xpcom/base/nsAlgorithm.h

   1 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
   2 /* vim: set ts=8 sts=2 et sw=2 tw=80: */
   3 /* This Source Code Form is subject to the terms of the Mozilla Public
   4  * License, v. 2.0. If a copy of the MPL was not distributed with this
   5  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   6
   7 #ifndef nsAlgorithm_h___
   8 #define nsAlgorithm_h___
   9
  10 #include <cstdint>
  11 #include "mozilla/Assertions.h"
  12
  13 template <class T>
  14 inline T NS_ROUNDUP(const T& aA, const T& aB) {
  15   return ((aA + (aB - 1)) / aB) * aB;
  16 }
  17
  18 // We use these instead of std::min/max because we can't include the algorithm
  19 // header in all of XPCOM because the stl wrappers will error out when included
  20 // in parts of XPCOM. These functions should never be used outside of XPCOM.
  21 template <class T>
  22 inline const T& XPCOM_MIN(const T& aA, const T& aB) {
  23   return aB < aA ? aB : aA;
  24 }
  25
  26 // Must return b when a == b in case a is -0
  27 template <class T>
  28 inline const T& XPCOM_MAX(const T& aA, const T& aB) {
  29   return aA > aB ? aA : aB;
  30 }
  31
  32 namespace mozilla {
  33
  34 template <class T>
  35 inline const T& clamped(const T& aA, const T& aMin, const T& aMax) {
  36   MOZ_ASSERT(aMax >= aMin,
  37              "clamped(): aMax must be greater than or equal to aMin");
  38   return XPCOM_MIN(XPCOM_MAX(aA, aMin), aMax);
  39 }
  40
  41 }  // namespace mozilla
  42
  43 template <class InputIterator, class T>
  44 inline uint32_t NS_COUNT(InputIterator& aFirst, const InputIterator& aLast,
  45                          const T& aValue) {
  46   uint32_t result = 0;
  47   for (; aFirst != aLast; ++aFirst)
  48     if (*aFirst == aValue) {
  49       ++result;
  50     }
  51   return result;
  52 }
  53
  54 #endif  // !defined(nsAlgorithm_h___)