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