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#ifndef BOOST_SMART_PTR_ENABLE_SHARED_FROM_THIS_HPP_INCLUDED
#define BOOST_SMART_PTR_ENABLE_SHARED_FROM_THIS_HPP_INCLUDED
//
// enable_shared_from_this.hpp
//
// Copyright 2002, 2009 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
//
// http://www.boost.org/libs/smart_ptr/enable_shared_from_this.html
//
#include <boost/smart_ptr/weak_ptr.hpp>
#include <boost/smart_ptr/shared_ptr.hpp>
#include <boost/smart_ptr/detail/sp_noexcept.hpp>
#include <boost/assert.hpp>
#include <boost/config.hpp>
namespace boost
{
template<class T> class enable_shared_from_this
{
protected:
enable_shared_from_this() BOOST_SP_NOEXCEPT
{
}
enable_shared_from_this(enable_shared_from_this const &) BOOST_SP_NOEXCEPT
{
}
enable_shared_from_this & operator=(enable_shared_from_this const &) BOOST_SP_NOEXCEPT
{
return *this;
}
~enable_shared_from_this() BOOST_SP_NOEXCEPT // ~weak_ptr<T> newer throws, so this call also must not throw
{
}
public:
shared_ptr<T> shared_from_this()
{
shared_ptr<T> p( weak_this_ );
BOOST_ASSERT( p.get() == this );
return p;
}
shared_ptr<T const> shared_from_this() const
{
shared_ptr<T const> p( weak_this_ );
BOOST_ASSERT( p.get() == this );
return p;
}
weak_ptr<T> weak_from_this() BOOST_NOEXCEPT
{
return weak_this_;
}
weak_ptr<T const> weak_from_this() const BOOST_NOEXCEPT
{
return weak_this_;
}
public: // actually private, but avoids compiler template friendship issues
// Note: invoked automatically by shared_ptr; do not call
template<class X, class Y> void _internal_accept_owner( shared_ptr<X> const * ppx, Y * py ) const
{
if( weak_this_.expired() )
{
weak_this_ = shared_ptr<T>( *ppx, py );
}
}
private:
mutable weak_ptr<T> weak_this_;
};
} // namespace boost
#endif // #ifndef BOOST_SMART_PTR_ENABLE_SHARED_FROM_THIS_HPP_INCLUDED
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