0,0 → 1,632 |
// shared_ptr and weak_ptr implementation -*- C++ -*- |
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// Copyright (C) 2007-2013 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. |
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// 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. |
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// 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. |
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// 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/>. |
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// GCC Note: Based on files from version 1.32.0 of the Boost library. |
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// shared_count.hpp |
// Copyright (c) 2001, 2002, 2003 Peter Dimov and Multi Media Ltd. |
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// shared_ptr.hpp |
// Copyright (C) 1998, 1999 Greg Colvin and Beman Dawes. |
// Copyright (C) 2001, 2002, 2003 Peter Dimov |
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// weak_ptr.hpp |
// Copyright (C) 2001, 2002, 2003 Peter Dimov |
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// enable_shared_from_this.hpp |
// Copyright (C) 2002 Peter Dimov |
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// 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) |
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/** @file bits/shared_ptr.h |
* This is an internal header file, included by other library headers. |
* Do not attempt to use it directly. @headername{memory} |
*/ |
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#ifndef _SHARED_PTR_H |
#define _SHARED_PTR_H 1 |
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#include <bits/shared_ptr_base.h> |
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namespace std _GLIBCXX_VISIBILITY(default) |
{ |
_GLIBCXX_BEGIN_NAMESPACE_VERSION |
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/** |
* @addtogroup pointer_abstractions |
* @{ |
*/ |
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/// 2.2.3.7 shared_ptr I/O |
template<typename _Ch, typename _Tr, typename _Tp, _Lock_policy _Lp> |
inline std::basic_ostream<_Ch, _Tr>& |
operator<<(std::basic_ostream<_Ch, _Tr>& __os, |
const __shared_ptr<_Tp, _Lp>& __p) |
{ |
__os << __p.get(); |
return __os; |
} |
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/// 2.2.3.10 shared_ptr get_deleter (experimental) |
template<typename _Del, typename _Tp, _Lock_policy _Lp> |
inline _Del* |
get_deleter(const __shared_ptr<_Tp, _Lp>& __p) noexcept |
{ |
#ifdef __GXX_RTTI |
return static_cast<_Del*>(__p._M_get_deleter(typeid(_Del))); |
#else |
return 0; |
#endif |
} |
|
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/** |
* @brief A smart pointer with reference-counted copy semantics. |
* |
* The object pointed to is deleted when the last shared_ptr pointing to |
* it is destroyed or reset. |
*/ |
template<typename _Tp> |
class shared_ptr : public __shared_ptr<_Tp> |
{ |
public: |
/** |
* @brief Construct an empty %shared_ptr. |
* @post use_count()==0 && get()==0 |
*/ |
constexpr shared_ptr() noexcept |
: __shared_ptr<_Tp>() { } |
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shared_ptr(const shared_ptr&) noexcept = default; |
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/** |
* @brief Construct a %shared_ptr that owns the pointer @a __p. |
* @param __p A pointer that is convertible to element_type*. |
* @post use_count() == 1 && get() == __p |
* @throw std::bad_alloc, in which case @c delete @a __p is called. |
*/ |
template<typename _Tp1> |
explicit shared_ptr(_Tp1* __p) |
: __shared_ptr<_Tp>(__p) { } |
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/** |
* @brief Construct a %shared_ptr that owns the pointer @a __p |
* and the deleter @a __d. |
* @param __p A pointer. |
* @param __d A deleter. |
* @post use_count() == 1 && get() == __p |
* @throw std::bad_alloc, in which case @a __d(__p) is called. |
* |
* Requirements: _Deleter's copy constructor and destructor must |
* not throw |
* |
* __shared_ptr will release __p by calling __d(__p) |
*/ |
template<typename _Tp1, typename _Deleter> |
shared_ptr(_Tp1* __p, _Deleter __d) |
: __shared_ptr<_Tp>(__p, __d) { } |
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/** |
* @brief Construct a %shared_ptr that owns a null pointer |
