--- /dev/null
+// shared_ptr and weak_ptr implementation details -*- C++ -*-
+
+// Copyright (C) 2007, 2008, 2009, 2010, 2011, 2012
+// 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/>.
+
+// GCC Note: Based on files from version 1.32.0 of the Boost library.
+
+// shared_count.hpp
+// Copyright (c) 2001, 2002, 2003 Peter Dimov and Multi Media Ltd.
+
+// shared_ptr.hpp
+// Copyright (C) 1998, 1999 Greg Colvin and Beman Dawes.
+// Copyright (C) 2001, 2002, 2003 Peter Dimov
+
+// weak_ptr.hpp
+// Copyright (C) 2001, 2002, 2003 Peter Dimov
+
+// enable_shared_from_this.hpp
+// Copyright (C) 2002 Peter Dimov
+
+// Distributed under the Boost Software License, Version 1.0. (See
+// accompanying file LICENSE_1_0.txt or copy at
+// http://www.boost.org/LICENSE_1_0.txt)
+
+/** @file bits/shared_ptr_base.h
+ * This is an internal header file, included by other library headers.
+ * Do not attempt to use it directly. @headername{memory}
+ */
+
+#ifndef _SHARED_PTR_BASE_H
+#define _SHARED_PTR_BASE_H 1
+
+namespace std _GLIBCXX_VISIBILITY(default)
+{
+_GLIBCXX_BEGIN_NAMESPACE_VERSION
+
+ /**
+ * @brief Exception possibly thrown by @c shared_ptr.
+ * @ingroup exceptions
+ */
+ class bad_weak_ptr : public std::exception
+ {
+ public:
+ virtual char const*
+ what() const noexcept;
+
+ virtual ~bad_weak_ptr() noexcept;
+ };
+
+ // Substitute for bad_weak_ptr object in the case of -fno-exceptions.
+ inline void
+ __throw_bad_weak_ptr()
+ {
+#if __EXCEPTIONS
+ throw bad_weak_ptr();
+#else
+ __builtin_abort();
+#endif
+ }
+
+ using __gnu_cxx::_Lock_policy;
+ using __gnu_cxx::__default_lock_policy;
+ using __gnu_cxx::_S_single;
+ using __gnu_cxx::_S_mutex;
+ using __gnu_cxx::_S_atomic;
+
+ // Empty helper class except when the template argument is _S_mutex.
+ template<_Lock_policy _Lp>
+ class _Mutex_base
+ {
+ protected:
+ // The atomic policy uses fully-fenced builtins, single doesn't care.
+ enum { _S_need_barriers = 0 };
+ };
+
+ template<>
+ class _Mutex_base<_S_mutex>
+ : public __gnu_cxx::__mutex
+ {
+ protected:
+ // This policy is used when atomic builtins are not available.
+ // The replacement atomic operations might not have the necessary
+ // memory barriers.
+ enum { _S_need_barriers = 1 };
+ };
+
+ template<_Lock_policy _Lp = __default_lock_policy>
+ class _Sp_counted_base
+ : public _Mutex_base<_Lp>
+ {
+ public:
+ _Sp_counted_base() noexcept
+ : _M_use_count(1), _M_weak_count(1) { }
+
+ virtual
+ ~_Sp_counted_base() noexcept
+ { }
+
+ // Called when _M_use_count drops to zero, to release the resources
+ // managed by *this.
+ virtual void
+ _M_dispose() noexcept = 0;
+
+ // Called when _M_weak_count drops to zero.
+ virtual void
+ _M_destroy() noexcept
+ { delete this; }
+
+ virtual void*
+ _M_get_deleter(const std::type_info&) = 0;
+
+ void
+ _M_add_ref_copy()
+ { __gnu_cxx::__atomic_add_dispatch(&_M_use_count, 1); }
+
+ void
+ _M_add_ref_lock();
+
+ void
+ _M_release() noexcept
+ {
+ // Be race-detector-friendly. For more info see bits/c++config.
+ _GLIBCXX_SYNCHRONIZATION_HAPPENS_BEFORE(&_M_use_count);
+ if (__gnu_cxx::__exchange_and_add_dispatch(&_M_use_count, -1) == 1)
+ {
+ _GLIBCXX_SYNCHRONIZATION_HAPPENS_AFTER(&_M_use_count);
+ _M_dispose();
+ // There must be a memory barrier between dispose() and destroy()
+ // to ensure that the effects of dispose() are observed in the
+ // thread that runs destroy().
+ // See http://gcc.gnu.org/ml/libstdc++/2005-11/msg00136.html
+ if (_Mutex_base<_Lp>::_S_need_barriers)
+ {
+ _GLIBCXX_READ_MEM_BARRIER;
+ _GLIBCXX_WRITE_MEM_BARRIER;
+ }
+
+ // Be race-detector-friendly. For more info see bits/c++config.
+ _GLIBCXX_SYNCHRONIZATION_HAPPENS_BEFORE(&_M_weak_count);
+ if (__gnu_cxx::__exchange_and_add_dispatch(&_M_weak_count,
+ -1) == 1)
+ {
+ _GLIBCXX_SYNCHRONIZATION_HAPPENS_AFTER(&_M_weak_count);
+ _M_destroy();
+ }
+ }
+ }
+
+ void
+ _M_weak_add_ref() noexcept
+ { __gnu_cxx::__atomic_add_dispatch(&_M_weak_count, 1); }
+
+ void
+ _M_weak_release() noexcept
+ {
+ // Be race-detector-friendly. For more info see bits/c++config.
+ _GLIBCXX_SYNCHRONIZATION_HAPPENS_BEFORE(&_M_weak_count);
+ if (__gnu_cxx::__exchange_and_add_dispatch(&_M_weak_count, -1) == 1)
+ {
+ _GLIBCXX_SYNCHRONIZATION_HAPPENS_AFTER(&_M_weak_count);
+ if (_Mutex_base<_Lp>::_S_need_barriers)
+ {
+ // See _M_release(),
+ // destroy() must observe results of dispose()
+ _GLIBCXX_READ_MEM_BARRIER;
+ _GLIBCXX_WRITE_MEM_BARRIER;
+ }
+ _M_destroy();
+ }
+ }
+
+ long
+ _M_get_use_count() const noexcept
+ {
+ // No memory barrier is used here so there is no synchronization
+ // with other threads.
+ return __atomic_load_n(&_M_use_count, __ATOMIC_RELAXED);
+ }
+
+ private:
+ _Sp_counted_base(_Sp_counted_base const&) = delete;
+ _Sp_counted_base& operator=(_Sp_counted_base const&) = delete;
+
+ _Atomic_word _M_use_count; // #shared
+ _Atomic_word _M_weak_count; // #weak + (#shared != 0)
+ };
+
+ template<>
+ inline void
+ _Sp_counted_base<_S_single>::
+ _M_add_ref_lock()
+ {
+ if (__gnu_cxx::__exchange_and_add_dispatch(&_M_use_count, 1) == 0)
+ {
+ _M_use_count = 0;
+ __throw_bad_weak_ptr();
+ }
+ }
+
+ template<>
+ inline void
+ _Sp_counted_base<_S_mutex>::
+ _M_add_ref_lock()
+ {
+ __gnu_cxx::__scoped_lock sentry(*this);
+ if (__gnu_cxx::__exchange_and_add_dispatch(&_M_use_count, 1) == 0)
+ {
+ _M_use_count = 0;
+ __throw_bad_weak_ptr();
+ }
+ }
+
+ template<>
+ inline void
+ _Sp_counted_base<_S_atomic>::
+ _M_add_ref_lock()
+ {
+ // Perform lock-free add-if-not-zero operation.
