iswupper - test for uppercase wide character

       For an explanation of the terms used in this section, see attributes(7).
       ┌──────────────────────────────────────────────────────────────────────┬───────────────┬────────────────┐
       │ Interface                                                            │ Attribute     │ Value          │
       ├──────────────────────────────────────────────────────────────────────┼───────────────┼────────────────┤
       │ iswupper()                                                           │ Thread safety │ MT-Safe locale │
       └──────────────────────────────────────────────────────────────────────┴───────────────┴────────────────┘

       The iswupper() function is the wide-character equivalent of the isupper(3) function.  It tests whether wc
       is a wide character belonging to the wide-character class "upper".

       The  wide-character class "upper" is a subclass of the wide-character class "alpha", and therefore also a
       subclass of the wide-character class "alnum", of the  wide-character  class  "graph"  and  of  the  wide-
       character class "print".

       Being  a  subclass of the wide-character class "print", the wide-character class "upper" is disjoint from
       the wide-character class "cntrl".

       Being a subclass of the wide-character class "graph", the wide-character class "upper" is  disjoint  from
       the wide-character class "space" and its subclass "blank".

       Being  a  subclass of the wide-character class "alnum", the wide-character class "upper" is disjoint from
       the wide-character class "punct".

       Being a subclass of the wide-character class "alpha", the wide-character class "upper" is  disjoint  from
       the wide-character class "digit".

       The  wide-character  class  "upper" contains at least those characters wc which are equal to towupper(wc)
       and different from towlower(wc).

       The wide-character class "upper" always contains at least the letters 'A' to 'Z'.

       POSIX.1-2001, C99.

       Standard C library (libc, -lc)

       iswupper - test for uppercase wide character

       The behavior of iswupper() depends on the LC_CTYPE category of the current locale.

       This  function  is  not very appropriate for dealing with Unicode characters, because Unicode knows about
       three cases: upper, lower, and title case.

       The iswupper() function returns nonzero if wc is a wide character belonging to the  wide-character  class
       "upper".  Otherwise, it returns zero.

isupper(3), iswctype(3), towupper(3)

Linux man-pages 6.9.1                              2024-05-02                                        iswupper(3)

       C11, POSIX.1-2008.

#include<wctype.h>intiswupper(wint_twc);