- Push one byte back onto the input queue. This will be the
- next byte read from the stream. Any number of bytes can be
- pushed back and will be read in the reverse order they were
- pushed back -- most recent first. (This is necessary for
- consistency -- if there are a number of bytes that have been
- unread and I read and unread a byte, it needs to be the first
- to be read again.) This is a macro and so it is very
- efficient. The C argument is only evaluated once but the
- STREAM argument is evaluated more than once.
+ Push one byte back onto the input queue, cast to unsigned char.
+ This will be the next byte read from the stream. Any number
+ of bytes can be pushed back and will be read in the reverse
+ order they were pushed back -- most recent first. (This is
+ necessary for consistency -- if there are a number of bytes
+ that have been unread and I read and unread a byte, it needs
+ to be the first to be read again.) This is a macro and so it
+ is very efficient. The C argument is only evaluated once but
+ the STREAM argument is evaluated more than once.