Path: utzoo!utgpu!water!watmath!clyde!att-cb!att-ih!pacbell!ames!ucsd!sdcsvax!ucsdhub!hp-sdd!hplabs!sdcrdcf!markb
From: markb@sdcrdcf.UUCP (Mark Biggar)
Newsgroups: comp.lang.c
Subject: Re: Machine specific predefined names
Message-ID: <5202@sdcrdcf.UUCP>
Date: 1 Apr 88 18:40:21 GMT
References: <1988Feb17.115402.12739@light.uucp> <17033@watmath.waterloo.edu> <242@sdrc.UUCP> <378@wsccs.UUCP> <3225@haddock.ISC.COM> <598@tuvie> <3264@haddock.ISC.COM>
Reply-To: markb@sdcrdcf.UUCP (Mark Biggar)
Organization: Unisys - System Development Group, Santa Monica
Lines: 21

In article <3264@haddock.ISC.COM> karl@haddock.ima.isc.com (Karl Heuer) writes:
|In article <598@tuvie> rcvie@tuvie.UUCP (Alcatel-ELIN Forsch.z.) writes:
||In article <3225@haddock.ISC.COM> karl@haddock.ima.isc.com (Karl Heuer) writes:
||>If you try to redefine *any* standard routine -- whether macro or function
||>-- the result should be, and is, undefined.  Why should the user be forced
||>to learn the implementation details?
||Just try the portable way and noone has to learn anything but that there
||*are* some routines implemented as functions and some as macros:
||  #undef putchar
||  <your putchar-macro/function>
|That isn't portable.  After you've redefined something, you have no way of
|knowing whether other library routines (e.g. puts) will be using your putchar
|or the standard one.
I thought the standard included a guarantee that if you did the above that
the libraries would still continue to use the original definition.
In fact the whole reason for the necessity of using the #undef etc. was to
allow for that guarantee.

Mark Biggar
{allegra,burdvax,cbosgd,hplabs,ihnp4,akgua,sdcsvax}!sdcrdcf!markb
markb@rdcf.sm.unisys.com