libs/algorithm/test/equal_test.cpp

   1 /*
   2    Copyright (c) Marshall Clow 2013.
   3
   4    Distributed under the Boost Software License, Version 1.0. (See accompanying
   5    file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
   6
   7     For more information, see http://www.boost.org
   8 */
   9
  10 #include <boost/config.hpp>
  11 #include <boost/algorithm/cxx14/equal.hpp>
  12
  13 #include "iterator_test.hpp"
  14
  15 #define BOOST_TEST_MAIN
  16 #include <boost/test/unit_test.hpp>
  17
  18 template <typename T>
  19 bool eq ( const T& a, const T& b ) { return a == b; }
  20
  21 template <typename T>
  22 bool never_eq ( const T&, const T& ) { return false; }
  23
  24 int comparison_count = 0;
  25 template <typename T>
  26 bool counting_equals ( const T &a, const T &b ) {
  27     ++comparison_count;
  28     return a == b;
  29     }
  30
  31 namespace ba = boost::algorithm;
  32
  33 void test_equal ()
  34 {
  35 //  Note: The literal values here are tested against directly, careful if you change them:
  36     int num[] = { 1, 1, 2, 3, 5 };
  37     const int sz = sizeof (num)/sizeof(num[0]);
  38
  39
  40 //  Empty sequences are equal to each other, but not to non-empty sequences
  41     BOOST_CHECK ( ba::equal ( input_iterator<int *>(num),     input_iterator<int *>(num),
  42                               input_iterator<int *>(num),     input_iterator<int *>(num)));
  43     BOOST_CHECK ( ba::equal ( input_iterator<int *>(num),     input_iterator<int *>(num),
  44                               input_iterator<int *>(num),     input_iterator<int *>(num),
  45                               never_eq<int> ));
  46     BOOST_CHECK ( ba::equal ( random_access_iterator<int *>(num),     random_access_iterator<int *>(num),
  47                               random_access_iterator<int *>(num),     random_access_iterator<int *>(num),
  48                               never_eq<int> ));
  49
  50     BOOST_CHECK (!ba::equal ( input_iterator<int *>(num),     input_iterator<int *>(num),
  51                               input_iterator<int *>(num),     input_iterator<int *>(num + 1)));
  52     BOOST_CHECK (!ba::equal ( input_iterator<int *>(num + 1), input_iterator<int *>(num + 2),
  53                               input_iterator<int *>(num),     input_iterator<int *>(num)));
  54     BOOST_CHECK (!ba::equal ( random_access_iterator<int *>(num + 1), random_access_iterator<int *>(num + 2),
  55                               random_access_iterator<int *>(num),     random_access_iterator<int *>(num)));
  56
  57 //  Single element sequences are equal if they contain the same value
  58     BOOST_CHECK ( ba::equal ( input_iterator<int *>(num),     input_iterator<int *>(num + 1),
  59                               input_iterator<int *>(num),     input_iterator<int *>(num + 1)));
  60     BOOST_CHECK ( ba::equal ( input_iterator<int *>(num),     input_iterator<int *>(num + 1),
  61                               input_iterator<int *>(num),     input_iterator<int *>(num + 1),
  62                               eq<int> ));
  63     BOOST_CHECK ( ba::equal ( random_access_iterator<int *>(num),     random_access_iterator<int *>(num + 1),
  64                               random_access_iterator<int *>(num),     random_access_iterator<int *>(num + 1),
  65                               eq<int> ));
  66     BOOST_CHECK (!ba::equal ( input_iterator<int *>(num),     input_iterator<int *>(num + 1),
  67                               input_iterator<int *>(num),     input_iterator<int *>(num + 1),
  68                               never_eq<int> ));
  69     BOOST_CHECK (!ba::equal ( random_access_iterator<int *>(num),     random_access_iterator<int *>(num + 1),
  70                               random_access_iterator<int *>(num),     random_access_iterator<int *>(num + 1),
  71                               never_eq<int> ));
  72
  73     BOOST_CHECK ( ba::equal ( input_iterator<int *>(num),     input_iterator<int *>(num + 1),
  74                               input_iterator<int *>(num + 1), input_iterator<int *>(num + 2)));
  75     BOOST_CHECK ( ba::equal ( input_iterator<int *>(num),     input_iterator<int *>(num + 1),
  76                               input_iterator<int *>(num + 1), input_iterator<int *>(num + 2),
  77                               eq<int> ));
  78
  79     BOOST_CHECK (!ba::equal ( input_iterator<int *>(num + 2), input_iterator<int *>(num + 3),
  80                               input_iterator<int *>(num),     input_iterator<int *>(num + 1)));
  81     BOOST_CHECK (!ba::equal ( input_iterator<int *>(num + 2), input_iterator<int *>(num + 3),
  82                               input_iterator<int *>(num),     input_iterator<int *>(num + 1),
  83                               eq<int> ));
  84
  85 //  Identical long sequences are equal.