* and the deleter @a __d. |
* @param __p A null pointer constant. |
* @param __d A deleter. |
* @post use_count() == 1 && get() == __p |
* @throw std::bad_alloc, in which case @a __d(__p) is called. |
* |
* Requirements: _Deleter's copy constructor and destructor must |
* not throw |
* |
* The last owner will call __d(__p) |
*/ |
template<typename _Deleter> |
shared_ptr(nullptr_t __p, _Deleter __d) |
: __shared_ptr<_Tp>(__p, __d) { } |
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/** |
* @brief Construct a %shared_ptr that owns the pointer @a __p |
* and the deleter @a __d. |
* @param __p A pointer. |
* @param __d A deleter. |
* @param __a An allocator. |
* @post use_count() == 1 && get() == __p |
* @throw std::bad_alloc, in which case @a __d(__p) is called. |
* |
* Requirements: _Deleter's copy constructor and destructor must |
* not throw _Alloc's copy constructor and destructor must not |
* throw. |
* |
* __shared_ptr will release __p by calling __d(__p) |
*/ |
template<typename _Tp1, typename _Deleter, typename _Alloc> |
shared_ptr(_Tp1* __p, _Deleter __d, _Alloc __a) |
: __shared_ptr<_Tp>(__p, __d, std::move(__a)) { } |
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/** |
* @brief Construct a %shared_ptr that owns a null pointer |
* and the deleter @a __d. |
* @param __p A null pointer constant. |
* @param __d A deleter. |
* @param __a An allocator. |
* @post use_count() == 1 && get() == __p |
* @throw std::bad_alloc, in which case @a __d(__p) is called. |
* |
* Requirements: _Deleter's copy constructor and destructor must |
* not throw _Alloc's copy constructor and destructor must not |
* throw. |
* |
* The last owner will call __d(__p) |
*/ |
template<typename _Deleter, typename _Alloc> |
shared_ptr(nullptr_t __p, _Deleter __d, _Alloc __a) |
: __shared_ptr<_Tp>(__p, __d, std::move(__a)) { } |
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// Aliasing constructor |
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/** |
* @brief Constructs a %shared_ptr instance that stores @a __p |
* and shares ownership with @a __r. |
* @param __r A %shared_ptr. |
* @param __p A pointer that will remain valid while @a *__r is valid. |
* @post get() == __p && use_count() == __r.use_count() |
* |
* This can be used to construct a @c shared_ptr to a sub-object |
* of an object managed by an existing @c shared_ptr. |
* |
* @code |
* shared_ptr< pair<int,int> > pii(new pair<int,int>()); |
* shared_ptr<int> pi(pii, &pii->first); |
* assert(pii.use_count() == 2); |
* @endcode |
*/ |
template<typename _Tp1> |
shared_ptr(const shared_ptr<_Tp1>& __r, _Tp* __p) noexcept |
: __shared_ptr<_Tp>(__r, __p) { } |
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/** |
* @brief If @a __r is empty, constructs an empty %shared_ptr; |
* otherwise construct a %shared_ptr that shares ownership |
* with @a __r. |
* @param __r A %shared_ptr. |
* @post get() == __r.get() && use_count() == __r.use_count() |
*/ |
template<typename _Tp1, typename = typename |
std::enable_if<std::is_convertible<_Tp1*, _Tp*>::value>::type> |
shared_ptr(const shared_ptr<_Tp1>& __r) noexcept |
: __shared_ptr<_Tp>(__r) { } |
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/** |
* @brief Move-constructs a %shared_ptr instance from @a __r. |
* @param __r A %shared_ptr rvalue. |
* @post *this contains the old value of @a __r, @a __r is empty. |
*/ |
shared_ptr(shared_ptr&& __r) noexcept |
: __shared_ptr<_Tp>(std::move(__r)) { } |
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/** |
* @brief Move-constructs a %shared_ptr instance from @a __r. |
* @param __r A %shared_ptr rvalue. |
* @post *this contains the old value of @a __r, @a __r is empty. |
*/ |
template<typename _Tp1, typename = typename |
std::enable_if<std::is_convertible<_Tp1*, _Tp*>::value>::type> |
shared_ptr(shared_ptr<_Tp1>&& __r) noexcept |
: __shared_ptr<_Tp>(std::move(__r)) { } |
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/** |
* @brief Constructs a %shared_ptr that shares ownership with @a __r |
* and stores a copy of the pointer stored in @a __r. |
* @param __r A weak_ptr. |
* @post use_count() == __r.use_count() |
* @throw bad_weak_ptr when __r.expired(), |
* in which case the constructor has no effect. |
*/ |
template<typename _Tp1> |
explicit shared_ptr(const weak_ptr<_Tp1>& __r) |
: __shared_ptr<_Tp>(__r) { } |
