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 //////////////////////////////////////////////////////////////////////////////
 //
 // This file is the adaptation for Interprocess of boost/shared_ptr.hpp
 //
 // (C) Copyright Greg Colvin and Beman Dawes 1998, 1999.
 // (C) Copyright Peter Dimov 2001, 2002, 2003
 // (C) Copyright Ion Gaztanaga 2006-2012.
 // 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/interprocess for documentation.
 //
 //////////////////////////////////////////////////////////////////////////////
 
 #ifndef BOOST_INTERPROCESS_SHARED_PTR_HPP_INCLUDED
 #define BOOST_INTERPROCESS_SHARED_PTR_HPP_INCLUDED
 
 #ifndef BOOST_CONFIG_HPP
 #  include <boost/config.hpp>
 #endif
 #
 #if defined(BOOST_HAS_PRAGMA_ONCE)
 #  pragma once
 #endif
 
 #include <boost/interprocess/detail/config_begin.hpp>
 #include <boost/interprocess/detail/workaround.hpp>
 
 #include <boost/interprocess/detail/utilities.hpp>
 #include <boost/interprocess/detail/cast_tags.hpp>
 #include <boost/assert.hpp>
 #include <boost/interprocess/smart_ptr/detail/shared_count.hpp>
 #include <boost/interprocess/detail/mpl.hpp>
 #include <boost/interprocess/detail/nothrow.hpp>
 #include <boost/move/utility_core.hpp>
 #include <boost/interprocess/detail/type_traits.hpp>
 #include <boost/interprocess/allocators/allocator.hpp>
 #include <boost/interprocess/smart_ptr/deleter.hpp>
 #include <boost/intrusive/pointer_traits.hpp>
 
 #include <iosfwd> // for std::basic_ostream
 
 //!\file
 //!Describes the smart pointer shared_ptr
 
 namespace boost{
 namespace interprocess{
 
 template<class T, class VoidAllocator, class Deleter> class weak_ptr;
 template<class T, class VoidAllocator, class Deleter> class enable_shared_from_this;
 
 namespace ipcdetail{
 
 template<class T, class VoidAllocator, class Deleter>
 inline void sp_enable_shared_from_this
   (shared_count<T, VoidAllocator, Deleter> const & pn
   ,enable_shared_from_this<T, VoidAllocator, Deleter> const*pe
   ,T *ptr)
 
 {
    (void)ptr;
    if(pe != 0){
       pe->_internal_weak_this._internal_assign(pn);
    }
 }
 
 template<class T, class VoidAllocator, class Deleter>
 inline void sp_enable_shared_from_this(shared_count<T, VoidAllocator, Deleter> const &, ...)
 {}
 
 } // namespace ipcdetail
 
 //!shared_ptr stores a pointer to a dynamically allocated object.
 //!The object pointed to is guaranteed to be deleted when the last shared_ptr pointing to
 //!it is destroyed or reset.
 //!
 //!shared_ptr is parameterized on
 //!T (the type of the object pointed to), VoidAllocator (the void allocator to be used
 //!to allocate the auxiliary data) and Deleter (the deleter whose
 //!operator() will be used to delete the object.
 //!
 //!The internal pointer will be of the same pointer type as typename
 //!VoidAllocator::pointer type (that is, if typename VoidAllocator::pointer is
 //!offset_ptr<void>, the internal pointer will be offset_ptr<T>).
 //!
 //!Because the implementation uses reference counting, cycles of shared_ptr
 //!instances will not be reclaimed. For example, if main() holds a
 //!shared_ptr to A, which directly or indirectly holds a shared_ptr back
 //!to A, A's use count will be 2. Destruction of the original shared_ptr
 //!will leave A dangling with a use count of 1.
 //!Use weak_ptr to "break cycles."
 template<class T, class VoidAllocator, class Deleter>
 class shared_ptr
 {
    #if !defined(BOOST_INTERPROCESS_DOXYGEN_INVOKED)
    private:
    typedef shared_ptr<T, VoidAllocator, Deleter> this_type;
    #endif   //#ifndef BOOST_INTERPROCESS_DOXYGEN_INVOKED
 
