boost/intrusive_ptr.hpp
#ifndef BOOST_INTRUSIVE_PTR_HPP_INCLUDED
#define BOOST_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 <functional> // for std::less
#include <iosfwd> // for std::basic_ostream
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(): p_(0)
{
}
intrusive_ptr(T * p, bool add_ref = true): p_(p)
{
if(p_ != 0 && add_ref) intrusive_ptr_add_ref(p_);
}
#if !defined(BOOST_NO_MEMBER_TEMPLATES) || defined(BOOST_MSVC6_MEMBER_TEMPLATES)
template<class U> intrusive_ptr(intrusive_ptr<U> const & rhs): p_(rhs.get())
{
if(p_ != 0) intrusive_ptr_add_ref(p_);
}
#endif
intrusive_ptr(intrusive_ptr const & rhs): p_(rhs.p_)
{
if(p_ != 0) intrusive_ptr_add_ref(p_);
}
~intrusive_ptr()
{
if(p_ != 0) intrusive_ptr_release(p_);
}
#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( T * rhs )
{
this_type( rhs ).swap( *this );
}
T * get() const
{
return p_;
}
T & operator*() const
{
BOOST_ASSERT( p_ != 0 );
return *p_;
}
T * operator->() const
{
BOOST_ASSERT( p_ != 0 );
return p_;
}
#if defined(__SUNPRO_CC) && BOOST_WORKAROUND(__SUNPRO_CC, <= 0x530)
operator bool () const
{
return p_ != 0;
}
#elif defined(__MWERKS__) && BOOST_WORKAROUND(__MWERKS__, BOOST_TESTED_AT(0x3003))
typedef T * (this_type::*unspecified_bool_type)() const;
operator unspecified_bool_type() const // never throws
{
return p_ == 0? 0: &this_type::get;
}
#else
typedef T * this_type::*unspecified_bool_type;
operator unspecified_bool_type () const
{
return p_ == 0? 0: &this_type::p_;
}
#endif
// operator! is a Borland-specific workaround
bool operator! () const
{
return p_ == 0;
}
void swap(intrusive_ptr & rhs)
{
T * tmp = p_;
p_ = rhs.p_;
rhs.p_ = tmp;
}
private:
T * p_;
};
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(__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
} // namespace boost
#ifdef BOOST_MSVC
# pragma warning(pop)
#endif
#endif // #ifndef BOOST_INTRUSIVE_PTR_HPP_INCLUDED