aarch64-linux-gnu-4.9/aarch64-linux-gnu/include/c++/4.9.4/bits/shared_ptr.h - toolchains/linux-x86/gcc - Git at Google

 // shared_ptr and weak_ptr implementation -*- C++ -*-

 // Copyright (C) 2007-2014 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.h
  *  This is an internal header file, included by other library headers.
  *  Do not attempt to use it directly. @headername{memory}
  */

 #ifndef _SHARED_PTR_H
 #define _SHARED_PTR_H 1

 #include <bits/shared_ptr_base.h>

 namespace std _GLIBCXX_VISIBILITY(default)
 {
 _GLIBCXX_BEGIN_NAMESPACE_VERSION

   /**
    * @addtogroup pointer_abstractions
    * @{
    */

   /// 20.7.2.2.11 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;
     }

   /// 20.7.2.2.10 shared_ptr get_deleter
   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
     }


   /**
    *  @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>() { }

       shared_ptr(const shared_ptr&) noexcept = default;

       /**
        *  @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) { }

       /**
        *  @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) { }

       /**
        *  @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) { }

       /**
        *  @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)) { }

       /**
        *  @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)) { }

       // Aliasing constructor

       /**
        *  @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) { }

       /**
        *  @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) { }

       /**
        *  @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)) { }

       /**
        *  @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)) { }

       /**
        *  @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) { }

 #if _GLIBCXX_USE_DEPRECATED
       template<typename _Tp1>
 	shared_ptr(std::auto_ptr<_Tp1>&& __r);
 #endif

       template<typename _Tp1, typename _Del>
 	shared_ptr(std::unique_ptr<_Tp1, _Del>&& __r)
 	: __shared_ptr<_Tp>(std::move(__r)) { }

       /**
        *  @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) { }

       shared_ptr& operator=(const shared_ptr&) noexcept = default;

       template<typename _Tp1>
 	shared_ptr&
 	operator=(const shared_ptr<_Tp1>& __r) noexcept
 	{
 	  this->__shared_ptr<_Tp>::operator=(__r);
 	  return *this;
 	}

 #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

       shared_ptr&
       operator=(shared_ptr&& __r) noexcept
       {
 	this->__shared_ptr<_Tp>::operator=(std::move(__r));
 	return *this;
       }

       template<class _Tp1>
 	shared_ptr&
 	operator=(shared_ptr<_Tp1>&& __r) noexcept
 	{
 	  this->__shared_ptr<_Tp>::operator=(std::move(__r));
 	  return *this;
 	}

       template<typename _Tp1, typename _Del>
 	shared_ptr&
 	operator=(std::unique_ptr<_Tp1, _Del>&& __r)
 	{
 	  this->__shared_ptr<_Tp>::operator=(std::move(__r));
 	  return *this;
 	}

     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)...)
 	{ }

       template<typename _Tp1, typename _Alloc, typename... _Args>
 	friend shared_ptr<_Tp1>
 	allocate_shared(const _Alloc& __a, _Args&&... __args);

       // This constructor is non-standard, it is used by weak_ptr::lock().
       shared_ptr(const weak_ptr<_Tp>& __r, std::nothrow_t)
       : __shared_ptr<_Tp>(__r, std::nothrow) { }

       friend class weak_ptr<_Tp>;
     };

   // 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(); }

   template<typename _Tp>
     inline bool
     operator==(const shared_ptr<_Tp>& __a, nullptr_t) noexcept
     { return !__a; }

   template<typename _Tp>
     inline bool
     operator==(nullptr_t, const shared_ptr<_Tp>& __a) noexcept
     { return !__a; }

   template<typename _Tp1, typename _Tp2>
     inline bool
     operator!=(const shared_ptr<_Tp1>& __a,
 	       const shared_ptr<_Tp2>& __b) noexcept
     { return __a.get() != __b.get(); }

   template<typename _Tp>
     inline bool
     operator!=(const shared_ptr<_Tp>& __a, nullptr_t) noexcept
     { return (bool)__a; }

   template<typename _Tp>
     inline bool
     operator!=(nullptr_t, const shared_ptr<_Tp>& __a) noexcept
     { return (bool)__a; }

