#   ifdef BOOST_WINDOWS_PATH
      // for BOOST_WINDOWS_PATH, convert alt_separator ('\') to separator
('/')
      bool is_alt_separator = (value == path_alt_separator<path_type>::value);

      if(std::string(std::setlocale(LC_ALL, "")).find(".950")){
          m_path += value;
          if(is_alt_separator){
              std::string::const_iterator it = m_path.end();
              --it; int lsb = *(it);
              --it; int msb = *(it);
              if(!detail::is_big5_char(0xff & msb, 0xff & lsb)){
                 // not a part of the big5 char, patching it.
                 *(--m_path.end()) = slash<path_type>::value;
              }
          }
      } else {
          m_path += ( is_alt_separator ? slash<path_type>::value: value );
      }
#   else
      m_path += value;
      m_path += value;
#   endif
    }



// check two bytes could be a valid big5 char.

      bool is_big5_char(int msb, int lsb){
  		bool ret = false;
  		if(msb >= 0x81 && msb <= 0xfe){
  			if(lsb >= 0x40 && lsb <= 0x7e){
  				ret = true;
  			}
  			if(lsb >= 0xa1 && lsb <= 0xfe){
  				ret = true;
  			}
  		}
  		return ret;
      }