1 //===----------------------------------------------------------------------===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8
9 // <algorithm>
10
11 // template<ForwardIterator Iter>
12 // requires LessThanComparable<Iter::value_type>
13 // pair<Iter, Iter>
14 // minmax_element(Iter first, Iter last);
15
16 #include <algorithm>
17 #include <random>
18 #include <cassert>
19
20 #include "test_macros.h"
21 #include "test_iterators.h"
22
23 std::mt19937 randomness;
24
25 template <class Iter>
26 void
test(Iter first,Iter last)27 test(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
45 template <class Iter>
46 void
test(int N)47 test(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
57 template <class Iter>
58 void
test()59 test()
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
81 constexpr int il[] = { 2, 4, 6, 8, 7, 5, 3, 1 };
82 #endif
83
constexpr_test()84 void 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
main(int,char **)93 int main(int, char**)
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 return 0;
103 }
104