Otherwise, if this is a variable value, the function returns 0.
Alternatively, if the encoding of an external sequence is state-dependent, the function returns -1.
During its operation, this function simply calls the virtual protected member codecvt::do_encoding, which is the member function in charge of performing the actions described above.
Return valueOne of the following, describing how external characters are encoded:
|-1||Encoding is state-dependent|
|0||Characters have a variable width|
|other values||Fixed amount of external characters equivalent to one internal character|
Characteristics of codecvt<wchar_t,char,mbstate_t>: Encoding: 1 Always noconv: 0 Max length: 5
|codecvt::length||Return length of translated sequence (public member function)|
|codecvt::max_length||Return max length of one character (public member function)|
|codecvt::do_encoding||Return encoding width [virtual] (virtual protected member function)|