Originální popis anglicky:
iswupper - test for uppercase wide character
Návod, kniha: Linux Programmer's Manual
#include <wctype.h>
int iswupper(wint_t wc);
The
iswupper function is the wide-character equivalent of the
isupper 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'.
The
iswupper function returns non-zero if
wc is a wide character
belonging to the wide character class "upper". Otherwise it returns
zero.
ISO/ANSI C, UNIX98
isupper(3),
iswctype(3),
towupper(3)
The behaviour 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.
