| // <experimental/memory> -*- C++ -*- |
| |
| // Copyright (C) 2015-2021 Free Software Foundation, Inc. |
| // |
| // This file is part of the GNU ISO C++ Library. This library is free |
| // software; you can redistribute it and/or modify it under the |
| // terms of the GNU General Public License as published by the |
| // Free Software Foundation; either version 3, or (at your option) |
| // any later version. |
| |
| // This library is distributed in the hope that it will be useful, |
| // but WITHOUT ANY WARRANTY; without even the implied warranty of |
| // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| // GNU General Public License for more details. |
| |
| // Under Section 7 of GPL version 3, you are granted additional |
| // permissions described in the GCC Runtime Library Exception, version |
| // 3.1, as published by the Free Software Foundation. |
| |
| // You should have received a copy of the GNU General Public License and |
| // a copy of the GCC Runtime Library Exception along with this program; |
| // see the files COPYING3 and COPYING.RUNTIME respectively. If not, see |
| // <http://www.gnu.org/licenses/>. |
| |
| /** @file experimental/memory |
| * This is a TS C++ Library header. |
| * @ingroup libfund-ts |
| */ |
| |
| // |
| // N4336 Working Draft, C++ Extensions for Library Fundamentals, Version 2 |
| // |
| |
| #ifndef _GLIBCXX_EXPERIMENTAL_MEMORY |
| #define _GLIBCXX_EXPERIMENTAL_MEMORY 1 |
| |
| #pragma GCC system_header |
| |
| #if __cplusplus >= 201402L |
| |
| #include <memory> |
| #include <type_traits> |
| #include <experimental/bits/shared_ptr.h> |
| #include <bits/functional_hash.h> |
| |
| namespace std _GLIBCXX_VISIBILITY(default) |
| { |
| _GLIBCXX_BEGIN_NAMESPACE_VERSION |
| |
| namespace experimental |
| { |
| inline namespace fundamentals_v2 |
| { |
| #define __cpp_lib_experimental_observer_ptr 201411 |
| |
| template <typename _Tp> |
| class observer_ptr |
| { |
| public: |
| // publish our template parameter and variations thereof |
| using element_type = _Tp; |
| using __pointer = add_pointer_t<_Tp>; // exposition-only |
| using __reference = add_lvalue_reference_t<_Tp>; // exposition-only |
| |
| // 3.2.2, observer_ptr constructors |
| // default c'tor |
| constexpr observer_ptr() noexcept |
| : __t() |
| { } |
| |
| // pointer-accepting c'tors |
| constexpr observer_ptr(nullptr_t) noexcept |
| : __t() |
| { } |
| |
| constexpr explicit observer_ptr(__pointer __p) noexcept |
| : __t(__p) |
| { } |
| |
| // copying c'tors (in addition to compiler-generated copy c'tor) |
| template <typename _Up, |
| typename = typename enable_if< |
| is_convertible<typename add_pointer<_Up>::type, __pointer |
| >::value |
| >::type> |
| constexpr observer_ptr(observer_ptr<_Up> __p) noexcept |
| : __t(__p.get()) |
| { |
| } |
| |
| // 3.2.3, observer_ptr observers |
| constexpr __pointer |
| get() const noexcept |
| { |
| return __t; |
| } |
| |
| constexpr __reference |
| operator*() const |
| { |
| return *get(); |
| } |
| |
| constexpr __pointer |
| operator->() const noexcept |
| { |
| return get(); |
| } |
| |
| constexpr explicit operator bool() const noexcept |
| { |
| return get() != nullptr; |
| } |
| |
| // 3.2.4, observer_ptr conversions |
| constexpr explicit operator __pointer() const noexcept |
| { |
| return get(); |
| } |
| |
| // 3.2.5, observer_ptr modifiers |
| constexpr __pointer |
| release() noexcept |
| { |
| __pointer __tmp = get(); |
| reset(); |
| return __tmp; |
| } |
| |
| constexpr void |
| reset(__pointer __p = nullptr) noexcept |
| { |
| __t = __p; |
| } |
| |
| constexpr void |
| swap(observer_ptr& __p) noexcept |
| { |
| std::swap(__t, __p.__t); |
| } |
| |
| private: |
| __pointer __t; |
| }; // observer_ptr<> |
| |
| template<typename _Tp> |
| void |
| swap(observer_ptr<_Tp>& __p1, observer_ptr<_Tp>& __p2) noexcept |
| { |
| __p1.swap(__p2); |
| } |
| |
| template<typename _Tp> |
| observer_ptr<_Tp> |
| make_observer(_Tp* __p) noexcept |
| { |
| return observer_ptr<_Tp>(__p); |
| } |
| |
| template<typename _Tp, typename _Up> |
| bool |
| operator==(observer_ptr<_Tp> __p1, observer_ptr<_Up> __p2) |
| { |
| return __p1.get() == __p2.get(); |
| } |
| |
| template<typename _Tp, typename _Up> |
| bool |
| operator!=(observer_ptr<_Tp> __p1, observer_ptr<_Up> __p2) |
| { |
| return !(__p1 == __p2); |
| } |
| |
| template<typename _Tp> |
| bool |
| operator==(observer_ptr<_Tp> __p, nullptr_t) noexcept |
| { |
| return !__p; |
| } |
| |
| template<typename _Tp> |
| bool |
| operator==(nullptr_t, observer_ptr<_Tp> __p) noexcept |
| { |
| return !__p; |
| } |
| |
| template<typename _Tp> |
| bool |
| operator!=(observer_ptr<_Tp> __p, nullptr_t) noexcept |
| { |
| return bool(__p); |
| } |
| |
| template<typename _Tp> |
| bool |
| operator!=(nullptr_t, observer_ptr<_Tp> __p) noexcept |
| { |
| return bool(__p); |
| } |
| |
| template<typename _Tp, typename _Up> |
| bool |
| operator<(observer_ptr<_Tp> __p1, observer_ptr<_Up> __p2) |
| { |
| return std::less<typename common_type<typename add_pointer<_Tp>::type, |
| typename add_pointer<_Up>::type |
| >::type |
| >{}(__p1.get(), __p2.get()); |
| } |
| |
| template<typename _Tp, typename _Up> |
| bool |
| operator>(observer_ptr<_Tp> __p1, observer_ptr<_Up> __p2) |
| { |
| return __p2 < __p1; |
| } |
| |
| template<typename _Tp, typename _Up> |
| bool |
| operator<=(observer_ptr<_Tp> __p1, observer_ptr<_Up> __p2) |
| { |
| return !(__p2 < __p1); |
| } |
| |
| template<typename _Tp, typename _Up> |
| bool |
| operator>=(observer_ptr<_Tp> __p1, observer_ptr<_Up> __p2) |
| { |
| return !(__p1 < __p2); |
| } |
| } // namespace fundamentals_v2 |
| } // namespace experimental |
| |
| template <typename _Tp> |
| struct hash<experimental::observer_ptr<_Tp>> |
| { |
| using result_type = size_t; |
| using argument_type = experimental::observer_ptr<_Tp>; |
| |
| size_t |
| operator()(const experimental::observer_ptr<_Tp>& __t) const |
| noexcept(noexcept(hash<typename add_pointer<_Tp>::type> {}(__t.get()))) |
| { |
| return hash<typename add_pointer<_Tp>::type> {}(__t.get()); |
| } |
| }; |
| |
| |
| _GLIBCXX_END_NAMESPACE_VERSION |
| } // namespace std |
| |
| #endif // __cplusplus <= 201103L |
| |
| #endif // _GLIBCXX_EXPERIMENTAL_MEMORY |