template<typename_CharT>
struct __gnu_cxx::_Char_types< _CharT >"Mapping from character type to associated types.
Note
This is an implementation class for the generic version of char_traits. It defines int_type,
off_type, pos_type, and state_type. By default these are unsigned long, streamoff, streampos, and
mbstate_t. Users who need a different set of types, but who don't need to change the definitions of
any function defined in char_traits, can specialize __gnu_cxx::_Char_types while leaving
__gnu_cxx::char_traits alone.