ceph/src/boost/libs/range/test/algorithm_test/random_shuffle.cpp

   1 //  Copyright Neil Groves 2009. Use, modification and
   2 //  distribution is subject to the Boost Software License, Version
   3 //  1.0. (See accompanying file LICENSE_1_0.txt or copy at
   4 //  http://www.boost.org/LICENSE_1_0.txt)
   5 //
   6 //
   7 // For more information, see http://www.boost.org/libs/range/
   8 //
   9 #include <boost/range/algorithm/random_shuffle.hpp>
  10
  11 #include <boost/test/test_tools.hpp>
  12 #include <boost/test/unit_test.hpp>
  13
  14 #include <boost/assign.hpp>
  15 #include <boost/bind.hpp>
  16 #include "../test_function/counted_function.hpp"
  17 #include <algorithm>
  18 #include <functional>
  19 #include <list>
  20 #include <numeric>
  21 #include <deque>
  22 #include <vector>
  23
  24 namespace boost
  25 {
  26     namespace
  27     {
  28         template<class Int>
  29         class counted_generator
  30             : private range_test_function::counted_function
  31         {
  32         public:
  33             typedef Int result_type;
  34             typedef Int argument_type;
  35
  36             using range_test_function::counted_function::invocation_count;
  37
  38             result_type operator()(argument_type modulo_value)
  39             {
  40                 invoked();
  41                 return static_cast<result_type>(std::rand() % modulo_value);
  42             }
  43         };
  44
  45         template<class Container>
  46         bool test_shuffle_result(
  47             const Container& old_cont,
  48             const Container& new_cont
  49             )
  50         {
  51             typedef BOOST_DEDUCED_TYPENAME range_iterator<const Container>::type iterator_t;
  52
  53             // The size must remain equal
  54             BOOST_CHECK_EQUAL( old_cont.size(), new_cont.size() );
  55             if (old_cont.size() != new_cont.size())
  56                 return false;
  57
  58             if (new_cont.size() < 2)
  59             {
  60                 BOOST_CHECK_EQUAL_COLLECTIONS(
  61                     old_cont.begin(), old_cont.end(),
  62                     new_cont.begin(), new_cont.end()
  63                     );
  64
  65                 return std::equal(old_cont.begin(), old_cont.end(),
  66                                   new_cont.begin());
  67             }
  68
  69             // Elements must only be moved around. This is tested by
  70             // ensuring the count of each element remains the
  71             // same.
  72             bool failed = false;
  73             iterator_t last = old_cont.end();
  74             for (iterator_t it = old_cont.begin(); !failed && (it != last); ++it)
  75             {
  76                 const std::size_t old_count
  77                     = std::count(old_cont.begin(), old_cont.end(), *it);
  78
  79                 const std::size_t new_count
  80                     = std::count(new_cont.begin(), new_cont.end(), *it);
  81
  82                 BOOST_CHECK_EQUAL( old_count, new_count );
  83
  84                 failed = (old_count != new_count);
  85             }
  86
  87             return !failed;
  88         }
  89
  90         template<class Container>
  91         void test_random_shuffle_nogen_impl(Container& cont)
  92         {
  93             typedef BOOST_DEDUCED_TYPENAME range_iterator<Container>::type
  94                                                 iterator_t BOOST_RANGE_UNUSED;
  95
  96             const int MAX_RETRIES = 10000;
  97
  98             bool shuffled = false;
  99             for (int attempt = 0; !shuffled && (attempt < MAX_RETRIES); ++attempt)
 100             {
 101                 Container test(cont);
 102                 boost::random_shuffle(test);
 103                 bool ok = test_shuffle_result(cont, test);
 104                 if (!ok)
 105                     break;
 106
 107                 // Since the counts are equal, then if they are
 108                 // not equal the contents must have been shuffled
 109                 if (cont.size() == test.size()
 110                 &&  !std::equal(cont.begin(), cont.end(), test.begin()))
 111                 {
 112                     shuffled = true;
 113                 }
 114
 115                 // Verify that the shuffle can be performed on a
 116                 // temporary range
 117                 Container test2(cont);
 118                 boost::random_shuffle(boost::make_iterator_range(test2));
 119                 ok = test_shuffle_result(cont, test2);
 120                 if (!ok)
 121                     break;
 122             }
 123         }
 124
 125         template<class RandomGenerator, class Container>
 126         void test_random_shuffle_gen_impl(Container& cont)
 127         {
 128             RandomGenerator gen;
 129             Container old_cont(cont);
 130             boost::random_shuffle(cont, gen);
 131             test_shuffle_result(cont, old_cont);
 132             if (cont.size() > 2)
 133             {
 134                 BOOST_CHECK( gen.invocation_count() > 0 );
 135             }
 136
 137             // Test that random shuffle works when
 138             // passed a temporary range
 139             RandomGenerator gen2;
 140             Container cont2(old_cont);
 141             boost::random_shuffle(boost::make_iterator_range(cont2), gen2);
 142             test_shuffle_result(cont2, old_cont);
 143             if (cont2.size() > 2)
 144             {
 145                 BOOST_CHECK( gen2.invocation_count() > 0 );
 146             }
 147         }
 148
 149         template<class Container>
 150         void test_random_shuffle_impl(Container& cont)
 151         {
 152             Container old_cont(cont);
 153             boost::random_shuffle(cont);
 154             test_shuffle_result(cont, old_cont);
 155         }
 156
 157         template<class Container>
 158         void test_random_shuffle_impl()
 159         {
 160             using namespace boost::assign;
 161
 162             typedef counted_generator<
 163                 BOOST_DEDUCED_TYPENAME range_difference<Container>::type > generator_t;
 164
 165             Container cont;
 166             test_random_shuffle_nogen_impl(cont);
 167             test_random_shuffle_gen_impl<generator_t>(cont);
 168
 169             cont.clear();
 170             cont += 1;
 171             test_random_shuffle_nogen_impl(cont);
 172             test_random_shuffle_gen_impl<generator_t>(cont);
 173
 174             cont.clear();
 175             cont += 1,2,3,4,5,6,7,8,9;
 176             test_random_shuffle_nogen_impl(cont);
 177             test_random_shuffle_gen_impl<generator_t>(cont);
 178         }
 179
 180         void test_random_shuffle()
 181         {
 182             test_random_shuffle_impl< std::vector<int> >();
 183             test_random_shuffle_impl< std::deque<int> >();
 184         }
 185     }
 186 }
 187
 188
 189 boost::unit_test::test_suite*
 190 init_unit_test_suite(int argc, char* argv[])
 191 {
 192     boost::unit_test::test_suite* test
 193         = BOOST_TEST_SUITE( "RangeTestSuite.algorithm.random_shuffle" );
 194
 195     test->add( BOOST_TEST_CASE( &boost::test_random_shuffle ) );
 196
 197     return test;
 198 }