Determines whether a character is an ASCII upper case letter.
Unlike the standard C library isupper() function,
this only recognizes standard ASCII letters and ignores the locale,
returning FALSE for all non-ASCII characters. Also unlike the standard
library function, this takes a char, not an int,
so don't call it on EOF but no need to worry about casting to guchar
before passing a possibly non-ASCII character in.
Determines whether a character is an ASCII upper case letter. Unlike the standard C library isupper() function, this only recognizes standard ASCII letters and ignores the locale, returning FALSE for all non-ASCII characters. Also unlike the standard library function, this takes a char, not an int, so don't call it on EOF but no need to worry about casting to guchar before passing a possibly non-ASCII character in.