The __ctype_b_loc
function shall return a pointer into an array of
characters in the current locale that contains characteristics for each
character in the current character set. The array shall contain a total of
384
characters, and can be indexed with any signed or unsigned char (i.e. with an
index value between -128
and
255
). If the application is multithreaded, the
array shall be local to the current thread.
This interface is not in the source standard; it is only in the binary standard.