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
21struct gen
22{
23    int operator()(int n)
24    {
25        return n-1;
26    }
27};
28
29int main()
30{
31    int ia[] = {1, 2, 3, 4};
32    int ia1[] = {4, 1, 2, 3};
33    const unsigned sa = sizeof(ia)/sizeof(ia[0]);
34    gen r;
35    std::random_shuffle(ia, ia+sa, r);
36    assert(std::equal(ia, ia+sa, ia1));
37}
38