+ _Atomic_word __count = _M_use_count;
+ do
+ {
+ if (__count == 0)
+ __throw_bad_weak_ptr();
+ // Replace the current counter value with the old value + 1, as
+ // long as it's not changed meanwhile.
+ }
+ while (!__atomic_compare_exchange_n(&_M_use_count, &__count, __count + 1,
+ true, __ATOMIC_ACQ_REL,
+ __ATOMIC_RELAXED));
+ }
+
+
+ // Forward declarations.
+ template<typename _Tp, _Lock_policy _Lp = __default_lock_policy>
+ class __shared_ptr;
+
+ template<typename _Tp, _Lock_policy _Lp = __default_lock_policy>
+ class __weak_ptr;
+
+ template<typename _Tp, _Lock_policy _Lp = __default_lock_policy>
+ class __enable_shared_from_this;
+
+ template<typename _Tp>
+ class shared_ptr;
+
+ template<typename _Tp>
+ class weak_ptr;
+
+ template<typename _Tp>
+ struct owner_less;
+
+ template<typename _Tp>
+ class enable_shared_from_this;
+
+ template<_Lock_policy _Lp = __default_lock_policy>
+ class __weak_count;
+
+ template<_Lock_policy _Lp = __default_lock_policy>
+ class __shared_count;
+
+
+ // Counted ptr with no deleter or allocator support
+ template<typename _Ptr, _Lock_policy _Lp>
+ class _Sp_counted_ptr final : public _Sp_counted_base<_Lp>
+ {
+ public:
+ explicit
+ _Sp_counted_ptr(_Ptr __p)
+ : _M_ptr(__p) { }
+
+ virtual void
+ _M_dispose() noexcept
+ { delete _M_ptr; }
+
+ virtual void
+ _M_destroy() noexcept
+ { delete this; }
+
+ virtual void*
+ _M_get_deleter(const std::type_info&)
+ { return 0; }
+
+ _Sp_counted_ptr(const _Sp_counted_ptr&) = delete;
+ _Sp_counted_ptr& operator=(const _Sp_counted_ptr&) = delete;
+
+ protected:
+ _Ptr _M_ptr; // copy constructor must not throw
+ };
+
+ template<>
+ inline void
+ _Sp_counted_ptr<nullptr_t, _S_single>::_M_dispose() noexcept { }
+
+ template<>
+ inline void
+ _Sp_counted_ptr<nullptr_t, _S_mutex>::_M_dispose() noexcept { }
+
+ template<>
+ inline void
+ _Sp_counted_ptr<nullptr_t, _S_atomic>::_M_dispose() noexcept { }
+
+ // Support for custom deleter and/or allocator
+ template<typename _Ptr, typename _Deleter, typename _Alloc, _Lock_policy _Lp>
+ class _Sp_counted_deleter final : public _Sp_counted_base<_Lp>
+ {
+ // Helper class that stores the Deleter and also acts as an allocator.
+ // Used to dispose of the owned pointer and the internal refcount
+ // Requires that copies of _Alloc can free each other's memory.
+ struct _My_Deleter
+ : public _Alloc // copy constructor must not throw
+ {
+ _Deleter _M_del; // copy constructor must not throw
+ _My_Deleter(_Deleter __d, const _Alloc& __a)
+ : _Alloc(__a), _M_del(__d) { }
+ };
+
+ public:
+ // __d(__p) must not throw.
+ _Sp_counted_deleter(_Ptr __p, _Deleter __d)
+ : _M_ptr(__p), _M_del(__d, _Alloc()) { }
+
+ // __d(__p) must not throw.
+ _Sp_counted_deleter(_Ptr __p, _Deleter __d, const _Alloc& __a)
+ : _M_ptr(__p), _M_del(__d, __a) { }
+
+ ~_Sp_counted_deleter() noexcept { }
+
+ virtual void
+ _M_dispose() noexcept
+ { _M_del._M_del(_M_ptr); }
+
+ virtual void
+ _M_destroy() noexcept
+ {
+ typedef typename allocator_traits<_Alloc>::template
+ rebind_traits<_Sp_counted_deleter> _Alloc_traits;
+ typename _Alloc_traits::allocator_type __a(_M_del);
+ _Alloc_traits::destroy(__a, this);
+ _Alloc_traits::deallocate(__a, this, 1);
+ }
+
+ virtual void*
+ _M_get_deleter(const std::type_info& __ti)
+ {
+#ifdef __GXX_RTTI
+ return __ti == typeid(_Deleter) ? &_M_del._M_del : 0;
+#else
+ return 0;
+#endif
+ }
+
+ protected:
+ _Ptr _M_ptr; // copy constructor must not throw
+ _My_Deleter _M_del; // copy constructor must not throw
+ };
+
+ // helpers for make_shared / allocate_shared
+
+ struct _Sp_make_shared_tag { };
+
+ template<typename _Tp, typename _Alloc, _Lock_policy _Lp>
+ class _Sp_counted_ptr_inplace final : public _Sp_counted_base<_Lp>
+ {
+ // Helper class that stores the pointer and also acts as an allocator.
+ // Used to dispose of the owned pointer and the internal refcount
+ // Requires that copies of _Alloc can free each other's memory.
