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Sync enable_shared_from_this.hpp and shared_ptr.hpp with release.

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[SVN r51485]
This commit is contained in:
Peter Dimov
2009-02-28 20:02:12 +00:00
parent c40b306647
commit 13f91c15f0
2 changed files with 71 additions and 201 deletions
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include/boost/enable_shared_from_this.hpp
+17 -78
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@@ -13,23 +13,15 @@
// http://www.boost.org/libs/smart_ptr/enable_shared_from_this.html
//
#include <boost/config.hpp>
#include <boost/weak_ptr.hpp>
#include <boost/shared_ptr.hpp>
#include <boost/assert.hpp>
#include <boost/detail/workaround.hpp>
#include <boost/config.hpp>
namespace boost
{
#if !defined( BOOST_NO_MEMBER_TEMPLATE_FRIENDS )
template< class T > class enable_shared_from_this;
template< class T, class Y > void sp_accept_owner( shared_ptr<Y> * ptr, enable_shared_from_this<T> const * pe );
template< class T, class Y > void sp_accept_owner( shared_ptr<Y> * ptr, enable_shared_from_this<T> const * pe, void * /*pd*/ );
#endif
template< class T > class enable_shared_from_this
template<class T> class enable_shared_from_this
{
protected:
@@ -46,89 +38,36 @@ protected:
return *this;
}
// virtual destructor because we need a vtable for dynamic_cast from base to derived to work
virtual ~enable_shared_from_this()
~enable_shared_from_this()
{
BOOST_ASSERT( _shared_count.use_count() <= 1 ); // make sure no dangling shared_ptr objects exist
}
public:
shared_ptr<T> shared_from_this()
{
init_weak_once();
T * p = dynamic_cast<T *>( this );
return shared_ptr<T>( detail::shared_count( _weak_count ), p );
shared_ptr<T> p(_internal_weak_this);
BOOST_ASSERT(p.get() == this);
return p;
}
shared_ptr<T const> shared_from_this() const
{
init_weak_once();
T const * p = dynamic_cast<T const *>( this );
return shared_ptr<T const>( detail::shared_count( _weak_count ), p );
shared_ptr<T const> p(_internal_weak_this);
BOOST_ASSERT(p.get() == this);
return p;
}
private:
// Note: No, you don't need to initialize _internal_weak_this
//
// Please read the documentation, not the code
//
// http://www.boost.org/libs/smart_ptr/enable_shared_from_this.html
mutable detail::weak_count _weak_count;
mutable detail::shared_count _shared_count;
void init_weak_once() const
{
if( _weak_count.empty() )
{
detail::shared_count( (void*)0, detail::sp_deleter_wrapper() ).swap( _shared_count );
_weak_count = _shared_count;
}
}
#if !defined( BOOST_NO_MEMBER_TEMPLATE_FRIENDS )
template< class U, class Y > friend void sp_accept_owner( shared_ptr<Y> * ptr, enable_shared_from_this<U> const * pe );
template< class U, class Y > friend void sp_accept_owner( shared_ptr<Y> * ptr, enable_shared_from_this<U> const * pe, void * /*pd*/ );
#else
public:
#endif
template<typename U>
void sp_accept_owner( shared_ptr<U> & owner ) const
{
if( _weak_count.use_count() == 0 )
{
_weak_count = owner.get_shared_count();
}
else if( !_shared_count.empty() )
{
BOOST_ASSERT( owner.unique() ); // no weak_ptrs to owner should exist either, but there's no way to check that
detail::sp_deleter_wrapper * pd = detail::basic_get_deleter<detail::sp_deleter_wrapper>( _shared_count );
BOOST_ASSERT( pd != 0 );
pd->set_deleter( owner.get_shared_count() );
owner.reset( _shared_count, owner.get() );
detail::shared_count().swap( _shared_count );
}
}
typedef T _internal_element_type; // for bcc 5.5.1
mutable weak_ptr<_internal_element_type> _internal_weak_this;
};
template< class T, class Y > inline void sp_accept_owner( shared_ptr<Y> * ptr, enable_shared_from_this<T> const * pe )
{
if( pe != 0 )
{
pe->sp_accept_owner( *ptr );
}
}
template< class T, class Y > inline void sp_accept_owner( shared_ptr<Y> * ptr, enable_shared_from_this<T> const * pe, void * /*pd*/ )
{
if( pe != 0 )
{
pe->sp_accept_owner( *ptr );
}
}
} // namespace boost
#endif // #ifndef BOOST_ENABLE_SHARED_FROM_THIS_HPP_INCLUDED