Path: utzoo!attcan!uunet!lll-winken!lll-lcc!ames!husc6!rutgers!att!ihlpb!nevin1
From: nevin1@ihlpb.ATT.COM (Liber)
Newsgroups: comp.lang.c
Subject: Re: hardcoded constants
Message-ID: <9244@ihlpb.ATT.COM>
Date: 22 Dec 88 00:38:10 GMT
References: <2636@m2-net.UUCP> <1104@goofy.megatest.UUCP>
Reply-To: nevin1@ihlpb.UUCP (55528-Liber,N.J.)
Organization: AT&T Bell Laboratories - Naperville, Illinois
Lines: 24

In article <1104@goofy.megatest.UUCP> djones@megatest.UUCP (Dave Jones) writes:
>From article <2636@m2-net.UUCP>, by remmers@m-net.UUCP (John H. Remmers):
 
>> 	#define  Catspace(s,t)  (strlen(s) + strlen(t) + 1)

>You are a candidate for SLMA (Silly Little Macros Anonymous). [:-)]

>But if you don't like the naked "1", how about this?

>foo =  malloc( strlen(s) + strlen(t) + sizeof('\0'));

>Tells it all.  And keeps the reader on track, not grepping around
>for macros.

It also happens to be WRONG!  (Actually, if you are only using it for
malloc(), it will work; you just end up allocating more space than is
actually needed.)  Quoting from dpANS C 10/88 draft, section 3.1.3.4
(character constants), subsection on semantics (p 30):

	"An integer character constant has type int."

This means, among other things, that sizeof('\0') == sizeof(int), and
not sizeof(char).
-- 
NEVIN ":-)" LIBER  AT&T Bell Laboratories  nevin1@ihlpb.ATT.COM  (312) 979-4751