+ struct _Impl
+ : public _Alloc // copy constructor must not throw
+ {
+ _Impl(_Alloc __a) : _Alloc(__a), _M_ptr() { }
+ _Tp* _M_ptr;
+ };
+
+ public:
+ template<typename... _Args>
+ _Sp_counted_ptr_inplace(_Alloc __a, _Args&&... __args)
+ : _M_impl(__a)
+ {
+ _M_impl._M_ptr = static_cast<_Tp*>(static_cast<void*>(&_M_storage));
+ // _GLIBCXX_RESOLVE_LIB_DEFECTS
+ // 2070. allocate_shared should use allocator_traits<A>::construct
+ allocator_traits<_Alloc>::construct(__a, _M_impl._M_ptr,
+ std::forward<_Args>(__args)...); // might throw
+ }
+
+ ~_Sp_counted_ptr_inplace() noexcept { }
+
+ virtual void
+ _M_dispose() noexcept
+ { allocator_traits<_Alloc>::destroy(_M_impl, _M_impl._M_ptr); }
+
+ // Override because the allocator needs to know the dynamic type
+ virtual void
+ _M_destroy() noexcept
+ {
+ typedef typename allocator_traits<_Alloc>::template
+ rebind_traits<_Sp_counted_ptr_inplace> _Alloc_traits;
+ typename _Alloc_traits::allocator_type __a(_M_impl);
+ _Alloc_traits::destroy(__a, this);
+ _Alloc_traits::deallocate(__a, this, 1);
+ }
+
+ // Sneaky trick so __shared_ptr can get the managed pointer
+ virtual void*
+ _M_get_deleter(const std::type_info& __ti) noexcept
+ {
+#ifdef __GXX_RTTI
+ return __ti == typeid(_Sp_make_shared_tag)
+ ? static_cast<void*>(&_M_storage)
+ : 0;
+#else
+ return 0;
+#endif
+ }
+
+ private:
+ _Impl _M_impl;
+ typename aligned_storage<sizeof(_Tp), alignment_of<_Tp>::value>::type
+ _M_storage;
+ };
+
+ template<_Lock_policy _Lp>
+ class __shared_count
+ {
+ public:
+ constexpr __shared_count() noexcept : _M_pi(0)
+ { }
+
+ template<typename _Ptr>
+ explicit
+ __shared_count(_Ptr __p) : _M_pi(0)
+ {
+ __try
+ {
+ _M_pi = new _Sp_counted_ptr<_Ptr, _Lp>(__p);
+ }
+ __catch(...)
+ {
+ delete __p;
+ __throw_exception_again;
+ }
+ }
+
+ template<typename _Ptr, typename _Deleter>
+ __shared_count(_Ptr __p, _Deleter __d) : _M_pi(0)
+ {
+ // The allocator's value_type doesn't matter, will rebind it anyway.
+ typedef std::allocator<int> _Alloc;
+ typedef _Sp_counted_deleter<_Ptr, _Deleter, _Alloc, _Lp> _Sp_cd_type;
+ typedef typename allocator_traits<_Alloc>::template
+ rebind_traits<_Sp_cd_type> _Alloc_traits;
+ typename _Alloc_traits::allocator_type __a;
+ _Sp_cd_type* __mem = 0;
+ __try
+ {
+ __mem = _Alloc_traits::allocate(__a, 1);
+ _Alloc_traits::construct(__a, __mem, __p, std::move(__d));
+ _M_pi = __mem;
+ }
+ __catch(...)
+ {
+ __d(__p); // Call _Deleter on __p.
+ if (__mem)
+ _Alloc_traits::deallocate(__a, __mem, 1);
+ __throw_exception_again;
+ }
+ }
+
+ template<typename _Ptr, typename _Deleter, typename _Alloc>
+ __shared_count(_Ptr __p, _Deleter __d, _Alloc __a) : _M_pi(0)
+ {
+ typedef _Sp_counted_deleter<_Ptr, _Deleter, _Alloc, _Lp> _Sp_cd_type;
+ typedef typename allocator_traits<_Alloc>::template
+ rebind_traits<_Sp_cd_type> _Alloc_traits;
+ typename _Alloc_traits::allocator_type __a2(__a);
+ _Sp_cd_type* __mem = 0;
+ __try
+ {
+ __mem = _Alloc_traits::allocate(__a2, 1);
+ _Alloc_traits::construct(__a2, __mem,
+ __p, std::move(__d), std::move(__a));
+ _M_pi = __mem;
+ }
+ __catch(...)
+ {
+ __d(__p); // Call _Deleter on __p.
+ if (__mem)
+ _Alloc_traits::deallocate(__a2, __mem, 1);
+ __throw_exception_again;
+ }
+ }
+
+ template<typename _Tp, typename _Alloc, typename... _Args>
+ __shared_count(_Sp_make_shared_tag, _Tp*, const _Alloc& __a,
+ _Args&&... __args)
+ : _M_pi(0)
+ {
+ typedef _Sp_counted_ptr_inplace<_Tp, _Alloc, _Lp> _Sp_cp_type;
+ typedef typename allocator_traits<_Alloc>::template
+ rebind_traits<_Sp_cp_type> _Alloc_traits;
+ typename _Alloc_traits::allocator_type __a2(__a);
+ _Sp_cp_type* __mem = _Alloc_traits::allocate(__a2, 1);
+ __try
+ {
+ _Alloc_traits::construct(__a2, __mem, std::move(__a),
+ std::forward<_Args>(__args)...);
+ _M_pi = __mem;
+ }
+ __catch(...)
+ {
+ _Alloc_traits::deallocate(__a2, __mem, 1);
+ __throw_exception_again;
+ }
+ }
+
+#if _GLIBCXX_USE_DEPRECATED
+ // Special case for auto_ptr<_Tp> to provide the strong guarantee.
+ template<typename _Tp>
+ explicit
+ __shared_count(std::auto_ptr<_Tp>&& __r)
+ : _M_pi(new _Sp_counted_ptr<_Tp*, _Lp>(__r.get()))
+ { __r.release(); }
+#endif
+
+ // Special case for unique_ptr<_Tp,_Del> to provide the strong guarantee.
+ template<typename _Tp, typename _Del>
+ explicit
+ __shared_count(std::unique_ptr<_Tp, _Del>&& __r)
+ : _M_pi(_S_create_from_up(std::move(__r)))
+ { __r.release(); }
+
+ // Throw bad_weak_ptr when __r._M_get_use_count() == 0.
