c ++使用方法const的遗留代码,仍然需要创建采用const方法成员的函数

Question

我有遗留的c ++代码是const方法:

Id LegacyCode::GetIdByName(const char* sName,
                          const char* pName) const
{

  long lID;
  char szProcessName[MAXPATH];
  for (int iP = 0;
       iP < iNum;
       iP++) {

      if (strnicmp(sName, "Test.exe", MAX_LENGTH) == 0)
      {       
          if (strnicmp(szProcessName, pName, MAX_LENGTH) == 0)
          {
              // If the proces name was found, return its ID.

                return (lID);
          }
      }
      else if (strnicmp(sName, "Test2.exe", MAX_LENGTH) == 0)
      {       
          if (strnicmp(szProcessName, pName, MAX_LENGTH) == 0)
          {
              // If the proces name was found, return its ID.

                return (lID);
          }
      }
      else
      {

        if (strnicmp(sName, szProcessName, MAX_LENGTH) == 0)
         return (lID);
      }
  }

  return (0);
}

我喜欢用更好的代码替换它,使用辅助函数

Id LegacyCode::GetIdByName(const char* sName,
                          const char* pName) const
{

  long lID;
  char szProcessName[MAXPATH];
  for (int iP = 0;
       iP < iNum;
       iP++) {

      if (isProcessName(sName,pName,szProcessName))
      {          
                return (lID);

      }
      else
      {

        if (strnicmp(sName, szProcessName, MAX_LENGTH) == 0)
         return (lID);
      }
  }

  return (0);
}


bool LegacyCode::isProcessName(char* _sName,char* _pName,char* _szProcessName)
{
       if (strnicmp(_sName, "Test.exe", MAX_LENGTH) == 0)
      {       
          if (strnicmp(_szProcessName, pName, MAX_LENGTH) == 0)
          {
              // If the proces name was found, return its ID.

                return (lID);
          }
      }
      else if (strnicmp(sName, "Test2.exe", MAX_LENGTH) == 0)
      {       
          if (strnicmp(_szProcessName, pName, MAX_LENGTH) == 0)
          {
              // If the proces name was found, return its ID.

                return (lID);
          }
      }
      return false;
}

但不幸的是我得到const错误:

error C2662: 'LegacyCode::isProcessName' : cannot convert 'this' pointer from 'const LegacyCode' to 'LegacyCode &'

是否有任何方法可以克服这个问题,而不增加功能膜的可变性？

Answer 1

使LegacyCode::isProcessNameconst:

bool LegacyCode::isProcessName(char* _sName,char* _pName,char* _szProcessName) const;