libcxx/test/std/algorithms/alg.modifying.operations/alg.random.shuffle/random_shuffle_urng.pass.cpp

   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<class RandomAccessIterator, class UniformRandomNumberGenerator>
  12 //     void shuffle(RandomAccessIterator first, RandomAccessIterator last,
  13 //                  UniformRandomNumberGenerator& g);
  14
  15 #include <algorithm>
  16 #include <cassert>
  17 #include <random>
  18 #include <utility>
  19
  20 #include "test_macros.h"
  21
  22 int main(int, char**)
  23 {
  24     int ia[] = {1, 2, 3, 4, 5, 6, 7, 8, 9, 10};
  25     int ia1[] = {2, 7, 1, 4, 3, 6, 5, 10, 9, 8};
  26     int ia2[] = {1, 8, 3, 4, 6, 9, 5, 7, 2, 10};
  27     const unsigned sa = sizeof(ia)/sizeof(ia[0]);
  28     std::minstd_rand g;
  29     std::shuffle(ia, ia+sa, g);
  30     LIBCPP_ASSERT(std::equal(ia, ia+sa, ia1));
  31     assert(std::is_permutation(ia, ia+sa, ia1));
  32     std::shuffle(ia, ia+sa, std::move(g));
  33     LIBCPP_ASSERT(std::equal(ia, ia+sa, ia2));
  34     assert(std::is_permutation(ia, ia+sa, ia2));
  35
  36   return 0;
  37 }