  86     BOOST_CHECK ( ba::equal ( input_iterator<int *>(num),     input_iterator<int *>(num + sz),
  87                               input_iterator<int *>(num),     input_iterator<int *>(num + sz)));
  88     BOOST_CHECK ( ba::equal ( input_iterator<int *>(num),     input_iterator<int *>(num + sz),
  89                               input_iterator<int *>(num),     input_iterator<int *>(num + sz),
  90                               eq<int> ));
  91     BOOST_CHECK (!ba::equal ( input_iterator<int *>(num),     input_iterator<int *>(num + sz),
  92                               input_iterator<int *>(num),     input_iterator<int *>(num + sz),
  93                               never_eq<int> ));
  94     BOOST_CHECK ( ba::equal ( input_iterator<int *>(num),             input_iterator<int *>(num + sz),
  95                               random_access_iterator<int *>(num),     random_access_iterator<int *>(num + sz),
  96                               eq<int> ));
  97
  98 //  different sequences are different
  99     BOOST_CHECK (!ba::equal ( input_iterator<int *>(num + 1), input_iterator<int *>(num + sz),
 100                               input_iterator<int *>(num),     input_iterator<int *>(num + sz)));
 101     BOOST_CHECK (!ba::equal ( input_iterator<int *>(num + 1), input_iterator<int *>(num + sz),
 102                               input_iterator<int *>(num),     input_iterator<int *>(num + sz),
 103                               eq<int> ));
 104     BOOST_CHECK (!ba::equal ( input_iterator<int *>(num),     input_iterator<int *>(num + sz),
 105                               input_iterator<int *>(num),     input_iterator<int *>(num + sz - 1)));
 106     BOOST_CHECK (!ba::equal ( input_iterator<int *>(num),     input_iterator<int *>(num + sz),
 107                               input_iterator<int *>(num),     input_iterator<int *>(num + sz - 1),
 108                               eq<int> ));
 109
 110 //  When there's a cheap check, bail early
 111     comparison_count = 0;
 112     BOOST_CHECK (!ba::equal ( random_access_iterator<int *>(num),     random_access_iterator<int *>(num + sz),
 113                               random_access_iterator<int *>(num),     random_access_iterator<int *>(num + sz - 1),
 114                               counting_equals<int> ));
 115     BOOST_CHECK ( comparison_count == 0 );
 116 //  And when there's not, we can't
 117     comparison_count = 0;
 118     BOOST_CHECK (!ba::equal ( input_iterator<int *>(num),     input_iterator<int *>(num + sz),
 119                               input_iterator<int *>(num),     input_iterator<int *>(num + sz - 1),
 120                               counting_equals<int> ));
 121     BOOST_CHECK ( comparison_count > 0 );
 122
 123 }
 124
 125
 126 BOOST_AUTO_TEST_CASE( test_main )
 127 {
 128   test_equal ();
 129 }