libstdc++-v3/include/parallel/checkers.h

   1 // -*- C++ -*-
   2
   3 // Copyright (C) 2007-2017 Free Software Foundation, Inc.
   4 //
   5 // This file is part of the GNU ISO C++ Library.  This library is free
   6 // software; you can redistribute it and/or modify it under the terms
   7 // of the GNU General Public License as published by the Free Software
   8 // Foundation; either version 3, or (at your option) any later
   9 // version.
  10
  11 // This library is distributed in the hope that it will be useful, but
  12 // WITHOUT ANY WARRANTY; without even the implied warranty of
  13 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14 // General Public License for more details.
  15
  16 // Under Section 7 of GPL version 3, you are granted additional
  17 // permissions described in the GCC Runtime Library Exception, version
  18 // 3.1, as published by the Free Software Foundation.
  19
  20 // You should have received a copy of the GNU General Public License and
  21 // a copy of the GCC Runtime Library Exception along with this program;
  22 // see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
  23 // <http://www.gnu.org/licenses/>.
  24
  25 /** @file parallel/checkers.h
  26  *  @brief Routines for checking the correctness of algorithm results.
  27  *  This file is a GNU parallel extension to the Standard C++ Library.
  28  */
  29
  30 // Written by Johannes Singler.
  31
  32 #ifndef _GLIBCXX_PARALLEL_CHECKERS_H
  33 #define _GLIBCXX_PARALLEL_CHECKERS_H 1
  34
  35 #include <cstdio>
  36 #include <bits/stl_algobase.h>
  37 #include <bits/stl_function.h>
  38
  39 namespace __gnu_parallel
  40 {
  41   /**
  42    * @brief Check whether @c [__begin, @c __end) is sorted according
  43    * to @c __comp.
  44    * @param __begin Begin iterator of sequence.
  45    * @param __end End iterator of sequence.
  46    * @param __comp Comparator.
  47    * @return @c true if sorted, @c false otherwise.
  48    */
  49   template<typename _IIter, typename _Compare>
  50     bool
  51     __is_sorted(_IIter __begin, _IIter __end, _Compare __comp)
  52     {
  53       if (__begin == __end)
  54         return true;
  55
  56       _IIter __current(__begin), __recent(__begin);
  57
  58       unsigned long long __position = 1;
  59       for (__current++; __current != __end; __current++)
  60         {
  61           if (__comp(*__current, *__recent))
  62             {
  63               return false;
  64             }
  65           __recent = __current;
  66           __position++;
  67         }
  68
  69       return true;
  70     }
  71 }
  72
  73 #endif /* _GLIBCXX_PARALLEL_CHECKERS_H */