SafePtr.cpp.

  • June 22, 2000
(B)Leading Edge
Simple Memory Management Classes
Jack Reeves
Listing 3. SafePtr.cpp.


#include "SafePtr.h"
namespace BEST {

//
// SafePtrBase
//
SafePtrBase::PtrMap    SafePtrBase::_thePtrMap;
SafePtrBase::PtrMap::iterator  SafePtrBase::_nullPtr;
bool        SafePtrBase::_initialized = init();

// static functions
bool
SafePtrBase::init()
{
  // null pointer entry - can't be removed
  _nullPtr = _thePtrMap.insert(
               PtrMap::value_type(null, Data())
             ).first;
  (*_nullPtr).second.cnt = 1;
  return true;
}

// construct
SafePtrBase::SafePtrBase(void* p)
  :  _ip(_nullPtr)
{
  if (p) {
    _ip = _thePtrMap.insert(
            PtrMap::value_type(p, Data())
          ).first;
    (*_ip).second.owned = true;
  }
  ref();
}

// Utility functions
void*
SafePtrBase::remove() const
{
  void* = (*_ip).first;
  bool owned = (*_ip).second.owned;
  _thePtrMap.erase(_ip);
  if (owned) return p;
  return null;
}

void
SafePtrBase::error() const
{
  throw std::domain_error(
    "Exception: std::domain_error(null reference)"
    );
}

} //> namespace
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