Chris@16: //////////////////////////////////////////////////////////////////////////////
Chris@16: // (c) Copyright Andreas Huber Doenni 2002-2005, Eric Niebler 2006
Chris@16: // Distributed under the Boost Software License, Version 1.0. (See accompany-
Chris@16: // ing file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
Chris@16: //////////////////////////////////////////////////////////////////////////////
Chris@16: 
Chris@16: #ifndef BOOST_XPRESSIVE_DETAIL_UTILITY_COUNTED_BASE_HPP_EAN_04_16_2006
Chris@16: #define BOOST_XPRESSIVE_DETAIL_UTILITY_COUNTED_BASE_HPP_EAN_04_16_2006
Chris@16: 
Chris@16: #include <boost/assert.hpp>
Chris@16: #include <boost/checked_delete.hpp>
Chris@16: #include <boost/detail/atomic_count.hpp>
Chris@16: 
Chris@16: namespace boost { namespace xpressive { namespace detail
Chris@16: {
Chris@16:     template<typename Derived>
Chris@16:     struct counted_base_access;
Chris@16: 
Chris@16:     //////////////////////////////////////////////////////////////////////////////
Chris@16:     // counted_base
Chris@16:     template<typename Derived>
Chris@16:     struct counted_base
Chris@16:     {
Chris@16:         long use_count() const
Chris@16:         {
Chris@16:             return this->count_;
Chris@16:         }
Chris@16: 
Chris@16:     protected:
Chris@16:         counted_base()
Chris@16:           : count_(0)
Chris@16:         {
Chris@16:         }
Chris@16: 
Chris@16:         counted_base(counted_base<Derived> const &)
Chris@16:           : count_(0)
Chris@16:         {
Chris@16:         }
Chris@16: 
Chris@16:         counted_base &operator =(counted_base<Derived> const &)
Chris@16:         {
Chris@16:             return *this;
Chris@16:         }
Chris@16: 
Chris@16:     private:
Chris@16:         friend struct counted_base_access<Derived>;
Chris@16:         mutable boost::detail::atomic_count count_;
Chris@16:     };
Chris@16: 
Chris@16:     //////////////////////////////////////////////////////////////////////////////
Chris@16:     // counted_base_access
Chris@16:     template<typename Derived>
Chris@16:     struct counted_base_access
Chris@16:     {
Chris@16:         static void add_ref(counted_base<Derived> const *that)
Chris@16:         {
Chris@16:             ++that->count_;
Chris@16:         }
Chris@16: 
Chris@16:         static void release(counted_base<Derived> const *that)
Chris@16:         {
Chris@16:             BOOST_ASSERT(0 < that->count_);
Chris@16:             if(0 == --that->count_)
Chris@16:             {
Chris@16:                 boost::checked_delete(static_cast<Derived const *>(that));
Chris@16:             }
Chris@16:         }
Chris@16:     };
Chris@16: 
Chris@16:     template<typename Derived>
Chris@16:     inline void intrusive_ptr_add_ref(counted_base<Derived> const *that)
Chris@16:     {
Chris@16:         counted_base_access<Derived>::add_ref(that);
Chris@16:     }
Chris@16: 
Chris@16:     template<typename Derived>
Chris@16:     inline void intrusive_ptr_release(counted_base<Derived> const *that)
Chris@16:     {
Chris@16:         counted_base_access<Derived>::release(that);
Chris@16:     }
Chris@16: 
Chris@16: }}} // namespace boost::xpressive::detail
Chris@16: 
Chris@16: #endif