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libcxx/test/std/utilities/tuple/tuple.general/ignore.pass.cpp

55 lines
1.3 KiB
C++

//===----------------------------------------------------------------------===//
//
// 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.
//
//===----------------------------------------------------------------------===//
// <tuple>
// constexpr unspecified ignore;
// UNSUPPORTED: c++98, c++03
#include <tuple>
#include <cassert>
#include "test_macros.h"
constexpr bool test_ignore_constexpr()
{
#if TEST_STD_VER > 11
{ // Test that std::ignore provides constexpr converting assignment.
auto& res = (std::ignore = 42);
assert(&res == &std::ignore);
}
{ // Test that std::ignore provides constexpr copy/move constructors
auto copy = std::ignore;
auto moved = std::move(copy);
((void)moved);
}
{ // Test that std::ignore provides constexpr copy/move assignment
auto copy = std::ignore;
copy = std::ignore;
auto moved = std::ignore;
moved = std::move(copy);
}
#endif
return true;
}
int main() {
{
constexpr auto& ignore_v = std::ignore;
((void)ignore_v);
}
{
static_assert(test_ignore_constexpr(), "");
}
{
LIBCPP_STATIC_ASSERT(std::is_trivial<decltype(std::ignore)>::value, "");
}
}