#include <wctype.h> int iswalnum(wint_t wc);
The wide-character class "alnum" is a subclass of the wide-character class "graph", and therefore also a subclass of the wide-character class "print".
Being a subclass of the wide-character class "print", the wide-character class "alnum" is disjoint from the wide-character class "cntrl".
Being a subclass of the wide-character class "graph", the wide-character class "alnum" is disjoint from the wide-character class "space" and its subclass "blank".
The wide-character class "alnum" is disjoint from the wide-character class "punct".
The wide-character class "alnum" is the union of the wide-character classes "alpha" and "digit". As such, it also contains the wide-character class "xdigit".
The wide-character class "alnum" always contains at least the letters aqAaq to aqZaq, aqaaq to aqzaq and the digits aq0aq to aq9aq.