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

107 lines
2.4 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=(const optional<T>& rhs); // constexpr in C++20
#include <optional>
#include <type_traits>
#include <cassert>
#include "test_macros.h"
#include "archetypes.hpp"
using std::optional;
struct X
{
static bool throw_now;
X() = default;
X(const X&)
{
if (throw_now)
TEST_THROW(6);
}
};
bool X::throw_now = false;
template <class Tp>
constexpr bool assign_empty(optional<Tp>&& lhs) {
const optional<Tp> rhs;
lhs = rhs;
return !lhs.has_value() && !rhs.has_value();
}
template <class Tp>
constexpr bool assign_value(optional<Tp>&& lhs) {
const optional<Tp> rhs(101);
lhs = rhs;
return lhs.has_value() && rhs.has_value() && *lhs == *rhs;
}
int main()
{
{
using O = optional<int>;
#if TEST_STD_VER > 17
LIBCPP_STATIC_ASSERT(assign_empty(O{42}), "");
LIBCPP_STATIC_ASSERT(assign_value(O{42}), "");
#endif
assert(assign_empty(O{42}));
assert(assign_value(O{42}));
}
{
using O = optional<TrivialTestTypes::TestType>;
#if TEST_STD_VER > 17
LIBCPP_STATIC_ASSERT(assign_empty(O{42}), "");
LIBCPP_STATIC_ASSERT(assign_value(O{42}), "");
#endif
assert(assign_empty(O{42}));
assert(assign_value(O{42}));
}
{
using O = optional<TestTypes::TestType>;
assert(assign_empty(O{42}));
assert(assign_value(O{42}));
}
{
using T = TestTypes::TestType;
T::reset();
optional<T> opt(3);
const optional<T> opt2;
assert(T::alive == 1);
opt = opt2;
assert(T::alive == 0);
assert(!opt2.has_value());
assert(!opt.has_value());
}
#ifndef TEST_HAS_NO_EXCEPTIONS
{
optional<X> opt;
optional<X> opt2(X{});
assert(static_cast<bool>(opt2) == true);
try
{
X::throw_now = true;
opt = opt2;
assert(false);
}
catch (int i)
{
assert(i == 6);
assert(static_cast<bool>(opt) == false);
}
}
#endif
}