libstdc++-v3/testsuite/25_algorithms/binary_search/2.cc

   1 // Copyright (C) 2001-2021 Free Software Foundation, Inc.
   2 //
   3 // This file is part of the GNU ISO C++ Library.  This library is free
   4 // software; you can redistribute it and/or modify it under the
   5 // terms of the GNU General Public License as published by the
   6 // Free Software Foundation; either version 3, or (at your option)
   7 // any later version.
   8
   9 // This library is distributed in the hope that it will be useful,
  10 // but WITHOUT ANY WARRANTY; without even the implied warranty of
  11 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12 // GNU General Public License for more details.
  13
  14 // You should have received a copy of the GNU General Public License along
  15 // with this library; see the file COPYING3.  If not see
  16 // <http://www.gnu.org/licenses/>.
  17
  18 // 25.3.3 [lib.alg.binary.search] Binary search algorithms.
  19
  20 #include <algorithm>
  21 #include <testsuite_hooks.h>
  22
  23 const int A[] = {1, 2, 3, 3, 3, 5, 8};
  24 const int C[] = {8, 5, 3, 3, 3, 2, 1};
  25 const int N = sizeof(A) / sizeof(int);
  26
  27 // A comparison, equalivalent to std::greater<int> without the
  28 // dependency on <functional>.
  29 struct gt
  30 {
  31     bool
  32     operator()(const int& x, const int& y) const
  33     { return x > y; }
  34 };
  35
  36 // 25.3.3.4 binary_search, with and without comparison predicate
  37 void
  38 test04()
  39 {
  40     using std::binary_search;
  41
  42     const int first = A[0];
  43     const int last = A[N - 1];
  44
  45     VERIFY(binary_search(A, A + N, 5));
  46     VERIFY(binary_search(A, A + N, first));
  47     VERIFY(binary_search(A, A + N, last));
  48     VERIFY(!binary_search(A, A + N, 4));
  49
  50     VERIFY(binary_search(C, C + N, 5, gt()));
  51     VERIFY(binary_search(C, C + N, first, gt()));
  52     VERIFY(binary_search(C, C + N, last, gt()));
  53     VERIFY(!binary_search(C, C + N, 4, gt()));
  54 }
  55
  56 int
  57 main()
  58 {
  59   test04();
  60   return 0;
  61 }