+ explicit __shared_count(const __weak_count<_Lp>& __r);
+
+ ~__shared_count() noexcept
+ {
+ if (_M_pi != 0)
+ _M_pi->_M_release();
+ }
+
+ __shared_count(const __shared_count& __r) noexcept
+ : _M_pi(__r._M_pi)
+ {
+ if (_M_pi != 0)
+ _M_pi->_M_add_ref_copy();
+ }
+
+ __shared_count&
+ operator=(const __shared_count& __r) noexcept
+ {
+ _Sp_counted_base<_Lp>* __tmp = __r._M_pi;
+ if (__tmp != _M_pi)
+ {
+ if (__tmp != 0)
+ __tmp->_M_add_ref_copy();
+ if (_M_pi != 0)
+ _M_pi->_M_release();
+ _M_pi = __tmp;
+ }
+ return *this;
+ }
+
+ void
+ _M_swap(__shared_count& __r) noexcept
+ {
+ _Sp_counted_base<_Lp>* __tmp = __r._M_pi;
+ __r._M_pi = _M_pi;
+ _M_pi = __tmp;
+ }
+
+ long
+ _M_get_use_count() const noexcept
+ { return _M_pi != 0 ? _M_pi->_M_get_use_count() : 0; }
+
+ bool
+ _M_unique() const noexcept
+ { return this->_M_get_use_count() == 1; }
+
+ void*
+ _M_get_deleter(const std::type_info& __ti) const noexcept
+ { return _M_pi ? _M_pi->_M_get_deleter(__ti) : 0; }
+
+ bool
+ _M_less(const __shared_count& __rhs) const noexcept
+ { return std::less<_Sp_counted_base<_Lp>*>()(this->_M_pi, __rhs._M_pi); }
+
+ bool
+ _M_less(const __weak_count<_Lp>& __rhs) const noexcept
+ { return std::less<_Sp_counted_base<_Lp>*>()(this->_M_pi, __rhs._M_pi); }
+
+ // Friend function injected into enclosing namespace and found by ADL
+ friend inline bool
+ operator==(const __shared_count& __a, const __shared_count& __b) noexcept
+ { return __a._M_pi == __b._M_pi; }
+
+ private:
+ friend class __weak_count<_Lp>;
+
+ template<typename _Tp, typename _Del>
+ static _Sp_counted_base<_Lp>*
+ _S_create_from_up(std::unique_ptr<_Tp, _Del>&& __r,
+ typename std::enable_if<!std::is_reference<_Del>::value>::type* = 0)
+ {
+ return new _Sp_counted_deleter<_Tp*, _Del, std::allocator<void>,
+ _Lp>(__r.get(), __r.get_deleter());
+ }
+
+ template<typename _Tp, typename _Del>
+ static _Sp_counted_base<_Lp>*
+ _S_create_from_up(std::unique_ptr<_Tp, _Del>&& __r,
+ typename std::enable_if<std::is_reference<_Del>::value>::type* = 0)
+ {
+ typedef typename std::remove_reference<_Del>::type _Del1;
+ typedef std::reference_wrapper<_Del1> _Del2;
+ return new _Sp_counted_deleter<_Tp*, _Del2, std::allocator<void>,
+ _Lp>(__r.get(), std::ref(__r.get_deleter()));
+ }
+
+ _Sp_counted_base<_Lp>* _M_pi;
+ };
+
+
+ template<_Lock_policy _Lp>
+ class __weak_count
+ {
+ public:
+ constexpr __weak_count() noexcept : _M_pi(0)
+ { }
+
+ __weak_count(const __shared_count<_Lp>& __r) noexcept
+ : _M_pi(__r._M_pi)
+ {
+ if (_M_pi != 0)
+ _M_pi->_M_weak_add_ref();
+ }
+
+ __weak_count(const __weak_count<_Lp>& __r) noexcept
+ : _M_pi(__r._M_pi)
+ {
+ if (_M_pi != 0)
+ _M_pi->_M_weak_add_ref();
+ }
+
+ ~__weak_count() noexcept
+ {
+ if (_M_pi != 0)
+ _M_pi->_M_weak_release();
+ }
+
+ __weak_count<_Lp>&
+ operator=(const __shared_count<_Lp>& __r) noexcept
+ {
+ _Sp_counted_base<_Lp>* __tmp = __r._M_pi;
+ if (__tmp != 0)
+ __tmp->_M_weak_add_ref();
+ if (_M_pi != 0)
+ _M_pi->_M_weak_release();
+ _M_pi = __tmp;
+ return *this;
+ }
+
+ __weak_count<_Lp>&
+ operator=(const __weak_count<_Lp>& __r) noexcept
+ {
+ _Sp_counted_base<_Lp>* __tmp = __r._M_pi;
+ if (__tmp != 0)
+ __tmp->_M_weak_add_ref();
+ if (_M_pi != 0)
+ _M_pi->_M_weak_release();
+ _M_pi = __tmp;
+ return *this;
+ }
+
+ void
+ _M_swap(__weak_count<_Lp>& __r) noexcept
+ {
+ _Sp_counted_base<_Lp>* __tmp = __r._M_pi;
+ __r._M_pi = _M_pi;
+ _M_pi = __tmp;
+ }
+
+ long
+ _M_get_use_count() const noexcept
+ { return _M_pi != 0 ? _M_pi->_M_get_use_count() : 0; }
+
+ bool
+ _M_less(const __weak_count& __rhs) const noexcept
+ { return std::less<_Sp_counted_base<_Lp>*>()(this->_M_pi, __rhs._M_pi); }
+
+ bool
+ _M_less(const __shared_count<_Lp>& __rhs) const noexcept
+ { return std::less<_Sp_counted_base<_Lp>*>()(this->_M_pi, __rhs._M_pi); }
+
+ // Friend function injected into enclosing namespace and found by ADL
+ friend inline bool
+ operator==(const __weak_count& __a, const __weak_count& __b) noexcept
+ { return __a._M_pi == __b._M_pi; }
+
+ private:
+ friend class __shared_count<_Lp>;
+
+ _Sp_counted_base<_Lp>* _M_pi;
+ };
+
+ // Now that __weak_count is defined we can define this constructor:
+ template<_Lock_policy _Lp>
+ inline __shared_count<_Lp>:: __shared_count(const __weak_count<_Lp>& __r)
+ : _M_pi(__r._M_pi)
+ {
+ if (_M_pi != 0)
+ _M_pi->_M_add_ref_lock();
+ else
+ __throw_bad_weak_ptr();
+ }
+
+
+ // Support for enable_shared_from_this.
+
+ // Friend of __enable_shared_from_this.
+ template<_Lock_policy _Lp, typename _Tp1, typename _Tp2>
+ void
+ __enable_shared_from_this_helper(const __shared_count<_Lp>&,
+ const __enable_shared_from_this<_Tp1,
+ _Lp>*, const _Tp2*) noexcept;
+
+ // Friend of enable_shared_from_this.
