Files
Zoe Carver 7a62bee611 [libc++] Implement std::experimental::observer_ptr
This patch adds std::experimental::observer_ptr (n4282) and also
fixes LWG2516.

Co-Authored-By: Louis Dionne <ldionne.2@gmail.com>
Differential Revision: https://reviews.llvm.org/D63230
2023-11-05 17:59:04 -07:00

51 lines
1.1 KiB
C++

// -*- C++ -*-
//===----------------------------------------------------------------------===//
//
// 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
// REQUIRES: c++experimental
// <experimental/memory>
// observer_ptr
//
// constexpr element_type* get() const noexcept;
#include <experimental/memory>
#include <type_traits>
#include <cassert>
template <class T, class Object = T>
constexpr void test_get() {
using Ptr = std::experimental::observer_ptr<T>;
Object obj;
Ptr const ptr(&obj);
assert(ptr.get() == &obj);
static_assert(noexcept(ptr.get()));
static_assert(std::is_same<decltype(ptr.get()), T*>::value);
}
struct Bar {};
constexpr bool test() {
test_get<Bar>();
test_get<int>();
test_get<void, int>();
return true;
}
int main(int, char**) {
test();
static_assert(test());
return 0;
}