Figure 2: Definition and implementation of the ErrorCode class

// ErrorCodes.h

enum ErrorCodeValue { Success, MyError1, MyError2, MyError3 };

class ErrorCode
{
private:
   ErrorCodeValue enValue_;
   bool * PboResp_;

public:
   ErrorCode();
   ErrorCode(const ErrorCode& _ref);
   ErrorCode(ErrorCodeValue _val);
   virtual ~ErrorCode();

   ErrorCode& operator = (const ErrorCode& _ref);

   bool operator != (const ErrorCode& _ref) const;
   bool operator == (const ErrorCode& _ref) const
      { return !(*this != _ref); };
};

// ErrorCodes.cpp
#include "ErrorCodes.h"
#include <iostream.h>

ErrorCode::ErrorCode() : enValue_(Success),
   PboResp_(new bool(false))
{
}

ErrorCode::ErrorCode(const ErrorCode& _ref) :
   enValue_(_ref.enValue_), PboResp_(new bool(true))
{
   *_ref.PboResp_ = false;
}

ErrorCode::ErrorCode(ErrorCodeValue _val) :
   enValue_(_val), PboResp_(new bool(true))
{
}

ErrorCode::~ErrorCode()
{
   if (*PboResp_)
      cerr << "Destruction of untested error code: value "
           << enValue_ << endl;

   delete PboResp_;
}

ErrorCode& ErrorCode::operator = (const ErrorCode& _ref)
{
   if (*PboResp_)
      cerr << "Untested error code (value " << enValue_
           << ") erased by new value " << _ref.enValue_ << endl;

   enValue_ = _ref.enValue_;
   *PboResp_ = *_ref.PboResp_;
   *_ref.PboResp_ = false;
  
   return *this;
}

bool ErrorCode::operator != (const ErrorCode& _ref) const
{
   *PboResp_ = false;
   *_ref.PboResp_ = false;

   return (enValue_ != _ref.enValue_);
}