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libcxx/test/std/utilities/optional/optional.object/optional.object.assign/nullopt_t.pass.cpp

68 lines
1.7 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.
//
//===----------------------------------------------------------------------===//
// UNSUPPORTED: c++98, c++03, c++11, c++14
// <optional>
// optional<T>& operator=(nullopt_t) noexcept;
#include <optional>
#include <type_traits>
#include <cassert>
#include "test_macros.h"
#include "archetypes.hpp"
using std::optional;
using std::nullopt_t;
using std::nullopt;
int main()
{
{
optional<int> opt;
static_assert(noexcept(opt = nullopt) == true, "");
opt = nullopt;
assert(static_cast<bool>(opt) == false);
}
{
optional<int> opt(3);
opt = nullopt;
assert(static_cast<bool>(opt) == false);
}
using TT = TestTypes::TestType;
TT::reset();
{
optional<TT> opt;
static_assert(noexcept(opt = nullopt) == true, "");
assert(TT::destroyed == 0);
opt = nullopt;
assert(TT::constructed == 0);
assert(TT::alive == 0);
assert(TT::destroyed == 0);
assert(static_cast<bool>(opt) == false);
}
assert(TT::alive == 0);
assert(TT::destroyed == 0);
TT::reset();
{
optional<TT> opt(42);
assert(TT::destroyed == 0);
TT::reset_constructors();
opt = nullopt;
assert(TT::constructed == 0);
assert(TT::alive == 0);
assert(TT::destroyed == 1);
assert(static_cast<bool>(opt) == false);
}
assert(TT::alive == 0);
assert(TT::destroyed == 1);
TT::reset();
}