The wctob() function shall determine whether c corresponds to a
member of the extended character set whose character representation is a
single byte when in the initial shift state.
The behavior of this function shall be affected by the LC_CTYPE category
of the current locale.
The wctob() function shall return EOF if c does not correspond to
a character with length one in the initial shift state. Otherwise, it shall
return the single-byte representation of that character as an unsigned
char converted to int.
Portions of this text are reprinted and reproduced in electronic form from IEEE
Std 1003.1, 2003 Edition, Standard for Information Technology -- Portable
Operating System Interface (POSIX), The Open Group Base Specifications Issue
6, Copyright (C) 2001-2003 by the Institute of Electrical and Electronics
Engineers, Inc and The Open Group. In the event of any discrepancy between
this version and the original IEEE and The Open Group Standard, the original
IEEE and The Open Group Standard is the referee document. The original
Standard can be obtained online at http://www.opengroup.org/unix/online.html