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//===----------------------------------------------------------------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is dual licensed under the MIT and the University of Illinois Open
// Source Licenses. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
// UNSUPPORTED: c++98, c++03, c++11, c++14
// type_traits
// is_swappable_with
#include <type_traits>
#include <vector>
#include "test_macros.h"
namespace MyNS {
struct A {
A(A const&) = delete;
A& operator=(A const&) = delete;
};
struct B {
B(B const&) = delete;
B& operator=(B const&) = delete;
};
struct C {};
struct D {};
void swap(A&, A&) {}
void swap(A&, B&) {}
void swap(B&, A&) {}
void swap(A&, C&) {} // missing swap(C, A)
void swap(D&, C&) {}
struct M {};
void swap(M&&, M&&) {}
} // namespace MyNS
int main()
{
using namespace MyNS;
{
// Test that is_swappable_with doesn't apply an lvalue reference
// to the type. Instead it is up to the user.
static_assert(!std::is_swappable_with<int, int>::value, "");
static_assert(std::is_swappable_with<int&, int&>::value, "");
static_assert(std::is_swappable_with<M, M>::value, "");
static_assert(std::is_swappable_with<A&, A&>::value, "");
}
{
// test that heterogeneous swap is allowed only if both 'swap(A, B)' and
// 'swap(B, A)' are valid.
static_assert(std::is_swappable_with<A&, B&>::value, "");
static_assert(!std::is_swappable_with<A&, C&>::value, "");
static_assert(!std::is_swappable_with<D&, C&>::value, "");
}
{
// test that cv void is guarded against as required.
static_assert(!std::is_swappable_with_v<void, int>, "");
static_assert(!std::is_swappable_with_v<int, void>, "");
static_assert(!std::is_swappable_with_v<const void, const volatile void>, "");
}
{
// test for presence of is_swappable_with_v
static_assert(std::is_swappable_with_v<int&, int&>, "");
static_assert(!std::is_swappable_with_v<D&, C&>, "");
}
}
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