libcxx/test/std/algorithms/alg.modifying.operations/alg.random.shuffle/random_shuffle_rand.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<RandomAccessIterator Iter, Callable<auto, Iter::difference_type> Rand>
  12 //   requires ShuffleIterator<Iter>
  13 //         && Convertible<Rand::result_type, Iter::difference_type>
  14 //   void
  15 //   random_shuffle(Iter first, Iter last, Rand&& rand);
  16
  17 // REQUIRES: c++03 || c++11 || c++14
  18 // ADDITIONAL_COMPILE_FLAGS: -D_LIBCPP_DISABLE_DEPRECATION_WARNINGS
  19
  20 #include <algorithm>
  21 #include <cassert>
  22 #include <cstddef>
  23
  24 #include "test_macros.h"
  25 #include "test_iterators.h"
  26
  27
  28 struct gen
  29 {
  30     std::ptrdiff_t operator()(std::ptrdiff_t n)
  31     {
  32         return n-1;
  33     }
  34 };
  35
  36
  37 template <class Iter>
  38 void
  39 test_with_iterator()
  40 {
  41
  42     int ia[] = {1, 2, 3, 4};
  43     int ia1[] = {4, 1, 2, 3};
  44     const unsigned sa = sizeof(ia)/sizeof(ia[0]);
  45     gen r;
  46
  47     std::random_shuffle(ia, ia+sa, r);
  48     LIBCPP_ASSERT(std::equal(ia, ia+sa, ia1));
  49     assert(std::is_permutation(ia, ia+sa, ia1));
  50
  51     std::random_shuffle(ia, ia+sa, r);
  52     assert(std::is_permutation(ia, ia+sa, ia1));
  53 }
  54
  55
  56 int main(int, char**)
  57 {
  58     test_with_iterator<random_access_iterator<int*> >();
  59     test_with_iterator<int*>();
  60     return 0;
  61 }