71 lines
2.3 KiB
C
71 lines
2.3 KiB
C
|
/*
|
||
|
|
* Copyright 2014 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.
|
||
|
|
*/
|
||
|
|
|
||
|
|
// Borrowed from Chromium's src/base/numerics/safe_conversions.h.
|
||
|
|
|
||
|
|
#ifndef WEBRTC_BASE_SAFE_CONVERSIONS_H_
|
||
|
|
#define WEBRTC_BASE_SAFE_CONVERSIONS_H_
|
||
|
|
|
||
|
|
#include <limits>
|
||
|
|
|
||
|
|
#include "webrtc/base/checks.h"
|
||
|
|
#include "webrtc/base/safe_conversions_impl.h"
|
||
|
|
|
||
|
|
namespace rtc {
|
||
|
|
|
||
|
|
// Convenience function that returns true if the supplied value is in range
|
||
|
|
// for the destination type.
|
||
|
|
template <typename Dst, typename Src>
|
||
|
|
inline bool IsValueInRangeForNumericType(Src value) {
|
||
|
|
return internal::RangeCheck<Dst>(value) == internal::TYPE_VALID;
|
||
|
|
}
|
||
|
|
|
||
|
|
// checked_cast<> is analogous to static_cast<> for numeric types,
|
||
|
|
// except that it CHECKs that the specified numeric conversion will not
|
||
|
|
// overflow or underflow. NaN source will always trigger a CHECK.
|
||
|
|
template <typename Dst, typename Src>
|
||
|
|
inline Dst checked_cast(Src value) {
|
||
|
|
RTC_CHECK(IsValueInRangeForNumericType<Dst>(value));
|
||
|
|
return static_cast<Dst>(value);
|
||
|
|
}
|
||
|
|
|
||
|
|
// saturated_cast<> is analogous to static_cast<> for numeric types, except
|
||
|
|
// that the specified numeric conversion will saturate rather than overflow or
|
||
|
|
// underflow. NaN assignment to an integral will trigger a RTC_CHECK condition.
|
||
|
|
template <typename Dst, typename Src>
|
||
|
|
inline Dst saturated_cast(Src value) {
|
||
|
|
// Optimization for floating point values, which already saturate.
|
||
|
|
if (std::numeric_limits<Dst>::is_iec559)
|
||
|
|
return static_cast<Dst>(value);
|
||
|
|
|
||
|
|
switch (internal::RangeCheck<Dst>(value)) {
|
||
|
|
case internal::TYPE_VALID:
|
||
|
|
return static_cast<Dst>(value);
|
||
|
|
|
||
|
|
case internal::TYPE_UNDERFLOW:
|
||
|
|
return std::numeric_limits<Dst>::min();
|
||
|
|
|
||
|
|
case internal::TYPE_OVERFLOW:
|
||
|
|
return std::numeric_limits<Dst>::max();
|
||
|
|
|
||
|
|
// Should fail only on attempting to assign NaN to a saturated integer.
|
||
|
|
case internal::TYPE_INVALID:
|
||
|
|
FATAL();
|
||
|
|
return std::numeric_limits<Dst>::max();
|
||
|
|
}
|
||
|
|
|
||
|
|
FATAL();
|
||
|
|
return static_cast<Dst>(value);
|
||
|
|
}
|
||
|
|
|
||
|
|
} // namespace rtc
|
||
|
|
|
||
|
|
#endif // WEBRTC_BASE_SAFE_CONVERSIONS_H_
|