IsWCType
int IsWCType(wint_t wc, wctype_t charClass);
virtual int IsWCType(wint_t wc, wctype_t charClass);
virtual int IsWCType(wint_t wc, wctype_t charClass) = 0;
return fCtypeData.IsWCType(wc, charClass);
return backend->IsWCType(wc, charClass);
return backend->IsWCType(wc, charClass);