1//===----------------------------------------------------------------------===//
2//
3//                     The LLVM Compiler Infrastructure
4//
5// This file is dual licensed under the MIT and the University of Illinois Open
6// Source Licenses. See LICENSE.TXT for details.
7//
8//===----------------------------------------------------------------------===//
9
10// <algorithm>
11
12// template<ForwardIterator Iter>
13//   requires LessThanComparable<Iter::value_type>
14//   pair<Iter, Iter>
15//   minmax_element(Iter first, Iter last);
16
17#include <algorithm>
18#include <random>
19#include <cassert>
20
21#include "test_iterators.h"
22
23std::mt19937 randomness;
24
25template <class Iter>
26void
27test(Iter first, Iter last)
28{
29    std::pair<Iter, Iter> p = std::minmax_element(first, last);
30    if (first != last)
31    {
32        for (Iter j = first; j != last; ++j)
33        {
34            assert(!(*j < *p.first));
35            assert(!(*p.second < *j));
36        }
37    }
38    else
39    {
40        assert(p.first == last);
41        assert(p.second == last);
42    }
43}
44
45template <class Iter>
46void
47test(int N)
48{
49    int* a = new int[N];
50    for (int i = 0; i < N; ++i)
51        a[i] = i;
52    std::shuffle(a, a+N, randomness);
53    test(Iter(a), Iter(a+N));
54    delete [] a;
55}
56
57template <class Iter>
58void
59test()
60{
61    test<Iter>(0);
62    test<Iter>(1);
63    test<Iter>(2);
64    test<Iter>(3);
65    test<Iter>(10);
66    test<Iter>(1000);
67    {
68    const int N = 100;
69    int* a = new int[N];
70    for (int i = 0; i < N; ++i)
71        a[i] = 5;
72    std::shuffle(a, a+N, randomness);
73    std::pair<Iter, Iter> p = std::minmax_element(Iter(a), Iter(a+N));
74    assert(base(p.first) == a);
75    assert(base(p.second) == a+N-1);
76    delete [] a;
77    }
78}
79
80#if TEST_STD_VER >= 14
81constexpr int il[] = { 2, 4, 6, 8, 7, 5, 3, 1 };
82#endif
83
84void constexpr_test()
85{
86#if TEST_STD_VER >= 14
87    constexpr auto p = std::minmax_element(il, il+8);
88    static_assert ( *(p.first)  == 1, "" );
89    static_assert ( *(p.second) == 8, "" );
90#endif
91}
92
93int main()
94{
95    test<forward_iterator<const int*> >();
96    test<bidirectional_iterator<const int*> >();
97    test<random_access_iterator<const int*> >();
98    test<const int*>();
99
100   constexpr_test();
101}
102