xpcom/string/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 "nsCharTraits.h"  // for |nsCharSourceTraits|, |nsCharSinkTraits|
  11
  12 template <class T>
  13 inline T
  14 NS_ROUNDUP(const T& aA, const T& aB)
  15 {
  16   return ((aA + (aB - 1)) / aB) * aB;
  17 }
  18
  19 // We use these instead of std::min/max because we can't include the algorithm
  20 // header in all of XPCOM because the stl wrappers will error out when included
  21 // in parts of XPCOM. These functions should never be used outside of XPCOM.
  22 template <class T>
  23 inline const T&
  24 XPCOM_MIN(const T& aA, const T& aB)
  25 {
  26   return aB < aA ? aB : aA;
  27 }
  28
  29 // Must return b when a == b in case a is -0
  30 template <class T>
  31 inline const T&
  32 XPCOM_MAX(const T& aA, const T& aB)
  33 {
  34   return aA > aB ? aA : aB;
  35 }
  36
  37 namespace mozilla {
  38
  39 template <class T>
  40 inline const T&
  41 clamped(const T& aA, const T& aMin, const T& aMax)
  42 {
  43   NS_ABORT_IF_FALSE(aMax >= aMin,
  44                     "clamped(): aMax must be greater than or equal to aMin");
  45   return XPCOM_MIN(XPCOM_MAX(aA, aMin), aMax);
  46 }
  47
  48 }
  49
  50 template <class InputIterator, class T>
  51 inline uint32_t
  52 NS_COUNT(InputIterator& aFirst, const InputIterator& aLast, const T& aValue)
  53 {
  54   uint32_t result = 0;
  55   for (; aFirst != aLast; ++aFirst)
  56     if (*aFirst == aValue) {
  57       ++result;
  58     }
  59   return result;
  60 }
  61
  62 template <class InputIterator, class OutputIterator>
  63 inline OutputIterator&
  64 copy_string(const InputIterator& aFirst, const InputIterator& aLast,
  65             OutputIterator& aResult)
  66 {
  67   typedef nsCharSourceTraits<InputIterator> source_traits;
  68   typedef nsCharSinkTraits<OutputIterator>  sink_traits;
  69
  70   sink_traits::write(aResult, source_traits::read(aFirst),
  71                      source_traits::readable_distance(aFirst, aLast));
  72   return aResult;
  73 }
  74
  75 #endif // !defined(nsAlgorithm_h___)