//===----------------------------------------------------------------------===//
//
// 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>
// From LWG2451:
// template<class U>
// optional<T>& operator=(const optional<U>& rhs);
#include <optional>
#include <type_traits>
#include <cassert>
#include "test_macros.h"
#include "archetypes.h"
using std::optional;
struct X
{
static bool throw_now;
X() = default;
X(int)
{
if (throw_now)
TEST_THROW(6);
}
};
bool X::throw_now = false;
struct Y1
{
Y1() = default;
Y1(const int&) {}
Y1& operator=(const Y1&) = delete;
};
struct Y2
{
Y2() = default;
Y2(const int&) = delete;
Y2& operator=(const int&) { return *this; }
};
template <class T>
struct AssignableFrom {
static int type_constructed;
static int type_assigned;
static int int_constructed;
static int int_assigned;
static void reset() {
type_constructed = int_constructed = 0;
type_assigned = int_assigned = 0;
}
AssignableFrom() = default;
explicit AssignableFrom(T) { ++type_constructed; }
AssignableFrom& operator=(T) { ++type_assigned; return *this; }
AssignableFrom(int) { ++int_constructed; }
AssignableFrom& operator=(int) { ++int_assigned; return *this; }
private:
AssignableFrom(AssignableFrom const&) = delete;
AssignableFrom& operator=(AssignableFrom const&) = delete;
};
template <class T> int AssignableFrom<T>::type_constructed = 0;
template <class T> int AssignableFrom<T>::type_assigned = 0;
template <class T> int AssignableFrom<T>::int_constructed = 0;
template <class T> int AssignableFrom<T>::int_assigned = 0;
void test_with_test_type() {
using T = TestTypes::TestType;
T::reset();
{ // non-empty to empty
T::reset_constructors();
optional<T> opt;
const optional<int> other(42);
opt = other;
assert(T::alive == 1);
assert(T::constructed == 1);
assert(T::value_constructed == 1);
assert(T::assigned == 0);
assert(T::destroyed == 0);
assert(static_cast<bool>(other) == true);
assert(*other == 42);
assert(static_cast<bool>(opt) == true);
assert(*opt == T(42));
}
assert(T::alive == 0);
{ // non-empty to non-empty
optional<T> opt(101);
const optional<int> other(42);
T::reset_constructors();
opt = other;
assert(T::alive == 1);
assert(T::constructed == 0);
assert(T::assigned == 1);
assert(T::value_assigned == 1);
assert(T::destroyed == 0);
assert(static_cast<bool>(other) == true);
assert(*other == 42);
assert(static_cast<bool>(opt) == true);
assert(*opt == T(42));
}
assert(T::alive == 0);
{ // empty to non-empty
optional<T> opt(101);
const optional<int> other;
T::reset_constructors();
opt = other;
assert(T::alive == 0);
assert(T::constructed == 0);
assert(T::assigned == 0);
assert(T::destroyed == 1);
assert(static_cast<bool>(other) == false);
assert(static_cast<bool>(opt) == false);
}
assert(T::alive == 0);
{ // empty to empty
optional<T> opt;
const optional<int> other;
T::reset_constructors();
opt = other;
assert(T::alive == 0);
assert(T::constructed == 0);
assert(T::assigned == 0);
assert(T::destroyed == 0);
assert(static_cast<bool>(other) == false);
assert(static_cast<bool>(opt) == false);
}
assert(T::alive == 0);
}
void test_ambiguous_assign() {
using OptInt = std::optional<int>;
{
using T = AssignableFrom<OptInt const&>;
const OptInt a(42);
T::reset();
{
std::optional<T> t;
t = a;
assert(T::type_constructed == 1);
assert(T::type_assigned == 0);
assert(T::int_constructed == 0);
assert(T::int_assigned == 0);
}
T::reset();
{
std::optional<T> t(42);
t = a;
assert(T::type_constructed == 0);
assert(T::type_assigned == 1);
assert(T::int_constructed == 1);
assert(T::int_assigned == 0);
}
T::reset();
{
std::optional<T> t(42);
t = std::move(a);
assert(T::type_constructed == 0);
assert(T::type_assigned == 1);
assert(T::int_constructed == 1);
assert(T::int_assigned == 0);
}
}
{
using T = AssignableFrom<OptInt&>;
OptInt a(42);
T::reset();
{
std::optional<T> t;
t = a;
assert(T::type_constructed == 1);
assert(T::type_assigned == 0);
assert(T::int_constructed == 0);
assert(T::int_assigned == 0);
}
{
using Opt = std::optional<T>;
static_assert(!std::is_assignable_v<Opt&, OptInt const&>, "");
}
}
}
int main(int, char**)
{
test_with_test_type();
test_ambiguous_assign();
{
optional<int> opt;
constexpr optional<short> opt2;
opt = opt2;
static_assert(static_cast<bool>(opt2) == false, "");
assert(static_cast<bool>(opt) == static_cast<bool>(opt2));
}
{
optional<int> opt;
constexpr optional<short> opt2(short{2});
opt = opt2;
static_assert(static_cast<bool>(opt2) == true, "");
static_assert(*opt2 == 2, "");
assert(static_cast<bool>(opt) == static_cast<bool>(opt2));
assert(*opt == *opt2);
}
{
optional<int> opt(3);
constexpr optional<short> opt2;
opt = opt2;
static_assert(static_cast<bool>(opt2) == false, "");
assert(static_cast<bool>(opt) == static_cast<bool>(opt2));
}
{
optional<int> opt(3);
constexpr optional<short> opt2(short{2});
opt = opt2;
static_assert(static_cast<bool>(opt2) == true, "");
static_assert(*opt2 == 2, "");
assert(static_cast<bool>(opt) == static_cast<bool>(opt2));
assert(*opt == *opt2);
}
#ifndef TEST_HAS_NO_EXCEPTIONS
{
optional<X> opt;
optional<int> opt2(42);
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
return 0;
}
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