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 // REQUIRES: c++98 || c++03 || c++11 || c++14 11 12 // template<RandomAccessIterator Iter> 13 // requires ShuffleIterator<Iter> 14 // void 15 // random_shuffle(Iter first, Iter last); 16 17 #include <algorithm> 18 #include <cassert> 19 20 #include "test_macros.h" 21 #include "test_iterators.h" 22 23 template <class Iter> 24 void 25 test_with_iterator() 26 { 27 int empty[] = {}; 28 std::random_shuffle(Iter(empty), Iter(empty)); 29 30 const int all_elements[] = {1, 2, 3, 4}; 31 int shuffled[] = {1, 2, 3, 4}; 32 const unsigned size = sizeof(all_elements)/sizeof(all_elements[0]); 33 34 std::random_shuffle(Iter(shuffled), Iter(shuffled+size)); 35 assert(std::is_permutation(shuffled, shuffled+size, all_elements)); 36 37 std::random_shuffle(Iter(shuffled), Iter(shuffled+size)); 38 assert(std::is_permutation(shuffled, shuffled+size, all_elements)); 39 } 40 41 42 int main(int, char**) 43 { 44 int ia[] = {1, 2, 3, 4}; 45 int ia1[] = {1, 4, 3, 2}; 46 int ia2[] = {4, 1, 2, 3}; 47 const unsigned sa = sizeof(ia)/sizeof(ia[0]); 48 49 std::random_shuffle(ia, ia+sa); 50 LIBCPP_ASSERT(std::equal(ia, ia+sa, ia1)); 51 assert(std::is_permutation(ia, ia+sa, ia1)); 52 53 std::random_shuffle(ia, ia+sa); 54 LIBCPP_ASSERT(std::equal(ia, ia+sa, ia2)); 55 assert(std::is_permutation(ia, ia+sa, ia2)); 56 57 test_with_iterator<random_access_iterator<int*> >(); 58 test_with_iterator<int*>(); 59 60 return 0; 61 } 62