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<InputIterator Iter, class T>
13 //   requires HasEqualTo<Iter::value_type, T>
14 //   constexpr Iter::difference_type   // constexpr after C++17
15 //   count(Iter first, Iter last, const T& value);
16 
17 #include <algorithm>
18 #include <cassert>
19 
20 #include "test_macros.h"
21 #include "test_iterators.h"
22 
23 #if TEST_STD_VER > 17
test_constexpr()24 TEST_CONSTEXPR bool test_constexpr() {
25     int ia[] = {0, 1, 2, 2, 0, 1, 2, 3};
26     int ib[] = {1, 2, 3, 4, 5, 6};
27     return    (std::count(std::begin(ia), std::end(ia), 2) == 3)
28            && (std::count(std::begin(ib), std::end(ib), 9) == 0)
29            ;
30     }
31 #endif
32 
main()33 int main()
34 {
35     int ia[] = {0, 1, 2, 2, 0, 1, 2, 3};
36     const unsigned sa = sizeof(ia)/sizeof(ia[0]);
37     assert(std::count(input_iterator<const int*>(ia),
38                       input_iterator<const int*>(ia + sa), 2) == 3);
39     assert(std::count(input_iterator<const int*>(ia),
40                       input_iterator<const int*>(ia + sa), 7) == 0);
41     assert(std::count(input_iterator<const int*>(ia),
42                       input_iterator<const int*>(ia), 2) == 0);
43 
44 #if TEST_STD_VER > 17
45     static_assert(test_constexpr());
46 #endif
47 }
48