#ifndef BOOST_SHARED_PTR_HPP_INCLUDED

 #define BOOST_SHARED_PTR_HPP_INCLUDED

 //

 //  shared_ptr.hpp

 //

 //  (C) Copyright Greg Colvin and Beman Dawes 1998, 1999.

 //  Copyright (c) 2001-2006 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)

 //

 //  See http://www.boost.org/libs/smart_ptr/shared_ptr.htm for documentation.

 //

 #include <boost/config.hpp>   // for broken compiler workarounds

 #if defined(BOOST_NO_MEMBER_TEMPLATES) && !defined(BOOST_MSVC6_MEMBER_TEMPLATES)

 #include <boost/detail/shared_ptr_nmt.hpp>

 #else

 #include <memory>               // for std::auto_ptr

 #include <boost/assert.hpp>

 #include <boost/checked_delete.hpp>

 #include <boost/throw_exception.hpp>

 #include <boost/detail/shared_count.hpp>

 #include <boost/detail/workaround.hpp>

 #include <algorithm>            // for std::swap

 #include <functional>           // for std::less

 #include <typeinfo>             // for std::bad_cast

 #include <iosfwd>               // for std::basic_ostream

 #ifdef BOOST_MSVC  // moved here to work around VC++ compiler crash

 # pragma warning(push)

 # pragma warning(disable:4284) // odd return type for operator->

 #endif

 namespace boost

 {

 template<class T> class weak_ptr;

 template<class T> class enable_shared_from_this;

 namespace detail

 {

 struct static_cast_tag {};

 struct const_cast_tag {};

 struct dynamic_cast_tag {};

 struct polymorphic_cast_tag {};

 template<class T> struct shared_ptr_traits

 {

     typedef T & reference;

 };

 template<> struct shared_ptr_traits<void>

 {

     typedef void reference;

 };

 #if !defined(BOOST_NO_CV_VOID_SPECIALIZATIONS)

 template<> struct shared_ptr_traits<void const>

 {

     typedef void reference;

 };

 template<> struct shared_ptr_traits<void volatile>

 {

     typedef void reference;

 };

 template<> struct shared_ptr_traits<void const volatile>

 {

     typedef void reference;

 };

 #endif

 // enable_shared_from_this support

 template<class T, class Y> void sp_enable_shared_from_this( shared_count const & pn, boost::enable_shared_from_this<T> const * pe, Y const * px )

 {

     if(pe != 0) pe->_internal_weak_this._internal_assign(const_cast<Y*>(px), pn);

 }

 #ifdef sgi

 // Turn off: the last argument of the varargs function "sp_enable_shared_from_this" is unnamed

 # pragma set woff 3506

 #endif

 inline void sp_enable_shared_from_this( shared_count const & /*pn*/, ... )

 {

 }

 #ifdef sgi

 # pragma reset woff 3506

 #endif

 #if !defined( BOOST_NO_SFINAE ) && !defined( BOOST_NO_TEMPLATE_PARTIAL_SPECIALIZATION ) && !defined( BOOST_NO_AUTO_PTR )

 // rvalue auto_ptr support based on a technique by Dave Abrahams

 template< class T, class R > struct sp_enable_if_auto_ptr

 {

 };

 template< class T, class R > struct sp_enable_if_auto_ptr< std::auto_ptr< T >, R >

 {

     typedef R type;

 }; 

 #endif

 } // namespace detail

 //

 //  shared_ptr

 //

 //  An enhanced relative of scoped_ptr with reference counted copy semantics.

 //  The object pointed to is deleted when the last shared_ptr pointing to it

 //  is destroyed or reset.

