diff options
Diffstat (limited to 'chromium/third_party/libjingle/source/talk/base/safe_conversions.h')
-rw-r--r-- | chromium/third_party/libjingle/source/talk/base/safe_conversions.h | 96 |
1 files changed, 96 insertions, 0 deletions
diff --git a/chromium/third_party/libjingle/source/talk/base/safe_conversions.h b/chromium/third_party/libjingle/source/talk/base/safe_conversions.h new file mode 100644 index 00000000000..d246d4ffce1 --- /dev/null +++ b/chromium/third_party/libjingle/source/talk/base/safe_conversions.h @@ -0,0 +1,96 @@ +/* + * libjingle + * Copyright 2014, Google Inc. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions are met: + * + * 1. Redistributions of source code must retain the above copyright notice, + * this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright notice, + * this list of conditions and the following disclaimer in the documentation + * and/or other materials provided with the distribution. + * 3. The name of the author may not be used to endorse or promote products + * derived from this software without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED + * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF + * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO + * EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, + * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, + * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; + * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, + * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR + * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF + * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + */ + +// Borrowed from Chromium's src/base/numerics/safe_conversions.h. + +#ifndef TALK_BASE_SAFE_CONVERSIONS_H_ +#define TALK_BASE_SAFE_CONVERSIONS_H_ + +#include <limits> + +#include "talk/base/common.h" +#include "talk/base/logging.h" +#include "talk/base/safe_conversions_impl.h" + +namespace talk_base { + +inline void Check(bool condition) { + if (!condition) { + LOG(LS_ERROR) << "CHECK failed."; + Break(); + // The program should have crashed at this point. + } +} + +// 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) { + 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 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: + Check(false); + return std::numeric_limits<Dst>::max(); + } + + Check(false); // NOTREACHED(); + return static_cast<Dst>(value); +} + +} // namespace talk_base + +#endif // TALK_BASE_SAFE_CONVERSIONS_H_ |