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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
#include <type_traits>
#include <utility>
#include <vector>
#include "test_macros.h"
namespace MyNS {
// Make the test types non-copyable so that generic std::swap is not valid.
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 {
M(M const&) = delete;
M& operator=(M const&) = delete;
};
void swap(M&&, M&&) {}
struct DeletedSwap {
friend void swap(DeletedSwap&, DeletedSwap&) = delete;
};
} // namespace MyNS
namespace MyNS2 {
struct AmbiguousSwap {};
template <class T>
void swap(T&, T&) {}
} // end namespace MyNS2
int main()
{
using namespace MyNS;
{
// Test that is_swappable applies an lvalue reference to the type.
static_assert(std::is_swappable<A>::value, "");
static_assert(std::is_swappable<A&>::value, "");
static_assert(!std::is_swappable<M>::value, "");
static_assert(!std::is_swappable<M&&>::value, "");
}
static_assert(!std::is_swappable<B>::value, "");
static_assert(std::is_swappable<C>::value, "");
{
// test non-referencable types
static_assert(!std::is_swappable<void>::value, "");
static_assert(!std::is_swappable<int() const>::value, "");
static_assert(!std::is_swappable<int() &>::value, "");
}
{
// test that a deleted swap is correctly handled.
static_assert(!std::is_swappable<DeletedSwap>::value, "");
}
{
// test that a swap with ambiguous overloads is handled correctly.
static_assert(!std::is_swappable<MyNS2::AmbiguousSwap>::value, "");
}
{
// test for presence of is_swappable_v
static_assert(std::is_swappable_v<int>, "");
static_assert(!std::is_swappable_v<M>, "");
}
}
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