CStdString - This is a string class derived from the Standard C++ Library basic_string<TCHAR>. To this it adds the entire CString set of functions (with three exceptions). It is as close to being a drop-in replacement for CString as you are likely to find. You can use it along with MFC, ATL, or neither.-CStdString- This is a string class derived from the Standard C++ Library basic_string<TCHAR>. To this it adds the entire CString set of functions (with three exceptions). It is as close to being a drop-in replacement for CString as you are likely to find. You can use it along with MFC, ATL, or neither.