+ template<typename _Tp1, typename _Tp2>
+ void
+ __enable_shared_from_this_helper(const __shared_count<>&,
+ const enable_shared_from_this<_Tp1>*,
+ const _Tp2*) noexcept;
+
+ template<_Lock_policy _Lp>
+ inline void
+ __enable_shared_from_this_helper(const __shared_count<_Lp>&, ...) noexcept
+ { }
+
+
+ template<typename _Tp, _Lock_policy _Lp>
+ class __shared_ptr
+ {
+ public:
+ typedef _Tp element_type;
+
+ constexpr __shared_ptr() noexcept
+ : _M_ptr(0), _M_refcount()
+ { }
+
+ template<typename _Tp1>
+ explicit __shared_ptr(_Tp1* __p)
+ : _M_ptr(__p), _M_refcount(__p)
+ {
+ __glibcxx_function_requires(_ConvertibleConcept<_Tp1*, _Tp*>)
+ static_assert( sizeof(_Tp1) > 0, "incomplete type" );
+ __enable_shared_from_this_helper(_M_refcount, __p, __p);
+ }
+
+ template<typename _Tp1, typename _Deleter>
+ __shared_ptr(_Tp1* __p, _Deleter __d)
+ : _M_ptr(__p), _M_refcount(__p, __d)
+ {
+ __glibcxx_function_requires(_ConvertibleConcept<_Tp1*, _Tp*>)
+ // TODO requires _Deleter CopyConstructible and __d(__p) well-formed
+ __enable_shared_from_this_helper(_M_refcount, __p, __p);
+ }
+
+ template<typename _Tp1, typename _Deleter, typename _Alloc>
+ __shared_ptr(_Tp1* __p, _Deleter __d, _Alloc __a)
+ : _M_ptr(__p), _M_refcount(__p, __d, std::move(__a))
+ {
+ __glibcxx_function_requires(_ConvertibleConcept<_Tp1*, _Tp*>)
+ // TODO requires _Deleter CopyConstructible and __d(__p) well-formed
+ __enable_shared_from_this_helper(_M_refcount, __p, __p);
+ }
+
+ template<typename _Deleter>
+ __shared_ptr(nullptr_t __p, _Deleter __d)
+ : _M_ptr(0), _M_refcount(__p, __d)
+ { }
+
+ template<typename _Deleter, typename _Alloc>
+ __shared_ptr(nullptr_t __p, _Deleter __d, _Alloc __a)
+ : _M_ptr(0), _M_refcount(__p, __d, std::move(__a))
+ { }
+
+ template<typename _Tp1>
+ __shared_ptr(const __shared_ptr<_Tp1, _Lp>& __r, _Tp* __p) noexcept
+ : _M_ptr(__p), _M_refcount(__r._M_refcount) // never throws
+ { }
+
+ __shared_ptr(const __shared_ptr&) noexcept = default;
+ __shared_ptr& operator=(const __shared_ptr&) noexcept = default;
+ ~__shared_ptr() = default;
+
+ template<typename _Tp1, typename = typename
+ std::enable_if<std::is_convertible<_Tp1*, _Tp*>::value>::type>
+ __shared_ptr(const __shared_ptr<_Tp1, _Lp>& __r) noexcept
+ : _M_ptr(__r._M_ptr), _M_refcount(__r._M_refcount)
+ { }
+
+ __shared_ptr(__shared_ptr&& __r) noexcept
+ : _M_ptr(__r._M_ptr), _M_refcount()
+ {
+ _M_refcount._M_swap(__r._M_refcount);
+ __r._M_ptr = 0;
+ }
+
+ template<typename _Tp1, typename = typename
+ std::enable_if<std::is_convertible<_Tp1*, _Tp*>::value>::type>
+ __shared_ptr(__shared_ptr<_Tp1, _Lp>&& __r) noexcept
+ : _M_ptr(__r._M_ptr), _M_refcount()
+ {
+ _M_refcount._M_swap(__r._M_refcount);
+ __r._M_ptr = 0;
+ }
+
+ template<typename _Tp1>
+ explicit __shared_ptr(const __weak_ptr<_Tp1, _Lp>& __r)
+ : _M_refcount(__r._M_refcount) // may throw
+ {
+ __glibcxx_function_requires(_ConvertibleConcept<_Tp1*, _Tp*>)
+
+ // It is now safe to copy __r._M_ptr, as
+ // _M_refcount(__r._M_refcount) did not throw.
+ _M_ptr = __r._M_ptr;
+ }
+
+ // If an exception is thrown this constructor has no effect.
+ template<typename _Tp1, typename _Del>
+ __shared_ptr(std::unique_ptr<_Tp1, _Del>&& __r)
+ : _M_ptr(__r.get()), _M_refcount()
+ {
+ __glibcxx_function_requires(_ConvertibleConcept<_Tp1*, _Tp*>)
+ _Tp1* __tmp = __r.get();
+ _M_refcount = __shared_count<_Lp>(std::move(__r));
+ __enable_shared_from_this_helper(_M_refcount, __tmp, __tmp);
+ }
+
+#if _GLIBCXX_USE_DEPRECATED
+ // Postcondition: use_count() == 1 and __r.get() == 0
+ template<typename _Tp1>
+ __shared_ptr(std::auto_ptr<_Tp1>&& __r)
+ : _M_ptr(__r.get()), _M_refcount()
+ {
+ __glibcxx_function_requires(_ConvertibleConcept<_Tp1*, _Tp*>)
+ static_assert( sizeof(_Tp1) > 0, "incomplete type" );
+ _Tp1* __tmp = __r.get();
+ _M_refcount = __shared_count<_Lp>(std::move(__r));
+ __enable_shared_from_this_helper(_M_refcount, __tmp, __tmp);
+ }
+#endif
+
+ /* TODO: use delegating constructor */
+ constexpr __shared_ptr(nullptr_t) noexcept
+ : _M_ptr(0), _M_refcount()
+ { }
+
+ template<typename _Tp1>
+ __shared_ptr&
+ operator=(const __shared_ptr<_Tp1, _Lp>& __r) noexcept
+ {
+ _M_ptr = __r._M_ptr;
+ _M_refcount = __r._M_refcount; // __shared_count::op= doesn't throw
+ return *this;
+ }
+
+#if _GLIBCXX_USE_DEPRECATED
+ template<typename _Tp1>
+ __shared_ptr&
+ operator=(std::auto_ptr<_Tp1>&& __r)
+ {
+ __shared_ptr(std::move(__r)).swap(*this);
+ return *this;
+ }
+#endif
+
+ __shared_ptr&
+ operator=(__shared_ptr&& __r) noexcept
+ {
+ __shared_ptr(std::move(__r)).swap(*this);
+ return *this;
+ }
+
+ template<class _Tp1>
+ __shared_ptr&
+ operator=(__shared_ptr<_Tp1, _Lp>&& __r) noexcept
+ {
+ __shared_ptr(std::move(__r)).swap(*this);
+ return *this;
+ }
+
+ template<typename _Tp1, typename _Del>
+ __shared_ptr&
+ operator=(std::unique_ptr<_Tp1, _Del>&& __r)
+ {
+ __shared_ptr(std::move(__r)).swap(*this);
+ return *this;
+ }
+
+ void
+ reset() noexcept
+ { __shared_ptr().swap(*this); }
+
+ template<typename _Tp1>
+ void
+ reset(_Tp1* __p) // _Tp1 must be complete.
+ {
+ // Catch self-reset errors.
+ _GLIBCXX_DEBUG_ASSERT(__p == 0 || __p != _M_ptr);
+ __shared_ptr(__p).swap(*this);
+ }
+
+ template<typename _Tp1, typename _Deleter>
+ void
+ reset(_Tp1* __p, _Deleter __d)
+ { __shared_ptr(__p, __d).swap(*this); }
+
+ template<typename _Tp1, typename _Deleter, typename _Alloc>
+ void
+ reset(_Tp1* __p, _Deleter __d, _Alloc __a)
+ { __shared_ptr(__p, __d, std::move(__a)).swap(*this); }
+
+ // Allow class instantiation when _Tp is [cv-qual] void.