 //

 template<class T> class shared_ptr

 {

 private:

     // Borland 5.5.1 specific workaround

     typedef shared_ptr<T> this_type;

 public:

     typedef T element_type;

     typedef T value_type;

     typedef T * pointer;

     typedef typename boost::detail::shared_ptr_traits<T>::reference reference;

     shared_ptr(): px(0), pn() // never throws in 1.30+

     {

     }

     template<class Y>

     explicit shared_ptr( Y * p ): px( p ), pn( p ) // Y must be complete

     {

         boost::detail::sp_enable_shared_from_this( pn, p, p );

     }

     //

     // Requirements: D's copy constructor must not throw

     //

     // shared_ptr will release p by calling d(p)

     //

     template<class Y, class D> shared_ptr(Y * p, D d): px(p), pn(p, d)

     {

         boost::detail::sp_enable_shared_from_this( pn, p, p );

     }

     // As above, but with allocator. A's copy constructor shall not throw.

     template<class Y, class D, class A> shared_ptr( Y * p, D d, A a ): px( p ), pn( p, d, a )

     {

         boost::detail::sp_enable_shared_from_this( pn, p, p );

     }

 //  generated copy constructor, assignment, destructor are fine...

 //  except that Borland C++ has a bug, and g++ with -Wsynth warns

 #if defined(__BORLANDC__) || defined(__GNUC__)

     shared_ptr & operator=(shared_ptr const & r) // never throws

     {

         px = r.px;

         pn = r.pn; // shared_count::op= doesn't throw

         return *this;

     }

 #endif

     template<class Y>

     explicit shared_ptr(weak_ptr<Y> const & r): pn(r.pn) // may throw

     {

         // it is now safe to copy r.px, as pn(r.pn) did not throw

         px = r.px;

     }

     template<class Y>

     shared_ptr(shared_ptr<Y> const & r): px(r.px), pn(r.pn) // never throws

     {

     }

     template<class Y>

     shared_ptr(shared_ptr<Y> const & r, boost::detail::static_cast_tag): px(static_cast<element_type *>(r.px)), pn(r.pn)

     {

     }

     template<class Y>

     shared_ptr(shared_ptr<Y> const & r, boost::detail::const_cast_tag): px(const_cast<element_type *>(r.px)), pn(r.pn)

     {

     }

     template<class Y>

     shared_ptr(shared_ptr<Y> const & r, boost::detail::dynamic_cast_tag): px(dynamic_cast<element_type *>(r.px)), pn(r.pn)

     {

         if(px == 0) // need to allocate new counter -- the cast failed

         {

             pn = boost::detail::shared_count();

         }

     }

     template<class Y>

     shared_ptr(shared_ptr<Y> const & r, boost::detail::polymorphic_cast_tag): px(dynamic_cast<element_type *>(r.px)), pn(r.pn)

     {

         if(px == 0)

         {

             boost::throw_exception(std::bad_cast());

         }

     }

 #ifndef BOOST_NO_AUTO_PTR

     template<class Y>

     explicit shared_ptr(std::auto_ptr<Y> & r): px(r.get()), pn()

     {

         Y * tmp = r.get();

         pn = boost::detail::shared_count(r);

         boost::detail::sp_enable_shared_from_this( pn, tmp, tmp );

     }

 #if !defined( BOOST_NO_SFINAE ) && !defined( BOOST_NO_TEMPLATE_PARTIAL_SPECIALIZATION )

     template<class Ap>

     explicit shared_ptr( Ap r, typename boost::detail::sp_enable_if_auto_ptr<Ap, int>::type = 0 ): px( r.get() ), pn()

     {

         typename Ap::element_type * tmp = r.get();

         pn = boost::detail::shared_count( r );

         boost::detail::sp_enable_shared_from_this( pn, tmp, tmp );

     }

 #endif // BOOST_NO_SFINAE, BOOST_NO_TEMPLATE_PARTIAL_SPECIALIZATION

 #endif // BOOST_NO_AUTO_PTR

 #if !defined(BOOST_MSVC) || (BOOST_MSVC >= 1300)

     template<class Y>

     shared_ptr & operator=(shared_ptr<Y> const & r) // never throws

     {

         px = r.px;

         pn = r.pn; // shared_count::op= doesn't throw

         return *this;

     }

 #endif

 #ifndef BOOST_NO_AUTO_PTR

     template<class Y>

     shared_ptr & operator=( std::auto_ptr<Y> & r )

     {

         this_type(r).swap(*this);

         return *this;

     }

 #if !defined( BOOST_NO_SFINAE ) && !defined( BOOST_NO_TEMPLATE_PARTIAL_SPECIALIZATION )

     template<class Ap>

     typename boost::detail::sp_enable_if_auto_ptr< Ap, shared_ptr & >::type operator=( Ap r )