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#if _GLIBCXX_USE_DEPRECATED |
template<typename _Tp1> |
shared_ptr(std::auto_ptr<_Tp1>&& __r); |
#endif |
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template<typename _Tp1, typename _Del> |
shared_ptr(std::unique_ptr<_Tp1, _Del>&& __r) |
: __shared_ptr<_Tp>(std::move(__r)) { } |
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/** |
* @brief Construct an empty %shared_ptr. |
* @param __p A null pointer constant. |
* @post use_count() == 0 && get() == nullptr |
*/ |
constexpr shared_ptr(nullptr_t __p) noexcept |
: __shared_ptr<_Tp>(__p) { } |
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shared_ptr& operator=(const shared_ptr&) noexcept = default; |
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template<typename _Tp1> |
shared_ptr& |
operator=(const shared_ptr<_Tp1>& __r) noexcept |
{ |
this->__shared_ptr<_Tp>::operator=(__r); |
return *this; |
} |
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#if _GLIBCXX_USE_DEPRECATED |
template<typename _Tp1> |
shared_ptr& |
operator=(std::auto_ptr<_Tp1>&& __r) |
{ |
this->__shared_ptr<_Tp>::operator=(std::move(__r)); |
return *this; |
} |
#endif |
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shared_ptr& |
operator=(shared_ptr&& __r) noexcept |
{ |
this->__shared_ptr<_Tp>::operator=(std::move(__r)); |
return *this; |
} |
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template<class _Tp1> |
shared_ptr& |
operator=(shared_ptr<_Tp1>&& __r) noexcept |
{ |
this->__shared_ptr<_Tp>::operator=(std::move(__r)); |
return *this; |
} |
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template<typename _Tp1, typename _Del> |
shared_ptr& |
operator=(std::unique_ptr<_Tp1, _Del>&& __r) |
{ |
this->__shared_ptr<_Tp>::operator=(std::move(__r)); |
return *this; |
} |
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private: |
// 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) |
: __shared_ptr<_Tp>(__tag, __a, std::forward<_Args>(__args)...) |
{ } |
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template<typename _Tp1, typename _Alloc, typename... _Args> |
friend shared_ptr<_Tp1> |
allocate_shared(const _Alloc& __a, _Args&&... __args); |
}; |
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// 20.7.2.2.7 shared_ptr comparisons |
template<typename _Tp1, typename _Tp2> |
inline bool |
operator==(const shared_ptr<_Tp1>& __a, |
const shared_ptr<_Tp2>& __b) noexcept |
{ return __a.get() == __b.get(); } |
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template<typename _Tp> |
inline bool |
operator==(const shared_ptr<_Tp>& __a, nullptr_t) noexcept |
{ return !__a; } |
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template<typename _Tp> |
inline bool |
operator==(nullptr_t, const shared_ptr<_Tp>& __a) noexcept |
{ return !__a; } |
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template<typename _Tp1, typename _Tp2> |
inline bool |
operator!=(const shared_ptr<_Tp1>& __a, |
const shared_ptr<_Tp2>& __b) noexcept |
{ return __a.get() != __b.get(); } |
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template<typename _Tp> |
inline bool |
operator!=(const shared_ptr<_Tp>& __a, nullptr_t) noexcept |
{ return (bool)__a; } |
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template<typename _Tp> |
inline bool |
operator!=(nullptr_t, const shared_ptr<_Tp>& __a) noexcept |
{ return (bool)__a; } |
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template<typename _Tp1, typename _Tp2> |
inline bool |
operator<(const shared_ptr<_Tp1>& __a, |
const shared_ptr<_Tp2>& __b) noexcept |
{ |
typedef typename std::common_type<_Tp1*, _Tp2*>::type _CT; |
return std::less<_CT>()(__a.get(), __b.get()); |
} |
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template<typename _Tp> |
inline bool |
operator<(const shared_ptr<_Tp>& __a, nullptr_t) noexcept |
{ return std::less<_Tp*>()(__a.get(), nullptr); } |
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template<typename _Tp> |
inline bool |
operator<(nullptr_t, const shared_ptr<_Tp>& __a) noexcept |
{ return std::less<_Tp*>()(nullptr, __a.get()); } |
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template<typename _Tp1, typename _Tp2> |
inline bool |
operator<=(const shared_ptr<_Tp1>& __a, |
const shared_ptr<_Tp2>& __b) noexcept |
{ return !(__b < __a); } |