+ typename std::add_lvalue_reference<_Tp>::type
+ operator*() const noexcept
+ {
+ _GLIBCXX_DEBUG_ASSERT(_M_ptr != 0);
+ return *_M_ptr;
+ }
+
+ _Tp*
+ operator->() const noexcept
+ {
+ _GLIBCXX_DEBUG_ASSERT(_M_ptr != 0);
+ return _M_ptr;
+ }
+
+ _Tp*
+ get() const noexcept
+ { return _M_ptr; }
+
+ explicit operator bool() const // never throws
+ { return _M_ptr == 0 ? false : true; }
+
+ bool
+ unique() const noexcept
+ { return _M_refcount._M_unique(); }
+
+ long
+ use_count() const noexcept
+ { return _M_refcount._M_get_use_count(); }
+
+ void
+ swap(__shared_ptr<_Tp, _Lp>& __other) noexcept
+ {
+ std::swap(_M_ptr, __other._M_ptr);
+ _M_refcount._M_swap(__other._M_refcount);
+ }
+
+ template<typename _Tp1>
+ bool
+ owner_before(__shared_ptr<_Tp1, _Lp> const& __rhs) const
+ { return _M_refcount._M_less(__rhs._M_refcount); }
+
+ template<typename _Tp1>
+ bool
+ owner_before(__weak_ptr<_Tp1, _Lp> const& __rhs) const
+ { return _M_refcount._M_less(__rhs._M_refcount); }
+
+#ifdef __GXX_RTTI
+ protected:
+ // This constructor is non-standard, it is used by allocate_shared.
+ template<typename _Alloc, typename... _Args>
+ __shared_ptr(_Sp_make_shared_tag __tag, const _Alloc& __a,
+ _Args&&... __args)
+ : _M_ptr(), _M_refcount(__tag, (_Tp*)0, __a,
+ std::forward<_Args>(__args)...)
+ {
+ // _M_ptr needs to point to the newly constructed object.
+ // This relies on _Sp_counted_ptr_inplace::_M_get_deleter.
+ void* __p = _M_refcount._M_get_deleter(typeid(__tag));
+ _M_ptr = static_cast<_Tp*>(__p);
+ __enable_shared_from_this_helper(_M_refcount, _M_ptr, _M_ptr);
+ }
+#else
+ template<typename _Alloc>
+ struct _Deleter
+ {
+ void operator()(_Tp* __ptr)
+ {
+ typedef allocator_traits<_Alloc> _Alloc_traits;
+ _Alloc_traits::destroy(_M_alloc, __ptr);
+ _Alloc_traits::deallocate(_M_alloc, __ptr, 1);
+ }
+ _Alloc _M_alloc;
+ };
+
+ template<typename _Alloc, typename... _Args>
+ __shared_ptr(_Sp_make_shared_tag __tag, const _Alloc& __a,
+ _Args&&... __args)
+ : _M_ptr(), _M_refcount()
+ {
+ typedef typename _Alloc::template rebind<_Tp>::other _Alloc2;
+ _Deleter<_Alloc2> __del = { _Alloc2(__a) };
+ typedef allocator_traits<_Alloc2> __traits;
+ _M_ptr = __traits::allocate(__del._M_alloc, 1);
+ __try
+ {
+ // _GLIBCXX_RESOLVE_LIB_DEFECTS
+ // 2070. allocate_shared should use allocator_traits<A>::construct
+ __traits::construct(__del._M_alloc, _M_ptr,
+ std::forward<_Args>(__args)...);
+ }
+ __catch(...)
+ {
+ __traits::deallocate(__del._M_alloc, _M_ptr, 1);
+ __throw_exception_again;
+ }
+ __shared_count<_Lp> __count(_M_ptr, __del, __del._M_alloc);
+ _M_refcount._M_swap(__count);
+ __enable_shared_from_this_helper(_M_refcount, _M_ptr, _M_ptr);
+ }
+#endif
+
+ template<typename _Tp1, _Lock_policy _Lp1, typename _Alloc,
+ typename... _Args>
+ friend __shared_ptr<_Tp1, _Lp1>
+ __allocate_shared(const _Alloc& __a, _Args&&... __args);
+
+ private:
+ void*
+ _M_get_deleter(const std::type_info& __ti) const noexcept
+ { return _M_refcount._M_get_deleter(__ti); }
+
+ template<typename _Tp1, _Lock_policy _Lp1> friend class __shared_ptr;
+ template<typename _Tp1, _Lock_policy _Lp1> friend class __weak_ptr;
+
+ template<typename _Del, typename _Tp1, _Lock_policy _Lp1>
+ friend _Del* get_deleter(const __shared_ptr<_Tp1, _Lp1>&) noexcept;
+
+ _Tp* _M_ptr; // Contained pointer.
+ __shared_count<_Lp> _M_refcount; // Reference counter.
+ };
+
+
+ // 20.8.13.2.7 shared_ptr comparisons
+ template<typename _Tp1, typename _Tp2, _Lock_policy _Lp>
+ inline bool
+ operator==(const __shared_ptr<_Tp1, _Lp>& __a,
+ const __shared_ptr<_Tp2, _Lp>& __b) noexcept
+ { return __a.get() == __b.get(); }
+
+ template<typename _Tp, _Lock_policy _Lp>
+ inline bool
+ operator==(const __shared_ptr<_Tp, _Lp>& __a, nullptr_t) noexcept
+ { return !__a; }
+
+ template<typename _Tp, _Lock_policy _Lp>
+ inline bool
+ operator==(nullptr_t, const __shared_ptr<_Tp, _Lp>& __a) noexcept
+ { return !__a; }
+
+ template<typename _Tp1, typename _Tp2, _Lock_policy _Lp>
+ inline bool
+ operator!=(const __shared_ptr<_Tp1, _Lp>& __a,
+ const __shared_ptr<_Tp2, _Lp>& __b) noexcept
+ { return __a.get() != __b.get(); }
+
+ template<typename _Tp, _Lock_policy _Lp>
+ inline bool
+ operator!=(const __shared_ptr<_Tp, _Lp>& __a, nullptr_t) noexcept
+ { return (bool)__a; }
+
+ template<typename _Tp, _Lock_policy _Lp>
+ inline bool
+ operator!=(nullptr_t, const __shared_ptr<_Tp, _Lp>& __a) noexcept
+ { return (bool)__a; }
+
+ template<typename _Tp1, typename _Tp2, _Lock_policy _Lp>
+ inline bool
+ operator<(const __shared_ptr<_Tp1, _Lp>& __a,
+ const __shared_ptr<_Tp2, _Lp>& __b) noexcept
+ {
+ typedef typename std::common_type<_Tp1*, _Tp2*>::type _CT;
+ return std::less<_CT>()(__a.get(), __b.get());
+ }
+
+ template<typename _Tp, _Lock_policy _Lp>
+ inline bool
+ operator<(const __shared_ptr<_Tp, _Lp>& __a, nullptr_t) noexcept
+ { return std::less<_Tp*>()(__a.get(), nullptr); }
+
+ template<typename _Tp, _Lock_policy _Lp>
+ inline bool
+ operator<(nullptr_t, const __shared_ptr<_Tp, _Lp>& __a) noexcept
+ { return std::less<_Tp*>()(nullptr, __a.get()); }
+
+ template<typename _Tp1, typename _Tp2, _Lock_policy _Lp>
+ inline bool
+ operator<=(const __shared_ptr<_Tp1, _Lp>& __a,
+ const __shared_ptr<_Tp2, _Lp>& __b) noexcept
+ { return !(__b < __a); }
+
