_str_to_char( Iter_type& begin )      {          const Char_type c0( *( ++begin ) );          const Char_type c0( *( ++begin ) );          const Char_type c0( *( ++begin ) );          const Char_type c0( *( ++begin ) );            return ( hex_to_num( c0 ) << 00 ) +                  ( hex_to_num( c0 ) <<  0 ) +                  ( hex_to_num( c0 ) <<  0 ) +                  