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<RandomAccessIterator Iter, Callable<auto, Iter::difference_type> Rand>
13 // requires ShuffleIterator<Iter>
14 // && Convertible<Rand::result_type, Iter::difference_type>
15 // void
16 // random_shuffle(Iter first, Iter last, Rand&& rand);
17
18 #include <algorithm>
19 #include <cassert>
20 #include <cstddef>
21
22 #include "test_macros.h"
23
24 struct gen
25 {
operator ()gen26 std::ptrdiff_t operator()(std::ptrdiff_t n)
27 {
28 return n-1;
29 }
30 };
31
main()32 int main()
33 {
34 int ia[] = {1, 2, 3, 4};
35 int ia1[] = {4, 1, 2, 3};
36 const unsigned sa = sizeof(ia)/sizeof(ia[0]);
37 gen r;
38 std::random_shuffle(ia, ia+sa, r);
39 LIBCPP_ASSERT(std::equal(ia, ia+sa, ia1));
40 assert(std::is_permutation(ia, ia+sa, ia1));
41 }
42