     {

         this_type( r ).swap( *this );

         return *this;

     }

 #endif // BOOST_NO_SFINAE, BOOST_NO_TEMPLATE_PARTIAL_SPECIALIZATION

 #endif // BOOST_NO_AUTO_PTR

     void reset() // never throws in 1.30+

     {

         this_type().swap(*this);

     }

     template<class Y> void reset(Y * p) // Y must be complete

     {

         BOOST_ASSERT(p == 0 || p != px); // catch self-reset errors

         this_type(p).swap(*this);

     }

     template<class Y, class D> void reset( Y * p, D d )

     {

         this_type( p, d ).swap( *this );

     }

     template<class Y, class D, class A> void reset( Y * p, D d, A a )

     {

         this_type( p, d, a ).swap( *this );

     }

     reference operator* () const // never throws

     {

         BOOST_ASSERT(px != 0);

         return *px;

     }

     T * operator-> () const // never throws

     {

         BOOST_ASSERT(px != 0);

         return px;

     }

     T * get() const // never throws

     {

         return px;

     }

     // implicit conversion to "bool"

 #if defined(__SUNPRO_CC) && BOOST_WORKAROUND(__SUNPRO_CC, <= 0x580)

     operator bool () const

     {

         return px != 0;

     }

 #elif defined( _MANAGED )

     static void unspecified_bool( this_type*** )

     {

     }

     typedef void (*unspecified_bool_type)( this_type*** );

     operator unspecified_bool_type() const // never throws

     {

         return px == 0? 0: unspecified_bool;

     }

 #elif \

     ( defined(__MWERKS__) && BOOST_WORKAROUND(__MWERKS__, < 0x3200) ) || \

     ( defined(__GNUC__) && (__GNUC__ * 100 + __GNUC_MINOR__ < 304) )

     typedef T * (this_type::*unspecified_bool_type)() const;

     operator unspecified_bool_type() const // never throws

     {

         return px == 0? 0: &this_type::get;

     }

 #else 

     typedef T * this_type::*unspecified_bool_type;

     operator unspecified_bool_type() const // never throws

     {

         return px == 0? 0: &this_type::px;

     }

 #endif

     // operator! is redundant, but some compilers need it

     bool operator! () const // never throws

     {

         return px == 0;

     }

     bool unique() const // never throws

     {

         return pn.unique();

     }

     long use_count() const // never throws

     {

         return pn.use_count();

     }

     void swap(shared_ptr<T> & other) // never throws

     {

         std::swap(px, other.px);

         pn.swap(other.pn);

     }

     template<class Y> bool _internal_less(shared_ptr<Y> const & rhs) const

     {

         return pn < rhs.pn;

     }

     void * _internal_get_deleter(std::type_info const & ti) const

     {

         return pn.get_deleter(ti);

     }

 // Tasteless as this may seem, making all members public allows member templates

 // to work in the absence of member template friends. (Matthew Langston)

 #ifndef BOOST_NO_MEMBER_TEMPLATE_FRIENDS

 private:

     template<class Y> friend class shared_ptr;

     template<class Y> friend class weak_ptr;

 #endif

     T * px;                     // contained pointer

     boost::detail::shared_count pn;    // reference counter

 };  // shared_ptr

 template<class T, class U> inline bool operator==(shared_ptr<T> const & a, shared_ptr<U> const & b)

 {

     return a.get() == b.get();

 }

 template<class T, class U> inline bool operator!=(shared_ptr<T> const & a, shared_ptr<U> const & b)

 {

     return a.get() != b.get();

 }

 #if __GNUC__ == 2 && __GNUC_MINOR__ <= 96

 // Resolve the ambiguity between our op!= and the one in rel_ops

 template<class T> inline bool operator!=(shared_ptr<T> const & a, shared_ptr<T> const & b)

 {

     return a.get() != b.get();

 }

 #endif

 template<class T, class U> inline bool operator<(shared_ptr<T> const & a, shared_ptr<U> const & b)

 {

     return a._internal_less(b);

 }

 template<class T> inline void swap(shared_ptr<T> & a, shared_ptr<T> & b)