+ template<typename _Tp, _Lock_policy _Lp>
+ inline bool
+ operator<=(const __shared_ptr<_Tp, _Lp>& __a, nullptr_t) noexcept
+ { return !(nullptr < __a); }
+
+ template<typename _Tp, _Lock_policy _Lp>
+ inline bool
+ operator<=(nullptr_t, const __shared_ptr<_Tp, _Lp>& __a) noexcept
+ { return !(__a < nullptr); }
+
+ template<typename _Tp1, typename _Tp2, _Lock_policy _Lp>
+ inline bool
+ operator>(const __shared_ptr<_Tp1, _Lp>& __a,
+ const __shared_ptr<_Tp2, _Lp>& __b) noexcept
+ { return (__b < __a); }
+
+ template<typename _Tp, _Lock_policy _Lp>
+ inline bool
+ operator>(const __shared_ptr<_Tp, _Lp>& __a, nullptr_t) noexcept
+ { return std::less<_Tp*>()(nullptr, __a.get()); }
+
+ template<typename _Tp, _Lock_policy _Lp>
+ inline bool
+ operator>(nullptr_t, const __shared_ptr<_Tp, _Lp>& __a) noexcept
+ { return std::less<_Tp*>()(__a.get(), nullptr); }
+
+ template<typename _Tp1, typename _Tp2, _Lock_policy _Lp>
+ inline bool
+ operator>=(const __shared_ptr<_Tp1, _Lp>& __a,
+ const __shared_ptr<_Tp2, _Lp>& __b) noexcept
+ { return !(__a < __b); }
+
+ template<typename _Tp, _Lock_policy _Lp>
+ inline bool
+ operator>=(const __shared_ptr<_Tp, _Lp>& __a, nullptr_t) noexcept
+ { return !(__a < nullptr); }
+
+ template<typename _Tp, _Lock_policy _Lp>
+ inline bool
+ operator>=(nullptr_t, const __shared_ptr<_Tp, _Lp>& __a) noexcept
+ { return !(nullptr < __a); }
+
+ template<typename _Sp>
+ struct _Sp_less : public binary_function<_Sp, _Sp, bool>
+ {
+ bool
+ operator()(const _Sp& __lhs, const _Sp& __rhs) const noexcept
+ {
+ typedef typename _Sp::element_type element_type;
+ return std::less<element_type*>()(__lhs.get(), __rhs.get());
+ }
+ };
+
+ template<typename _Tp, _Lock_policy _Lp>
+ struct less<__shared_ptr<_Tp, _Lp>>
+ : public _Sp_less<__shared_ptr<_Tp, _Lp>>
+ { };
+
+ // 2.2.3.8 shared_ptr specialized algorithms.
+ template<typename _Tp, _Lock_policy _Lp>
+ inline void
+ swap(__shared_ptr<_Tp, _Lp>& __a, __shared_ptr<_Tp, _Lp>& __b) noexcept
+ { __a.swap(__b); }
+
+ // 2.2.3.9 shared_ptr casts
+
+ // The seemingly equivalent code:
+ // shared_ptr<_Tp, _Lp>(static_cast<_Tp*>(__r.get()))
+ // will eventually result in undefined behaviour, attempting to
+ // delete the same object twice.
+ /// static_pointer_cast
+ template<typename _Tp, typename _Tp1, _Lock_policy _Lp>
+ inline __shared_ptr<_Tp, _Lp>
+ static_pointer_cast(const __shared_ptr<_Tp1, _Lp>& __r) noexcept
+ { return __shared_ptr<_Tp, _Lp>(__r, static_cast<_Tp*>(__r.get())); }
+
+ // The seemingly equivalent code:
+ // shared_ptr<_Tp, _Lp>(const_cast<_Tp*>(__r.get()))
+ // will eventually result in undefined behaviour, attempting to
+ // delete the same object twice.
+ /// const_pointer_cast
+ template<typename _Tp, typename _Tp1, _Lock_policy _Lp>
+ inline __shared_ptr<_Tp, _Lp>
+ const_pointer_cast(const __shared_ptr<_Tp1, _Lp>& __r) noexcept
+ { return __shared_ptr<_Tp, _Lp>(__r, const_cast<_Tp*>(__r.get())); }
+
+ // The seemingly equivalent code:
+ // shared_ptr<_Tp, _Lp>(dynamic_cast<_Tp*>(__r.get()))
+ // will eventually result in undefined behaviour, attempting to
+ // delete the same object twice.
+ /// dynamic_pointer_cast
+ template<typename _Tp, typename _Tp1, _Lock_policy _Lp>
+ inline __shared_ptr<_Tp, _Lp>
+ dynamic_pointer_cast(const __shared_ptr<_Tp1, _Lp>& __r) noexcept
+ {
+ if (_Tp* __p = dynamic_cast<_Tp*>(__r.get()))
+ return __shared_ptr<_Tp, _Lp>(__r, __p);
+ return __shared_ptr<_Tp, _Lp>();
+ }
+
+
+ template<typename _Tp, _Lock_policy _Lp>
+ class __weak_ptr
+ {
+ public:
+ typedef _Tp element_type;
+
+ constexpr __weak_ptr() noexcept
+ : _M_ptr(0), _M_refcount()
+ { }
+
+ __weak_ptr(const __weak_ptr&) noexcept = default;
+ __weak_ptr& operator=(const __weak_ptr&) noexcept = default;
+ ~__weak_ptr() = default;
+
+ // The "obvious" converting constructor implementation:
+ //
+ // template<typename _Tp1>
+ // __weak_ptr(const __weak_ptr<_Tp1, _Lp>& __r)
+ // : _M_ptr(__r._M_ptr), _M_refcount(__r._M_refcount) // never throws
+ // { }
+ //
+ // has a serious problem.
+ //
+ // __r._M_ptr may already have been invalidated. The _M_ptr(__r._M_ptr)
+ // conversion may require access to *__r._M_ptr (virtual inheritance).
+ //
+ // It is not possible to avoid spurious access violations since
+ // in multithreaded programs __r._M_ptr may be invalidated at any point.
+ template<typename _Tp1, typename = typename
+ std::enable_if<std::is_convertible<_Tp1*, _Tp*>::value>::type>
+ __weak_ptr(const __weak_ptr<_Tp1, _Lp>& __r) noexcept
+ : _M_refcount(__r._M_refcount)
+ { _M_ptr = __r.lock().get(); }
+
+ template<typename _Tp1, typename = typename
+ std::enable_if<std::is_convertible<_Tp1*, _Tp*>::value>::type>
+ __weak_ptr(const __shared_ptr<_Tp1, _Lp>& __r) noexcept
+ : _M_ptr(__r._M_ptr), _M_refcount(__r._M_refcount)
+ { }
+
+ template<typename _Tp1>
+ __weak_ptr&
+ operator=(const __weak_ptr<_Tp1, _Lp>& __r) noexcept
+ {
+ _M_ptr = __r.lock().get();
+ _M_refcount = __r._M_refcount;
+ return *this;
+ }
+
+ template<typename _Tp1>
+ __weak_ptr&
+ operator=(const __shared_ptr<_Tp1, _Lp>& __r) noexcept
+ {
+ _M_ptr = __r._M_ptr;
+ _M_refcount = __r._M_refcount;
+ return *this;
+ }
+
+ __shared_ptr<_Tp, _Lp>
+ lock() const noexcept
+ {
+#ifdef __GTHREADS
+ // Optimization: avoid throw overhead.
