//===----------------------------------------------------------------------===//
//
// 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
//
//===----------------------------------------------------------------------===//
// UNSUPPORTED: 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.h"
using std::optional;
using std::nullopt_t;
using std::nullopt;
TEST_CONSTEXPR_CXX20 bool test()
{
enum class State { inactive, constructed, destroyed };
State state = State::inactive;
struct StateTracker {
TEST_CONSTEXPR_CXX20 StateTracker(State& s)
: state_(&s)
{
s = State::constructed;
}
TEST_CONSTEXPR_CXX20 ~StateTracker() { *state_ = State::destroyed; }
State* state_;
};
{
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);
}
{
optional<StateTracker> opt;
opt = nullopt;
assert(state == State::inactive);
assert(static_cast<bool>(opt) == false);
}
{
optional<StateTracker> opt(state);
assert(state == State::constructed);
opt = nullopt;
assert(state == State::destroyed);
assert(static_cast<bool>(opt) == false);
}
return true;
}
int main(int, char**)
{
#if TEST_STD_VER > 17
static_assert(test());
#endif
test();
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();
return 0;
}