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 // REQUIRES: c++98 || c++03 || c++11 || c++14
12
13 // template<RandomAccessIterator Iter, Callable<auto, Iter::difference_type> Rand>
14 // requires ShuffleIterator<Iter>
15 // && Convertible<Rand::result_type, Iter::difference_type>
16 // void
17 // random_shuffle(Iter first, Iter last, Rand&& rand);
18
19 #include <algorithm>
20 #include <cassert>
21 #include <cstddef>
22
23 #include "test_macros.h"
24
25 struct gen
26 {
operator ()gen27 std::ptrdiff_t operator()(std::ptrdiff_t n)
28 {
29 return n-1;
30 }
31 };
32
main()33 int main()
34 {
35 int ia[] = {1, 2, 3, 4};
36 int ia1[] = {4, 1, 2, 3};
37 const unsigned sa = sizeof(ia)/sizeof(ia[0]);
38 gen r;
39 std::random_shuffle(ia, ia+sa, r);
40 LIBCPP_ASSERT(std::equal(ia, ia+sa, ia1));
41 assert(std::is_permutation(ia, ia+sa, ia1));
42 }
43