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template<typename _Tp> |
inline bool |
operator<=(const shared_ptr<_Tp>& __a, nullptr_t) noexcept |
{ return !(nullptr < __a); } |
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template<typename _Tp> |
inline bool |
operator<=(nullptr_t, const shared_ptr<_Tp>& __a) noexcept |
{ return !(__a < nullptr); } |
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template<typename _Tp1, typename _Tp2> |
inline bool |
operator>(const shared_ptr<_Tp1>& __a, |
const shared_ptr<_Tp2>& __b) noexcept |
{ return (__b < __a); } |
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template<typename _Tp> |
inline bool |
operator>(const shared_ptr<_Tp>& __a, nullptr_t) noexcept |
{ return std::less<_Tp*>()(nullptr, __a.get()); } |
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template<typename _Tp> |
inline bool |
operator>(nullptr_t, const shared_ptr<_Tp>& __a) noexcept |
{ return std::less<_Tp*>()(__a.get(), nullptr); } |
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template<typename _Tp1, typename _Tp2> |
inline bool |
operator>=(const shared_ptr<_Tp1>& __a, |
const shared_ptr<_Tp2>& __b) noexcept |
{ return !(__a < __b); } |
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template<typename _Tp> |
inline bool |
operator>=(const shared_ptr<_Tp>& __a, nullptr_t) noexcept |
{ return !(__a < nullptr); } |
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template<typename _Tp> |
inline bool |
operator>=(nullptr_t, const shared_ptr<_Tp>& __a) noexcept |
{ return !(nullptr < __a); } |
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template<typename _Tp> |
struct less<shared_ptr<_Tp>> : public _Sp_less<shared_ptr<_Tp>> |
{ }; |
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// 20.7.2.2.8 shared_ptr specialized algorithms. |
template<typename _Tp> |
inline void |
swap(shared_ptr<_Tp>& __a, shared_ptr<_Tp>& __b) noexcept |
{ __a.swap(__b); } |
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// 20.7.2.2.9 shared_ptr casts. |
template<typename _Tp, typename _Tp1> |
inline shared_ptr<_Tp> |
static_pointer_cast(const shared_ptr<_Tp1>& __r) noexcept |
{ return shared_ptr<_Tp>(__r, static_cast<_Tp*>(__r.get())); } |
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template<typename _Tp, typename _Tp1> |
inline shared_ptr<_Tp> |
const_pointer_cast(const shared_ptr<_Tp1>& __r) noexcept |
{ return shared_ptr<_Tp>(__r, const_cast<_Tp*>(__r.get())); } |
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template<typename _Tp, typename _Tp1> |
inline shared_ptr<_Tp> |
dynamic_pointer_cast(const shared_ptr<_Tp1>& __r) noexcept |
{ |
if (_Tp* __p = dynamic_cast<_Tp*>(__r.get())) |
return shared_ptr<_Tp>(__r, __p); |
return shared_ptr<_Tp>(); |
} |
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/** |
* @brief A smart pointer with weak semantics. |
* |
* With forwarding constructors and assignment operators. |
*/ |
template<typename _Tp> |
class weak_ptr : public __weak_ptr<_Tp> |
{ |
public: |
constexpr weak_ptr() noexcept |
: __weak_ptr<_Tp>() { } |
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template<typename _Tp1, typename = typename |
std::enable_if<std::is_convertible<_Tp1*, _Tp*>::value>::type> |
weak_ptr(const weak_ptr<_Tp1>& __r) noexcept |
: __weak_ptr<_Tp>(__r) { } |
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template<typename _Tp1, typename = typename |
std::enable_if<std::is_convertible<_Tp1*, _Tp*>::value>::type> |
weak_ptr(const shared_ptr<_Tp1>& __r) noexcept |
: __weak_ptr<_Tp>(__r) { } |
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template<typename _Tp1> |
weak_ptr& |
operator=(const weak_ptr<_Tp1>& __r) noexcept |
{ |
this->__weak_ptr<_Tp>::operator=(__r); |
return *this; |
} |
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template<typename _Tp1> |
weak_ptr& |
operator=(const shared_ptr<_Tp1>& __r) noexcept |
{ |
this->__weak_ptr<_Tp>::operator=(__r); |
return *this; |
} |
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shared_ptr<_Tp> |
lock() const noexcept |
{ |
#ifdef __GTHREADS |
if (this->expired()) |
return shared_ptr<_Tp>(); |
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__try |
{ |
return shared_ptr<_Tp>(*this); |
} |
__catch(const bad_weak_ptr&) |
{ |
return shared_ptr<_Tp>(); |
} |
#else |
