boost/smart_ptr/intrusive_ptr.hpp
#ifndef BOOST_SMART_PTR_INTRUSIVE_PTR_HPP_INCLUDED
#define BOOST_SMART_PTR_INTRUSIVE_PTR_HPP_INCLUDED
//
// intrusive_ptr.hpp
//
// Copyright (c) 2001, 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)
//
// See http://www.boost.org/libs/smart_ptr/intrusive_ptr.html for documentation.
//
#include <boost/config.hpp>
#ifdef BOOST_MSVC // moved here to work around VC++ compiler crash
# pragma warning(push)
# pragma warning(disable:4284) // odd return type for operator->
#endif
#include <boost/assert.hpp>
#include <boost/detail/workaround.hpp>
#include <boost/smart_ptr/detail/sp_convertible.hpp>
#include <boost/config/no_tr1/functional.hpp> // for std::less
#if !defined(BOOST_NO_IOSTREAM)
#if !defined(BOOST_NO_IOSFWD)
#include <iosfwd> // for std::basic_ostream
#else
#include <ostream>
#endif
#endif
namespace boost
{
//
// intrusive_ptr
//
// A smart pointer that uses intrusive reference counting.
//
// Relies on unqualified calls to
//
// void intrusive_ptr_add_ref(T * p);
// void intrusive_ptr_release(T * p);
//
// (p != 0)
//
// The object is responsible for destroying itself.
//
template<class T> class intrusive_ptr
{
private:
typedef intrusive_ptr this_type;
public:
typedef T element_type;
intrusive_ptr(): px( 0 )
{
}
intrusive_ptr( T * p, bool add_ref = true ): px( p )
{
if( px != 0 && add_ref ) intrusive_ptr_add_ref( px );
}
#if !defined(BOOST_NO_MEMBER_TEMPLATES) || defined(BOOST_MSVC6_MEMBER_TEMPLATES)
template<class U>
#if !defined( BOOST_SP_NO_SP_CONVERTIBLE )
intrusive_ptr( intrusive_ptr<U> const & rhs, typename detail::sp_enable_if_convertible<U,T>::type = detail::sp_empty() )
#else
intrusive_ptr( intrusive_ptr<U> const & rhs )
#endif
: px( rhs.get() )
{
if( px != 0 ) intrusive_ptr_add_ref( px );
}
#endif
intrusive_ptr(intrusive_ptr const & rhs): px( rhs.px )
{
if( px != 0 ) intrusive_ptr_add_ref( px );
}
~intrusive_ptr()
{
if( px != 0 ) intrusive_ptr_release( px );
}
#if !defined(BOOST_NO_MEMBER_TEMPLATES) || defined(BOOST_MSVC6_MEMBER_TEMPLATES)
template<class U> intrusive_ptr & operator=(intrusive_ptr<U> const & rhs)
{
this_type(rhs).swap(*this);
return *this;
}
#endif
intrusive_ptr & operator=(intrusive_ptr const & rhs)
{
this_type(rhs).swap(*this);
return *this;
}
intrusive_ptr & operator=(T * rhs)
{
this_type(rhs).swap(*this);
return *this;
}
void reset()
{
this_type().swap( *this );
}
void reset( T * rhs )
{
this_type( rhs ).swap( *this );
}
T * get() const
{
return px;
}
T & operator*() const
{
BOOST_ASSERT( px != 0 );
return *px;
}
T * operator->() const
{
BOOST_ASSERT( px != 0 );
return px;
}
// implicit conversion to "bool"
#include <boost/smart_ptr/detail/operator_bool.hpp>
void swap(intrusive_ptr & rhs)
{
T * tmp = px;
px = rhs.px;
rhs.px = tmp;
}
private:
T * px;
};
template<class T, class U> inline bool operator==(intrusive_ptr<T> const & a, intrusive_ptr<U> const & b)
{
return a.get() == b.get();
}
template<class T, class U> inline bool operator!=(intrusive_ptr<T> const & a, intrusive_ptr<U> const & b)
{
return a.get() != b.get();
}
template<class T, class U> inline bool operator==(intrusive_ptr<T> const & a, U * b)
{
return a.get() == b;
}
template<class T, class U> inline bool operator!=(intrusive_ptr<T> const & a, U * b)
{
return a.get() != b;
}
template<class T, class U> inline bool operator==(T * a, intrusive_ptr<U> const & b)
{
return a == b.get();
}
template<class T, class U> inline bool operator!=(T * a, intrusive_ptr<U> const & b)
{
return a != 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!=(intrusive_ptr<T> const & a, intrusive_ptr<T> const & b)
{
return a.get() != b.get();
}
#endif
template<class T> inline bool operator<(intrusive_ptr<T> const & a, intrusive_ptr<T> const & b)
{
return std::less<T *>()(a.get(), b.get());
}
template<class T> void swap(intrusive_ptr<T> & lhs, intrusive_ptr<T> & rhs)
{
lhs.swap(rhs);
}
// mem_fn support
template<class T> T * get_pointer(intrusive_ptr<T> const & p)
{
return p.get();
}
template<class T, class U> intrusive_ptr<T> static_pointer_cast(intrusive_ptr<U> const & p)
{
return static_cast<T *>(p.get());
}
template<class T, class U> intrusive_ptr<T> const_pointer_cast(intrusive_ptr<U> const & p)
{
return const_cast<T *>(p.get());
}
template<class T, class U> intrusive_ptr<T> dynamic_pointer_cast(intrusive_ptr<U> const & p)
{
return dynamic_cast<T *>(p.get());
}
// operator<<
#if !defined(BOOST_NO_IOSTREAM)
#if defined(BOOST_NO_TEMPLATED_IOSTREAMS) || ( defined(__GNUC__) && (__GNUC__ < 3) )
template<class Y> std::ostream & operator<< (std::ostream & os, intrusive_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, intrusive_ptr<Y> const & p)
# else
template<class E, class T, class Y> std::basic_ostream<E, T> & operator<< (std::basic_ostream<E, T> & os, intrusive_ptr<Y> const & p)
# endif
{
os << p.get();
return os;
}
#endif // _STLP_NO_IOSTREAMS
#endif // __GNUC__ < 3
#endif // !defined(BOOST_NO_IOSTREAM)
} // namespace boost
#ifdef BOOST_MSVC
# pragma warning(pop)
#endif
#endif // #ifndef BOOST_SMART_PTR_INTRUSIVE_PTR_HPP_INCLUDED