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//===----------------------------------------------------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
// <algorithm>
// template<RandomAccessIterator Iter>
// requires ShuffleIterator<Iter>
// void
// random_shuffle(Iter first, Iter last);
// REQUIRES: c++03 || c++11 || c++14
// ADDITIONAL_COMPILE_FLAGS: -D_LIBCPP_DISABLE_DEPRECATION_WARNINGS
#include <algorithm>
#include <array>
#include <cassert>
#include "test_macros.h"
#include "test_iterators.h"
template <class Iter>
void
test_with_iterator()
{
std::array<int, 0> empty = {};
std::random_shuffle(Iter(empty.data()), Iter(empty.data()));
const int all_elements[] = {1, 2, 3, 4};
int shuffled[] = {1, 2, 3, 4};
const unsigned size = sizeof(all_elements) / sizeof(all_elements[0]);
std::random_shuffle(Iter(shuffled), Iter(shuffled + size));
assert(std::is_permutation(shuffled, shuffled + size, all_elements));
std::random_shuffle(Iter(shuffled), Iter(shuffled + size));
assert(std::is_permutation(shuffled, shuffled + size, all_elements));
}
int main(int, char**)
{
int ia[] = {1, 2, 3, 4};
int ia1[] = {1, 4, 3, 2};
int ia2[] = {4, 1, 2, 3};
const unsigned sa = sizeof(ia)/sizeof(ia[0]);
std::random_shuffle(ia, ia+sa);
LIBCPP_ASSERT(std::equal(ia, ia+sa, ia1));
assert(std::is_permutation(ia, ia+sa, ia1));
std::random_shuffle(ia, ia+sa);
LIBCPP_ASSERT(std::equal(ia, ia+sa, ia2));
assert(std::is_permutation(ia, ia+sa, ia2));
test_with_iterator<random_access_iterator<int*> >();
test_with_iterator<int*>();
return 0;
}
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