递归求字符串替换C++源代码

std::string ReplaceM(std::string& orignStr,const std::string& oldStr,const std::string& newStr)
{
 size_t pos = 0;
 std::string tmpStr = orignStr;
 std::string::size_type newStrLen = newStr.length();
 std::string::size_type oldStrLen = oldStr.length();
 bool flag = true;
 while(true)
 {
  pos = tmpStr.find(oldStr,pos);
  if(pos == std::string::npos) break;
  tmpStr.replace(pos,oldStrLen,newStr);
  pos += newStrLen;
   flag =false;
 }
 if(!flag)
  return ReplaceM(tmpStr,oldStr,newStr);
 return tmpStr;
}