    public:
 
    typedef T                                                   element_type;
    typedef T                                                   value_type;
    typedef typename boost::container::
       allocator_traits<VoidAllocator>::pointer                 void_ptr;
    typedef typename boost::intrusive::
       pointer_traits<void_ptr>::template
          rebind_pointer<T>::type                               pointer;
    typedef typename ipcdetail::add_reference
                      <value_type>::type                        reference;
    typedef typename ipcdetail::add_reference
                      <const value_type>::type                  const_reference;
    typedef typename boost::intrusive::
       pointer_traits<void_ptr>::template
          rebind_pointer<const Deleter>::type                               const_deleter_pointer;
    typedef typename boost::intrusive::
       pointer_traits<void_ptr>::template
          rebind_pointer<const VoidAllocator>::type                         const_allocator_pointer;
 
    BOOST_COPYABLE_AND_MOVABLE(shared_ptr)
    public:
 
    //!Constructs an empty shared_ptr.
    //!Use_count() == 0 && get()== 0.
    shared_ptr()
       :  m_pn() // never throws
    {}
 
    //!Constructs a shared_ptr that owns the pointer p. Auxiliary data will be allocated
    //!with a copy of a and the object will be deleted with a copy of d.
    //!Requirements: Deleter and A's copy constructor must not throw.
    explicit shared_ptr(const pointer&p, const VoidAllocator &a = VoidAllocator(), const Deleter &d = Deleter())
       :  m_pn(p, a, d)
    {
       //Check that the pointer passed is of the same type that
       //the pointer the allocator defines or it's a raw pointer
       typedef typename boost::intrusive::
          pointer_traits<pointer>::template
             rebind_pointer<T>::type                         ParameterPointer;
 
       BOOST_INTERPROCESS_STATIC_ASSERT((ipcdetail::is_same<pointer, ParameterPointer>::value) ||
                           (ipcdetail::is_pointer<pointer>::value));
       ipcdetail::sp_enable_shared_from_this<T, VoidAllocator, Deleter>( m_pn, ipcdetail::to_raw_pointer(p), ipcdetail::to_raw_pointer(p) );
    }
 
    //!Copy constructs a shared_ptr. If r is empty, constructs an empty shared_ptr. Otherwise, constructs
    //!a shared_ptr that shares ownership with r. Never throws.
    shared_ptr(const shared_ptr &r)
       :  m_pn(r.m_pn) // never throws
    {}
 
    //!Constructs a shared_ptr that shares ownership with other and stores p.
    //!Postconditions: get() == p && use_count() == r.use_count().
    //!Throws: nothing.
    shared_ptr(const shared_ptr &other, const pointer &p)
       :  m_pn(other.m_pn, p)
    {}
 
    //!If r is empty, constructs an empty shared_ptr. Otherwise, constructs
    //!a shared_ptr that shares ownership with r. Never throws.
    template<class Y>
    shared_ptr(shared_ptr<Y, VoidAllocator, Deleter> const & r)
       :  m_pn(r.m_pn) // never throws
    {}
 
    //!Constructs a shared_ptr that shares ownership with r and stores
    //!a copy of the pointer stored in r.
    template<class Y>
    explicit shared_ptr(weak_ptr<Y, VoidAllocator, Deleter> const & r)
       :  m_pn(r.m_pn) // may throw
    {}
 
    //!Move-Constructs a shared_ptr that takes ownership of other resource and
    //!other is put in default-constructed state.
    //!Throws: nothing.
    explicit shared_ptr(BOOST_RV_REF(shared_ptr) other)
       :  m_pn()
    {  this->swap(other);   }
 
