundToNearest(Dividend dividend, Divisor divisor) {
static_assert(std::is_integral<Dividend>(), "");
static_assert(std::is_integral<Divisor>(), "");
RTC_DCHECK_GT(divisor, 0);
if (dividend < Dividend{0}) {
auto half_of_divisor = divisor / 2;
auto quotient = dividend / divisor;
auto remainder = dividend % divisor;
if (rtc::SafeGt(-remainder, half_of_divisor)) {
--quotient;
}
return quotient;
}
auto half_of_divisor = (divisor - 1) / 2;
auto quotient = dividend / divisor;
auto remainder = dividend % divisor;
if (rtc::SafeGt(remainder, half_of_divisor)) {
++quotient;
}
return quotient;
}
} // namespace webrtc
#endif // RTC_BASE_NUMERICS_DIVIDE_ROUND_H_
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