1// Copyright (C) 2005-2015 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// 25.3.9 [lib.alg.permutation.generators]
19
20#include <algorithm>
21#include <testsuite_hooks.h>
22#include <testsuite_iterators.h>
23
24using __gnu_test::test_container;
25using __gnu_test::bidirectional_iterator_wrapper;
26using std::next_permutation;
27
28typedef test_container<int, bidirectional_iterator_wrapper> Container;
29
30void
31test1()
32{
33  // Note: The standard is unclear on what should happen in this case.
34  // This seems the only really sensible behaviour, and what is done.
35  int array[] = {0};
36  Container con(array, array);
37  VERIFY(!next_permutation(con.begin(), con.end()));
38}
39
40void
41test2()
42{
43  int array[] = {0};
44  Container con(array, array + 1);
45  VERIFY(!next_permutation(con.begin(), con.end()));
46}
47
48void
49test3()
50{
51  int array[] = {0, 3};
52  Container con(array, array + 2);
53  VERIFY(next_permutation(con.begin(), con.end()));
54  VERIFY(array[0] == 3 && array[1] == 0);
55  VERIFY(!next_permutation(con.begin(), con.end()));
56  VERIFY(array[0] == 0 && array[1] == 3);
57}
58
59void
60test4()
61{
62  int array[6] = {0, 1, 2, 3, 4, 5};
63  Container con(array, array + 6);
64  for(int i = 0 ; i < 719; ++i)
65    {
66      int temp_array[6];
67      std::copy(array, array + 6, temp_array);
68      VERIFY(next_permutation(array, array + 6));
69      VERIFY(std::lexicographical_compare(temp_array, temp_array + 6,
70					  array, array + 6));
71    }
72  VERIFY(!next_permutation(array,array + 6));
73  for(int i = 0; i < 6; ++i)
74    VERIFY(array[i] == i);
75}
76
77int main()
78{
79  test1();
80  test2();
81  test3();
82  test4();
83}
84