    #if !defined(BOOST_INTERPROCESS_DOXYGEN_INVOKED)
    template<class Y>
    shared_ptr(shared_ptr<Y, VoidAllocator, Deleter> const & r, ipcdetail::static_cast_tag)
       :  m_pn( pointer(static_cast<T*>(ipcdetail::to_raw_pointer(r.m_pn.to_raw_pointer())))
              , r.m_pn)
    {}
 
    template<class Y>
    shared_ptr(shared_ptr<Y, VoidAllocator, Deleter> const & r, ipcdetail::const_cast_tag)
       :  m_pn( pointer(const_cast<T*>(ipcdetail::to_raw_pointer(r.m_pn.to_raw_pointer())))
              , r.m_pn)
    {}
 
    template<class Y>
    shared_ptr(shared_ptr<Y, VoidAllocator, Deleter> const & r, ipcdetail::dynamic_cast_tag)
       :  m_pn( pointer(dynamic_cast<T*>(ipcdetail::to_raw_pointer(r.m_pn.to_raw_pointer())))
              , r.m_pn)
    {
       if(!m_pn.to_raw_pointer()){ // need to allocate new counter -- the cast failed
          m_pn = ipcdetail::shared_count<T, VoidAllocator, Deleter>();
       }
    }
    #endif   //#ifndef BOOST_INTERPROCESS_DOXYGEN_INVOKED
 
    //!Equivalent to shared_ptr(r).swap(*this).
    //!Never throws
    template<class Y>
    shared_ptr & operator=(shared_ptr<Y, VoidAllocator, Deleter> const & r)
    {
       m_pn = r.m_pn; // shared_count::op= doesn't throw
       return *this;
    }
 
    //!Equivalent to shared_ptr(r).swap(*this).
    //!Never throws
    shared_ptr & operator=(BOOST_COPY_ASSIGN_REF(shared_ptr) r)
    {
       m_pn = r.m_pn; // shared_count::op= doesn't throw
       return *this;
    }
 
    //!Move-assignment. Equivalent to shared_ptr(other).swap(*this).
    //!Never throws
    shared_ptr & operator=(BOOST_RV_REF(shared_ptr) other) // never throws
    {
       this_type(other).swap(*this);
       return *this;
    }
 
    //!This is equivalent to:
    //!this_type().swap(*this);
    void reset()
    {
       this_type().swap(*this);
    }
 
    //!This is equivalent to:
    //!this_type(p, a, d).swap(*this);
    template<class Pointer>
    void reset(const Pointer &p, const VoidAllocator &a = VoidAllocator(), const Deleter &d = Deleter())
    {
       //Check that the pointer passed is of the same type that
       //the pointer the allocator defines or it's a raw pointer
       typedef typename boost::intrusive::
          pointer_traits<Pointer>::template
             rebind_pointer<T>::type                         ParameterPointer;
       BOOST_INTERPROCESS_STATIC_ASSERT((ipcdetail::is_same<pointer, ParameterPointer>::value) ||
                           (ipcdetail::is_pointer<Pointer>::value));
       this_type(p, a, d).swap(*this);
    }
 
    template<class Y>
    void reset(shared_ptr<Y, VoidAllocator, Deleter> const & r, const pointer &p)
    {
       this_type(r, p).swap(*this);
    }
 
    //!Returns a reference to the
    //!pointed type
    reference operator* () const // never throws
    {  BOOST_ASSERT(m_pn.to_raw_pointer() != 0);  return *m_pn.to_raw_pointer(); }
 
    //!Returns the pointer pointing
    //!to the owned object
    pointer operator-> () const // never throws
    {  BOOST_ASSERT(m_pn.to_raw_pointer() != 0);  return m_pn.to_raw_pointer();  }
 
    //!Returns the pointer pointing
    //!to the owned object
    pointer get() const  // never throws
    {  return m_pn.to_raw_pointer();  }
 
