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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
//
//===----------------------------------------------------------------------===//
// <array>
// template <class T, size_t N> void swap(array<T,N>& x, array<T,N>& y);
#include <array>
#include <cassert>
#include <utility>
#include "test_macros.h"
struct NonSwappable {
TEST_CONSTEXPR NonSwappable() {}
private:
NonSwappable(NonSwappable const&);
NonSwappable& operator=(NonSwappable const&);
};
template <class Tp>
decltype(swap(std::declval<Tp>(), std::declval<Tp>())) can_swap_imp(int);
template <class Tp>
std::false_type can_swap_imp(...);
template <class Tp>
struct can_swap : std::is_same<decltype(can_swap_imp<Tp>(0)), void> {};
TEST_CONSTEXPR_CXX20 bool tests() {
{
typedef double T;
typedef std::array<T, 3> C;
C c1 = {1, 2, 3.5};
C c2 = {4, 5, 6.5};
swap(c1, c2);
assert(c1.size() == 3);
assert(c1[0] == 4);
assert(c1[1] == 5);
assert(c1[2] == 6.5);
assert(c2.size() == 3);
assert(c2[0] == 1);
assert(c2[1] == 2);
assert(c2[2] == 3.5);
}
{
typedef double T;
typedef std::array<T, 0> C;
C c1 = {};
C c2 = {};
swap(c1, c2);
assert(c1.size() == 0);
assert(c2.size() == 0);
}
{
typedef NonSwappable T;
typedef std::array<T, 0> C0;
static_assert(can_swap<C0&>::value, "");
C0 l = {};
C0 r = {};
swap(l, r);
#if TEST_STD_VER >= 11
static_assert(noexcept(swap(l, r)), "");
#endif
}
#if TEST_STD_VER >= 11
{
// NonSwappable is still considered swappable in C++03 because there
// is no access control SFINAE.
typedef NonSwappable T;
typedef std::array<T, 42> C1;
static_assert(!can_swap<C1&>::value, "");
}
#endif
return true;
}
int main(int, char**) {
tests();
#if TEST_STD_VER >= 20
static_assert(tests(), "");
#endif
return 0;
}
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