🚀 go-pugleaf

In article 6o7@fu-berlin.de, axl@zedat.fu-berlin.de (Axel Thimm) writes:

>kanze@gabi-soft.fr (J. Kanze) wrote:

>>You might want to try the function `peek'.  I tend to use this function
>>a lot.  Basically, this forces a look-ahead, which will set the eof if
>>there is nothing more there.

>But I think that you can use this only with text streams, not with
>binary streams (You would not be able to tell a eof-char from an
>ordinary binary char).

No, it must work. EOF is required to have a value different from every
character value. The character-reading functions that can return either
a character or EOF return a type that that can represent the EOF value
as distinct from any character value.

In a traditional implementation, EOF has the int value -1, and characters
have 8-bit values. The peek function returns the character value promoted
to type int without sign extension, as if by the cast sequence
	(int)(unsigned char)the_value
Such a value cannot compare equal to the int value -1.

The situation is more complicated for wide characters, but the principle
remains.
---
Steve Clamage, stephen.clamage@eng.sun.com
---
[ To submit articles: try just posting with your news-reader.
                      If that fails, use mailto:std-c++@ncar.ucar.edu
  FAQ:      http://reality.sgi.com/employees/austern_mti/std-c++/faq.html
  Policy:   http://reality.sgi.com/employees/austern_mti/std-c++/policy.html
  Comments? mailto:std-c++-request@ncar.ucar.edu.
]