    #if !defined(BOOST_INTERPROCESS_DOXYGEN_INVOKED)
    // implicit conversion to "bool"
    void unspecified_bool_type_func() const {}
    typedef void (this_type::*unspecified_bool_type)() const;
 
    operator unspecified_bool_type() const // never throws
    {  return !m_pn.to_raw_pointer() ? 0 : &this_type::unspecified_bool_type_func;  }
    #endif   //#ifndef BOOST_INTERPROCESS_DOXYGEN_INVOKED
 
    //!Not operator.
    //!Returns true if this->get() != 0, false otherwise
    bool operator! () const // never throws
    {  return !m_pn.to_raw_pointer();   }
 
    //!Returns use_count() == 1.
    //!unique() might be faster than use_count()
    bool unique() const // never throws
    {  return m_pn.unique();  }
 
    //!Returns the number of shared_ptr objects, *this included,
    //!that share ownership with *this, or an unspecified nonnegative
    //!value when *this is empty.
    //!use_count() is not necessarily efficient. Use only for
    //!debugging and testing purposes, not for production code.
    long use_count() const // never throws
    {  return m_pn.use_count();  }
 
    //!Exchanges the contents of the two
    //!smart pointers.
    void swap(shared_ptr<T, VoidAllocator, Deleter> & other) // never throws
    {  m_pn.swap(other.m_pn);   }
 
    #if !defined(BOOST_INTERPROCESS_DOXYGEN_INVOKED)
 
    template<class T2, class A2, class Deleter2>
    bool _internal_less(shared_ptr<T2, A2, Deleter2> const & rhs) const
    {  return m_pn < rhs.m_pn;  }
 
    const_deleter_pointer get_deleter() const
    {  return m_pn.get_deleter(); }
 
 //   const_allocator_pointer get_allocator() const
 //   {  return m_pn.get_allocator(); }
 
    private:
 
    template<class T2, class A2, class Deleter2> friend class shared_ptr;
    template<class T2, class A2, class Deleter2> friend class weak_ptr;
 
    ipcdetail::shared_count<T, VoidAllocator, Deleter>   m_pn;    // reference counter
    #endif   //#ifndef BOOST_INTERPROCESS_DOXYGEN_INVOKED
 };  // shared_ptr
 
 template<class T, class VoidAllocator, class Deleter, class U, class VoidAllocator2, class Deleter2> inline
 bool operator==(shared_ptr<T, VoidAllocator, Deleter> const & a, shared_ptr<U, VoidAllocator2, Deleter2> const & b)
 {  return a.get() == b.get(); }
 
 template<class T, class VoidAllocator, class Deleter, class U, class VoidAllocator2, class Deleter2> inline
 bool operator!=(shared_ptr<T, VoidAllocator, Deleter> const & a, shared_ptr<U, VoidAllocator2, Deleter2> const & b)
 {  return a.get() != b.get(); }
 
 template<class T, class VoidAllocator, class Deleter, class U, class VoidAllocator2, class Deleter2> inline
 bool operator<(shared_ptr<T, VoidAllocator, Deleter> const & a, shared_ptr<U, VoidAllocator2, Deleter2> const & b)
 {  return a._internal_less(b);   }
 
 template<class T, class VoidAllocator, class Deleter> inline
 void swap(shared_ptr<T, VoidAllocator, Deleter> & a, shared_ptr<T, VoidAllocator, Deleter> & b)
 {  a.swap(b);  }
 
 template<class T, class VoidAllocator, class Deleter, class U> inline
 shared_ptr<T, VoidAllocator, Deleter> static_pointer_cast(shared_ptr<U, VoidAllocator, Deleter> const & r)
 {  return shared_ptr<T, VoidAllocator, Deleter>(r, ipcdetail::static_cast_tag());   }
 
 template<class T, class VoidAllocator, class Deleter, class U> inline
 shared_ptr<T, VoidAllocator, Deleter> const_pointer_cast(shared_ptr<U, VoidAllocator, Deleter> const & r)
 {  return shared_ptr<T, VoidAllocator, Deleter>(r, ipcdetail::const_cast_tag()); }
 
 template<class T, class VoidAllocator, class Deleter, class U> inline
 shared_ptr<T, VoidAllocator, Deleter> dynamic_pointer_cast(shared_ptr<U, VoidAllocator, Deleter> const & r)
 {  return shared_ptr<T, VoidAllocator, Deleter>(r, ipcdetail::dynamic_cast_tag());  }
 