   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());
     }

   template<typename _Tp>
     inline bool
     operator<(const shared_ptr<_Tp>& __a, nullptr_t) noexcept
     { return std::less<_Tp*>()(__a.get(), nullptr); }

   template<typename _Tp>
     inline bool
     operator<(nullptr_t, const shared_ptr<_Tp>& __a) noexcept
     { return std::less<_Tp*>()(nullptr, __a.get()); }

   template<typename _Tp1, typename _Tp2>
     inline bool
     operator<=(const shared_ptr<_Tp1>& __a,
 	       const shared_ptr<_Tp2>& __b) noexcept
     { return !(__b < __a); }

   template<typename _Tp>
     inline bool
     operator<=(const shared_ptr<_Tp>& __a, nullptr_t) noexcept
     { return !(nullptr < __a); }

   template<typename _Tp>
     inline bool
     operator<=(nullptr_t, const shared_ptr<_Tp>& __a) noexcept
     { return !(__a < nullptr); }

   template<typename _Tp1, typename _Tp2>
     inline bool
     operator>(const shared_ptr<_Tp1>& __a,
 	      const shared_ptr<_Tp2>& __b) noexcept
     { return (__b < __a); }

   template<typename _Tp>
     inline bool
     operator>(const shared_ptr<_Tp>& __a, nullptr_t) noexcept
     { return std::less<_Tp*>()(nullptr, __a.get()); }

   template<typename _Tp>
     inline bool
     operator>(nullptr_t, const shared_ptr<_Tp>& __a) noexcept
     { return std::less<_Tp*>()(__a.get(), nullptr); }

   template<typename _Tp1, typename _Tp2>
     inline bool
     operator>=(const shared_ptr<_Tp1>& __a,
 	       const shared_ptr<_Tp2>& __b) noexcept
     { return !(__a < __b); }

   template<typename _Tp>
     inline bool
     operator>=(const shared_ptr<_Tp>& __a, nullptr_t) noexcept
     { return !(__a < nullptr); }

   template<typename _Tp>
     inline bool
     operator>=(nullptr_t, const shared_ptr<_Tp>& __a) noexcept
     { return !(nullptr < __a); }

   template<typename _Tp>
     struct less<shared_ptr<_Tp>> : public _Sp_less<shared_ptr<_Tp>>
     { };

   // 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); }

   // 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())); }

   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())); }

   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>();
     }


   /**
    *  @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>() { }

       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) { }

       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) { }

       template<typename _Tp1>
 	weak_ptr&
 	operator=(const weak_ptr<_Tp1>& __r) noexcept
 	{
 	  this->__weak_ptr<_Tp>::operator=(__r);
 	  return *this;
 	}

       template<typename _Tp1>
 	weak_ptr&
 	operator=(const shared_ptr<_Tp1>& __r) noexcept
 	{
 	  this->__weak_ptr<_Tp>::operator=(__r);
 	  return *this;
 	}

       shared_ptr<_Tp>
       lock() const noexcept
       { return shared_ptr<_Tp>(*this, std::nothrow); }
     };

   // 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); }


   /// Primary template owner_less
   template<typename _Tp>
     struct owner_less;

   /// 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>>
     { };

   /// 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>>
     { };

   /**
    *  @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 { }

       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>
       shared_from_this()
       { return shared_ptr<_Tp>(this->_M_weak_this); }

       shared_ptr<const _Tp>
       shared_from_this() const
       { return shared_ptr<const _Tp>(this->_M_weak_this); }

     private:
       template<typename _Tp1>
 	void
 	_M_weak_assign(_Tp1* __p, const __shared_count<>& __n) const noexcept
 	{ _M_weak_this._M_assign(__p, __n); }

       template<typename _Tp1, typename _Tp2>
 	friend void
 	__enable_shared_from_this_helper(const __shared_count<>&,
 					 const enable_shared_from_this<_Tp1>*,
 					 const _Tp2*) noexcept;

       mutable weak_ptr<_Tp>  _M_weak_this;
     };

   template<typename _Tp1, typename _Tp2>
     inline void
     __enable_shared_from_this_helper(const __shared_count<>& __pn,
 				     const enable_shared_from_this<_Tp1>*
 				     __pe, const _Tp2* __px) noexcept
     {
       if (__pe != nullptr)
 	__pe->_M_weak_assign(const_cast<_Tp2*>(__px), __pn);
     }

   /**
    *  @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)...);
     }

   /**
    *  @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)...);
     }

   /// 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()); }
     };

