net/dcsctp/common/math.h

/*
 *  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.
 */
#ifndef NET_DCSCTP_COMMON_MATH_H_
#define NET_DCSCTP_COMMON_MATH_H_

namespace dcsctp {

// Rounds up `val` to the nearest value that is divisible by four. Frequently
// used to e.g. pad chunks or parameters to an even 32-bit offset.
template <typename IntType>
IntType RoundUpTo4(IntType val) {
  return (val + 3) & ~3;
}

// Similarly, rounds down `val` to the nearest value that is divisible by four.
template <typename IntType>
IntType RoundDownTo4(IntType val) {
  return val & ~3;
}

// Returns true if `val` is divisible by four.
template <typename IntType>
bool IsDivisibleBy4(IntType val) {
  return (val & 3) == 0;
}

}  // namespace dcsctp

#endif  // NET_DCSCTP_COMMON_MATH_H_