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