return this->expired() ? shared_ptr<_Tp>() : shared_ptr<_Tp>(*this); |
#endif |
} |
}; |
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// 20.7.2.3.6 weak_ptr specialized algorithms. |
template<typename _Tp> |
inline void |
swap(weak_ptr<_Tp>& __a, weak_ptr<_Tp>& __b) noexcept |
{ __a.swap(__b); } |
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/// Primary template owner_less |
template<typename _Tp> |
struct owner_less; |
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/// Partial specialization of owner_less for shared_ptr. |
template<typename _Tp> |
struct owner_less<shared_ptr<_Tp>> |
: public _Sp_owner_less<shared_ptr<_Tp>, weak_ptr<_Tp>> |
{ }; |
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/// Partial specialization of owner_less for weak_ptr. |
template<typename _Tp> |
struct owner_less<weak_ptr<_Tp>> |
: public _Sp_owner_less<weak_ptr<_Tp>, shared_ptr<_Tp>> |
{ }; |
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/** |
* @brief Base class allowing use of member function shared_from_this. |
*/ |
template<typename _Tp> |
class enable_shared_from_this |
{ |
protected: |
constexpr enable_shared_from_this() noexcept { } |
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enable_shared_from_this(const enable_shared_from_this&) noexcept { } |
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enable_shared_from_this& |
operator=(const enable_shared_from_this&) noexcept |
{ return *this; } |
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~enable_shared_from_this() { } |
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public: |
shared_ptr<_Tp> |
shared_from_this() |
{ return shared_ptr<_Tp>(this->_M_weak_this); } |
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shared_ptr<const _Tp> |
shared_from_this() const |
{ return shared_ptr<const _Tp>(this->_M_weak_this); } |
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private: |
template<typename _Tp1> |
void |
_M_weak_assign(_Tp1* __p, const __shared_count<>& __n) const noexcept |
{ _M_weak_this._M_assign(__p, __n); } |
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template<typename _Tp1> |
friend void |
__enable_shared_from_this_helper(const __shared_count<>& __pn, |
const enable_shared_from_this* __pe, |
const _Tp1* __px) noexcept |
{ |
if (__pe != 0) |
__pe->_M_weak_assign(const_cast<_Tp1*>(__px), __pn); |
} |
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mutable weak_ptr<_Tp> _M_weak_this; |
}; |
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/** |
* @brief Create an object that is owned by a shared_ptr. |
* @param __a An allocator. |
* @param __args Arguments for the @a _Tp object's constructor. |
* @return A shared_ptr that owns the newly created object. |
* @throw An exception thrown from @a _Alloc::allocate or from the |
* constructor of @a _Tp. |
* |
* A copy of @a __a will be used to allocate memory for the shared_ptr |
* and the new object. |
*/ |
template<typename _Tp, typename _Alloc, typename... _Args> |
inline shared_ptr<_Tp> |
allocate_shared(const _Alloc& __a, _Args&&... __args) |
{ |
return shared_ptr<_Tp>(_Sp_make_shared_tag(), __a, |
std::forward<_Args>(__args)...); |
} |
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/** |
* @brief Create an object that is owned by a shared_ptr. |
* @param __args Arguments for the @a _Tp object's constructor. |
* @return A shared_ptr that owns the newly created object. |
* @throw std::bad_alloc, or an exception thrown from the |
* constructor of @a _Tp. |
*/ |
template<typename _Tp, typename... _Args> |
inline shared_ptr<_Tp> |
make_shared(_Args&&... __args) |
{ |
typedef typename std::remove_const<_Tp>::type _Tp_nc; |
return std::allocate_shared<_Tp>(std::allocator<_Tp_nc>(), |
std::forward<_Args>(__args)...); |
} |
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/// std::hash specialization for shared_ptr. |
template<typename _Tp> |
struct hash<shared_ptr<_Tp>> |
: public __hash_base<size_t, shared_ptr<_Tp>> |
{ |
size_t |
operator()(const shared_ptr<_Tp>& __s) const noexcept |
{ return std::hash<_Tp*>()(__s.get()); } |
}; |
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// @} group pointer_abstractions |
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_GLIBCXX_END_NAMESPACE_VERSION |
} // namespace |
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#endif // _SHARED_PTR_H |