   // @} group pointer_abstractions

 _GLIBCXX_END_NAMESPACE_VERSION
 } // namespace

 #endif // _SHARED_PTR_H
	// shared_ptr and weak_ptr implementation -- C++ --

	// Copyright (C) 2007-2014 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.h
	* This is an internal header file, included by other library headers.
	* Do not attempt to use it directly. @headername{memory}
	*/

	#ifndef _SHARED_PTR_H
	#define _SHARED_PTR_H 1

	#include <bits/shared_ptr_base.h>

	namespace std _GLIBCXX_VISIBILITY(default)
	{
	_GLIBCXX_BEGIN_NAMESPACE_VERSION

	/**
	* @addtogroup pointer_abstractions
	* @{
	*/

	/// 20.7.2.2.11 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;
	}

	/// 20.7.2.2.10 shared_ptr get_deleter
	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
	}


	/**
	* @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>() { }

	shared_ptr(const shared_ptr&) noexcept = default;

	/**
	* @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) { }

	/**
	* @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) { }

	/**
	* @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) { }

	/**
	* @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)) { }

	/**
	* @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)) { }

	// Aliasing constructor

	/**
	* @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) { }

	/**
	* @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) { }

	/**
	* @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)) { }

	/**
	* @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)) { }

	/**
	* @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) { }

	#if _GLIBCXX_USE_DEPRECATED
	template<typename _Tp1>
	shared_ptr(std::auto_ptr<_Tp1>&& __r);
	#endif

	template<typename _Tp1, typename _Del>
	shared_ptr(std::unique_ptr<_Tp1, _Del>&& __r)
	: __shared_ptr<_Tp>(std::move(__r)) { }

	/**
	* @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) { }

	shared_ptr& operator=(const shared_ptr&) noexcept = default;

	template<typename _Tp1>
	shared_ptr&
	operator=(const shared_ptr<_Tp1>& __r) noexcept
	{
	this->__shared_ptr<_Tp>::operator=(__r);
	return *this;
	}

	#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

	shared_ptr&
	operator=(shared_ptr&& __r) noexcept
	{
	this->__shared_ptr<_Tp>::operator=(std::move(__r));
	return *this;
	}

	template<class _Tp1>
	shared_ptr&
	operator=(shared_ptr<_Tp1>&& __r) noexcept
	{
	this->__shared_ptr<_Tp>::operator=(std::move(__r));
	return *this;
	}

	template<typename _Tp1, typename _Del>
	shared_ptr&
	operator=(std::unique_ptr<_Tp1, _Del>&& __r)
	{
	this->__shared_ptr<_Tp>::operator=(std::move(__r));
	return *this;
	}

	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)...)
	{ }

	template<typename _Tp1, typename _Alloc, typename... _Args>
	friend shared_ptr<_Tp1>
	allocate_shared(const _Alloc& __a, _Args&&... __args);

	// This constructor is non-standard, it is used by weak_ptr::lock().
	shared_ptr(const weak_ptr<_Tp>& __r, std::nothrow_t)
	: __shared_ptr<_Tp>(__r, std::nothrow) { }

	friend class weak_ptr<_Tp>;
	};

	// 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(); }

	template<typename _Tp>
	inline bool
	operator==(const shared_ptr<_Tp>& __a, nullptr_t) noexcept
	{ return !__a; }

	template<typename _Tp>
	inline bool
	operator==(nullptr_t, const shared_ptr<_Tp>& __a) noexcept
	{ return !__a; }

	template<typename _Tp1, typename _Tp2>
	inline bool
	operator!=(const shared_ptr<_Tp1>& __a,
	const shared_ptr<_Tp2>& __b) noexcept
	{ return __a.get() != __b.get(); }

	template<typename _Tp>
	inline bool
	operator!=(const shared_ptr<_Tp>& __a, nullptr_t) noexcept
	{ return (bool)__a; }

	template<typename _Tp>
	inline bool
	operator!=(nullptr_t, const shared_ptr<_Tp>& __a) noexcept
	{ return (bool)__a; }