+ if (expired())
+ return __shared_ptr<element_type, _Lp>();
+
+ __try
+ {
+ return __shared_ptr<element_type, _Lp>(*this);
+ }
+ __catch(const bad_weak_ptr&)
+ {
+ // Q: How can we get here?
+ // A: Another thread may have invalidated r after the
+ // use_count test above.
+ return __shared_ptr<element_type, _Lp>();
+ }
+
+#else
+ // Optimization: avoid try/catch overhead when single threaded.
+ return expired() ? __shared_ptr<element_type, _Lp>()
+ : __shared_ptr<element_type, _Lp>(*this);
+
+#endif
+ } // XXX MT
+
+ long
+ use_count() const noexcept
+ { return _M_refcount._M_get_use_count(); }
+
+ bool
+ expired() const noexcept
+ { return _M_refcount._M_get_use_count() == 0; }
+
+ template<typename _Tp1>
+ bool
+ owner_before(const __shared_ptr<_Tp1, _Lp>& __rhs) const
+ { return _M_refcount._M_less(__rhs._M_refcount); }
+
+ template<typename _Tp1>
+ bool
+ owner_before(const __weak_ptr<_Tp1, _Lp>& __rhs) const
+ { return _M_refcount._M_less(__rhs._M_refcount); }
+
+ void
+ reset() noexcept
+ { __weak_ptr().swap(*this); }
+
+ void
+ swap(__weak_ptr& __s) noexcept
+ {
+ std::swap(_M_ptr, __s._M_ptr);
+ _M_refcount._M_swap(__s._M_refcount);
+ }
+
+ private:
+ // Used by __enable_shared_from_this.
+ void
+ _M_assign(_Tp* __ptr, const __shared_count<_Lp>& __refcount) noexcept
+ {
+ _M_ptr = __ptr;
+ _M_refcount = __refcount;
+ }
+
+ template<typename _Tp1, _Lock_policy _Lp1> friend class __shared_ptr;
+ template<typename _Tp1, _Lock_policy _Lp1> friend class __weak_ptr;
+ friend class __enable_shared_from_this<_Tp, _Lp>;
+ friend class enable_shared_from_this<_Tp>;
+
+ _Tp* _M_ptr; // Contained pointer.
+ __weak_count<_Lp> _M_refcount; // Reference counter.
+ };
+
+ // 20.8.13.3.7 weak_ptr specialized algorithms.
+ template<typename _Tp, _Lock_policy _Lp>
+ inline void
+ swap(__weak_ptr<_Tp, _Lp>& __a, __weak_ptr<_Tp, _Lp>& __b) noexcept
+ { __a.swap(__b); }
+
+ template<typename _Tp, typename _Tp1>
+ struct _Sp_owner_less : public binary_function<_Tp, _Tp, bool>
+ {
+ bool
+ operator()(const _Tp& __lhs, const _Tp& __rhs) const
+ { return __lhs.owner_before(__rhs); }
+
+ bool
+ operator()(const _Tp& __lhs, const _Tp1& __rhs) const
+ { return __lhs.owner_before(__rhs); }
+
+ bool
+ operator()(const _Tp1& __lhs, const _Tp& __rhs) const
+ { return __lhs.owner_before(__rhs); }
+ };
+
+ template<typename _Tp, _Lock_policy _Lp>
+ struct owner_less<__shared_ptr<_Tp, _Lp>>
+ : public _Sp_owner_less<__shared_ptr<_Tp, _Lp>, __weak_ptr<_Tp, _Lp>>
+ { };
+
+ template<typename _Tp, _Lock_policy _Lp>
+ struct owner_less<__weak_ptr<_Tp, _Lp>>
+ : public _Sp_owner_less<__weak_ptr<_Tp, _Lp>, __shared_ptr<_Tp, _Lp>>
+ { };
+
+
+ template<typename _Tp, _Lock_policy _Lp>
+ class __enable_shared_from_this
+ {
+ protected:
+ constexpr __enable_shared_from_this() noexcept { }
+
+ __enable_shared_from_this(const __enable_shared_from_this&) noexcept { }
+
+ __enable_shared_from_this&
+ operator=(const __enable_shared_from_this&) noexcept
+ { return *this; }
+
+ ~__enable_shared_from_this() { }
+
+ public:
+ __shared_ptr<_Tp, _Lp>
+ shared_from_this()
+ { return __shared_ptr<_Tp, _Lp>(this->_M_weak_this); }
+
+ __shared_ptr<const _Tp, _Lp>
+ shared_from_this() const
+ { return __shared_ptr<const _Tp, _Lp>(this->_M_weak_this); }
+
+ private:
+ template<typename _Tp1>
+ void
+ _M_weak_assign(_Tp1* __p, const __shared_count<_Lp>& __n) const noexcept
+ { _M_weak_this._M_assign(__p, __n); }
+
+ template<typename _Tp1>
+ friend void
+ __enable_shared_from_this_helper(const __shared_count<_Lp>& __pn,
+ const __enable_shared_from_this* __pe,
+ const _Tp1* __px) noexcept
+ {
+ if (__pe != 0)
+ __pe->_M_weak_assign(const_cast<_Tp1*>(__px), __pn);
+ }
+
+ mutable __weak_ptr<_Tp, _Lp> _M_weak_this;
+ };
+
+
+ template<typename _Tp, _Lock_policy _Lp, typename _Alloc, typename... _Args>
+ inline __shared_ptr<_Tp, _Lp>
+ __allocate_shared(const _Alloc& __a, _Args&&... __args)
+ {
+ return __shared_ptr<_Tp, _Lp>(_Sp_make_shared_tag(), __a,
+ std::forward<_Args>(__args)...);
+ }
+
+ template<typename _Tp, _Lock_policy _Lp, typename... _Args>
+ inline __shared_ptr<_Tp, _Lp>
+ __make_shared(_Args&&... __args)
+ {
+ typedef typename std::remove_const<_Tp>::type _Tp_nc;
+ return std::__allocate_shared<_Tp, _Lp>(std::allocator<_Tp_nc>(),
+ std::forward<_Args>(__args)...);
+ }
+
+ /// std::hash specialization for __shared_ptr.
+ template<typename _Tp, _Lock_policy _Lp>
+ struct hash<__shared_ptr<_Tp, _Lp>>
+ : public __hash_base<size_t, __shared_ptr<_Tp, _Lp>>
+ {
+ size_t
+ operator()(const __shared_ptr<_Tp, _Lp>& __s) const noexcept
+ { return std::hash<_Tp*>()(__s.get()); }
+ };
+
+_GLIBCXX_END_NAMESPACE_VERSION
+} // namespace
+
+#endif // _SHARED_PTR_BASE_H
projects / cross.git / blobdiff