 // to_raw_pointer() enables boost::mem_fn to recognize shared_ptr
 template<class T, class VoidAllocator, class Deleter> inline
 T * to_raw_pointer(shared_ptr<T, VoidAllocator, Deleter> const & p)
 {  return p.get();   }
 
 // operator<<
 template<class E, class T, class Y, class VoidAllocator, class Deleter> inline
 std::basic_ostream<E, T> & operator<<
    (std::basic_ostream<E, T> & os, shared_ptr<Y, VoidAllocator, Deleter> const & p)
 {  os << p.get();   return os;   }
 
 //!Returns the type of a shared pointer
 //!of type T with the allocator boost::interprocess::allocator allocator
 //!and boost::interprocess::deleter deleter
 //!that can be constructed in the given managed segment type.
 template<class T, class ManagedMemory>
 struct managed_shared_ptr
 {
    typedef typename ManagedMemory::template allocator<void>::type void_allocator;
    typedef typename ManagedMemory::template deleter<T>::type      deleter;
    typedef shared_ptr< T, void_allocator, deleter>                type;
 };
 
 //!Returns an instance of a shared pointer constructed
 //!with the default allocator and deleter from a pointer
 //!of type T that has been allocated in the passed managed segment
 template<class T, class ManagedMemory>
 inline typename managed_shared_ptr<T, ManagedMemory>::type
    make_managed_shared_ptr(T *constructed_object, ManagedMemory &managed_memory)
 {
    return typename managed_shared_ptr<T, ManagedMemory>::type
    ( constructed_object
    , managed_memory.template get_allocator<void>()
    , managed_memory.template get_deleter<T>()
    );
 }
 
 //!Returns an instance of a shared pointer constructed
 //!with the default allocator and deleter from a pointer
 //!of type T that has been allocated in the passed managed segment.
 //!Does not throw, return null shared pointer in error.
 template<class T, class ManagedMemory>
 inline typename managed_shared_ptr<T, ManagedMemory>::type
    make_managed_shared_ptr(T *constructed_object, ManagedMemory &managed_memory, const std::nothrow_t &)
 {
    BOOST_INTERPROCESS_TRY{
       return typename managed_shared_ptr<T, ManagedMemory>::type
       ( constructed_object
       , managed_memory.template get_allocator<void>()
       , managed_memory.template get_deleter<T>()
       );
    }
    BOOST_INTERPROCESS_CATCH(...){
       return typename managed_shared_ptr<T, ManagedMemory>::type();
    } BOOST_INTERPROCESS_CATCH_END
 }
 
 
 } // namespace interprocess
 
 #if !defined(BOOST_INTERPROCESS_DOXYGEN_INVOKED)
 
 #if defined(_MSC_VER) && (_MSC_VER < 1400)
 // to_raw_pointer() enables boost::mem_fn to recognize shared_ptr
 template<class T, class VoidAllocator, class Deleter> inline
 T * to_raw_pointer(boost::interprocess::shared_ptr<T, VoidAllocator, Deleter> const & p)
 {  return p.get();   }
 #endif
 
 #endif   //#ifndef BOOST_INTERPROCESS_DOXYGEN_INVOKED
 
 } // namespace boost
 
 #include <boost/interprocess/detail/config_end.hpp>
 
 #endif  // #ifndef BOOST_INTERPROCESS_SHARED_PTR_HPP_INCLUDED

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