	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());
	}

	template<typename _Tp>
	inline bool
	operator<(const shared_ptr<_Tp>& __a, nullptr_t) noexcept
	{ return std::less<_Tp*>()(__a.get(), nullptr); }

	template<typename _Tp>
	inline bool
	operator<(nullptr_t, const shared_ptr<_Tp>& __a) noexcept
	{ return std::less<_Tp*>()(nullptr, __a.get()); }

	template<typename _Tp1, typename _Tp2>
	inline bool
	operator<=(const shared_ptr<_Tp1>& __a,
	const shared_ptr<_Tp2>& __b) noexcept
	{ return !(__b < __a); }

	template<typename _Tp>
	inline bool
	operator<=(const shared_ptr<_Tp>& __a, nullptr_t) noexcept
	{ return !(nullptr < __a); }

	template<typename _Tp>
	inline bool
	operator<=(nullptr_t, const shared_ptr<_Tp>& __a) noexcept
	{ return !(__a < nullptr); }

	template<typename _Tp1, typename _Tp2>
	inline bool
	operator>(const shared_ptr<_Tp1>& __a,
	const shared_ptr<_Tp2>& __b) noexcept
	{ return (__b < __a); }

	template<typename _Tp>
	inline bool
	operator>(const shared_ptr<_Tp>& __a, nullptr_t) noexcept
	{ return std::less<_Tp*>()(nullptr, __a.get()); }

	template<typename _Tp>
	inline bool
	operator>(nullptr_t, const shared_ptr<_Tp>& __a) noexcept
	{ return std::less<_Tp*>()(__a.get(), nullptr); }

	template<typename _Tp1, typename _Tp2>
	inline bool
	operator>=(const shared_ptr<_Tp1>& __a,
	const shared_ptr<_Tp2>& __b) noexcept
	{ return !(__a < __b); }

	template<typename _Tp>
	inline bool
	operator>=(const shared_ptr<_Tp>& __a, nullptr_t) noexcept
	{ return !(__a < nullptr); }

	template<typename _Tp>
	inline bool
	operator>=(nullptr_t, const shared_ptr<_Tp>& __a) noexcept
	{ return !(nullptr < __a); }

	template<typename _Tp>
	struct less<shared_ptr<_Tp>> : public _Sp_less<shared_ptr<_Tp>>
	{ };

	// 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); }

	// 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())); }

	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())); }

	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>();
	}


	/**
	* @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>() { }

	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) { }

	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) { }

	template<typename _Tp1>
	weak_ptr&
	operator=(const weak_ptr<_Tp1>& __r) noexcept
	{
	this->__weak_ptr<_Tp>::operator=(__r);
	return *this;
	}

	template<typename _Tp1>
	weak_ptr&
	operator=(const shared_ptr<_Tp1>& __r) noexcept
	{
	this->__weak_ptr<_Tp>::operator=(__r);
	return *this;
	}

	shared_ptr<_Tp>
	lock() const noexcept
	{ return shared_ptr<_Tp>(*this, std::nothrow); }
	};

	// 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); }


	/// Primary template owner_less
	template<typename _Tp>
	struct owner_less;

	/// 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>>
	{ };

	/// 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>>
	{ };

	/**
	* @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 { }

	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>
	shared_from_this()
	{ return shared_ptr<_Tp>(this->_M_weak_this); }

	shared_ptr<const _Tp>
	shared_from_this() const
	{ return shared_ptr<const _Tp>(this->_M_weak_this); }

	private:
	template<typename _Tp1>
	void
	_M_weak_assign(_Tp1* __p, const __shared_count<>& __n) const noexcept
	{ _M_weak_this._M_assign(__p, __n); }

	template<typename _Tp1, typename _Tp2>
	friend void
	__enable_shared_from_this_helper(const __shared_count<>&,
	const enable_shared_from_this<_Tp1>*,
	const _Tp2*) noexcept;

	mutable weak_ptr<_Tp> _M_weak_this;
	};

	template<typename _Tp1, typename _Tp2>
	inline void
	__enable_shared_from_this_helper(const __shared_count<>& __pn,
	const enable_shared_from_this<_Tp1>*
	__pe, const _Tp2* __px) noexcept
	{
	if (__pe != nullptr)
	__pe->_M_weak_assign(const_cast<_Tp2*>(__px), __pn);
	}

	/**
	* @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)...);
	}

	/**
	* @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)...);
	}

	/// 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()); }
	};

	// @} group pointer_abstractions

	_GLIBCXX_END_NAMESPACE_VERSION
	} // namespace

	#endif // _SHARED_PTR_H