OW_ReferenceBase.hpp

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#ifndef OW_REFERENCE_BASE_HPP_INCLUDE_GUARD_
#define OW_REFERENCE_BASE_HPP_INCLUDE_GUARD_
#include "OW_config.h"
#include "OW_RefCount.hpp"

// The classes and functions defined in this file are not meant for general
// use, they are internal implementation details.  They may change at any time.

namespace OW_NAMESPACE
{

template<class T>
inline void RefSwap(T& x, T&y)
{
   T t = x;
   x = y;
   y = t;
}
// This class contains the non-templated code for Reference, to help 
// minimize code bloat.
class OW_COMMON_API ReferenceBase
{
#if !defined(__GNUC__) || __GNUC__ > 2 // because of a gcc 2.95 ICE
protected:
#else
public:
#endif
   ReferenceBase()
      : m_pRefCount(new RefCount) {}
   ReferenceBase(const ReferenceBase& arg)
      : m_pRefCount(0)
   {
      m_pRefCount = arg.m_pRefCount;
      m_pRefCount->inc();
   }
   void incRef()
   {
      m_pRefCount->inc();
   }
   
   bool decRef()
   {
      if (m_pRefCount->decAndTest())
      {
         delete m_pRefCount;
         return true;
      }
      return false;
   }
   void swap(ReferenceBase& arg)
   {
      RefSwap(m_pRefCount, arg.m_pRefCount);
   }
   void useRefCountOf(const ReferenceBase& arg)
   {
      decRef();
      m_pRefCount = arg.m_pRefCount;
      incRef();
   }
   
#ifdef OW_CHECK_NULL_REFERENCES
   static void throwNULLException();
   static void checkNull(const void *p)
   {
      if (p == 0)
      {
         throwNULLException();
      }
   }
#endif

#if !defined(__GNUC__) || __GNUC__ > 2 // because of a gcc 2.95 ICE
protected:
#else
public:
#endif
   RefCount* volatile m_pRefCount;
};

} // end namespace OW_NAMESPACE

#endif

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