### 4.16 `iswalnum`, `iswalnum_l`—alphanumeric wide character test ¶

Synopsis

    #include <wctype.h>
    int iswalnum(wint_t c);

    #include <wctype.h>
    int iswalnum_l(wint_t c, locale_t locale);

Description
`iswalnum` is a function which classifies wide-character values that are alphanumeric.

`iswalnum_l` is like `iswalnum` but performs the check based on the locale specified by the locale object locale. If locale is LC_GLOBAL_LOCALE or not a valid locale object, the behaviour is undefined.

Returns
`iswalnum`, `iswalnum_l` return non-zero if c is a alphanumeric wide character.

Portability
`iswalnum` is C99. `iswalnum_l` is POSIX-1.2008.

No supporting OS subroutines are required.