op_arrow.pass.cpp
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//===----------------------------------------------------------------------===//
//
// 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>
// constexpr T* optional<T>::operator->();
#ifdef _LIBCPP_DEBUG
#define _LIBCPP_ASSERT(x, m) ((x) ? (void)0 : std::exit(0))
#endif
#include <optional>
#include <type_traits>
#include <cassert>
#include "test_macros.h"
using std::optional;
struct X
{
int test() noexcept {return 3;}
};
struct Y
{
constexpr int test() {return 3;}
};
constexpr int
test()
{
optional<Y> opt{Y{}};
return opt->test();
}
int main(int, char**)
{
{
std::optional<X> opt; ((void)opt);
ASSERT_SAME_TYPE(decltype(opt.operator->()), X*);
// ASSERT_NOT_NOEXCEPT(opt.operator->());
// FIXME: This assertion fails with GCC because it can see that
// (A) operator->() is constexpr, and
// (B) there is no path through the function that throws.
// It's arguable if this is the correct behavior for the noexcept
// operator.
// Regardless this function should still be noexcept(false) because
// it has a narrow contract.
}
{
optional<X> opt(X{});
assert(opt->test() == 3);
}
{
static_assert(test() == 3, "");
}
#ifdef _LIBCPP_DEBUG
{
optional<X> opt;
assert(opt->test() == 3);
assert(false);
}
#endif // _LIBCPP_DEBUG
return 0;
}