 {

     a.swap(b);

 }

 template<class T, class U> shared_ptr<T> static_pointer_cast(shared_ptr<U> const & r)

 {

     return shared_ptr<T>(r, boost::detail::static_cast_tag());

 }

 template<class T, class U> shared_ptr<T> const_pointer_cast(shared_ptr<U> const & r)

 {

     return shared_ptr<T>(r, boost::detail::const_cast_tag());

 }

 template<class T, class U> shared_ptr<T> dynamic_pointer_cast(shared_ptr<U> const & r)

 {

     return shared_ptr<T>(r, boost::detail::dynamic_cast_tag());

 }

 // shared_*_cast names are deprecated. Use *_pointer_cast instead.

 template<class T, class U> shared_ptr<T> shared_static_cast(shared_ptr<U> const & r)

 {

     return shared_ptr<T>(r, boost::detail::static_cast_tag());

 }

 template<class T, class U> shared_ptr<T> shared_dynamic_cast(shared_ptr<U> const & r)

 {

     return shared_ptr<T>(r, boost::detail::dynamic_cast_tag());

 }

 template<class T, class U> shared_ptr<T> shared_polymorphic_cast(shared_ptr<U> const & r)

 {

     return shared_ptr<T>(r, boost::detail::polymorphic_cast_tag());

 }

 template<class T, class U> shared_ptr<T> shared_polymorphic_downcast(shared_ptr<U> const & r)

 {

     BOOST_ASSERT(dynamic_cast<T *>(r.get()) == r.get());

     return shared_static_cast<T>(r);

 }

 // get_pointer() enables boost::mem_fn to recognize shared_ptr

 template<class T> inline T * get_pointer(shared_ptr<T> const & p)

 {

     return p.get();

 }

 // operator<<

 #if defined(__GNUC__) &&  (__GNUC__ < 3)

 template<class Y> std::ostream & operator<< (std::ostream & os, shared_ptr<Y> const & p)

 {

     os << p.get();

     return os;

 }

 #else

 // in STLport's no-iostreams mode no iostream symbols can be used

 #ifndef _STLP_NO_IOSTREAMS

 # if defined(BOOST_MSVC) && BOOST_WORKAROUND(BOOST_MSVC, < 1300 && __SGI_STL_PORT)

 // MSVC6 has problems finding std::basic_ostream through the using declaration in namespace _STL

 using std::basic_ostream;

 template<class E, class T, class Y> basic_ostream<E, T> & operator<< (basic_ostream<E, T> & os, shared_ptr<Y> const & p)

 # else

 template<class E, class T, class Y> std::basic_ostream<E, T> & operator<< (std::basic_ostream<E, T> & os, shared_ptr<Y> const & p)

 # endif 

 {

     os << p.get();

     return os;

 }

 #endif // _STLP_NO_IOSTREAMS

 #endif // __GNUC__ < 3

 // get_deleter (experimental)

 #if ( defined(__GNUC__) && BOOST_WORKAROUND(__GNUC__, < 3) ) || \

     ( defined(__EDG_VERSION__) && BOOST_WORKAROUND(__EDG_VERSION__, <= 238) ) || \

     ( defined(__HP_aCC) && BOOST_WORKAROUND(__HP_aCC, <= 33500) )

 // g++ 2.9x doesn't allow static_cast<X const *>(void *)

 // apparently EDG 2.38 and HP aCC A.03.35 also don't accept it

 template<class D, class T> D * get_deleter(shared_ptr<T> const & p)

 {

     void const * q = p._internal_get_deleter(typeid(D));

     return const_cast<D *>(static_cast<D const *>(q));

 }

 #else

 template<class D, class T> D * get_deleter(shared_ptr<T> const & p)

 {

     return static_cast<D *>(p._internal_get_deleter(typeid(D)));

 }

 #endif

 } // namespace boost

 #ifdef BOOST_MSVC

 # pragma warning(pop)

 #endif    

 #endif  // #if defined(BOOST_NO_MEMBER_TEMPLATES) && !defined(BOOST_MSVC6_MEMBER_TEMPLATES)

 #endif  // #ifndef BOOST_SHARED_PTR_HPP_INCLUDED