Article View: comp.bugs.4bsd
Article #544Re: C preprocessor question
From: pedz
Date: Wed, 04 Feb 1987 17:11
Date: Wed, 04 Feb 1987 17:11
19 lines
1351 bytes
1351 bytes
In article <55@umich.UUCP> jtr485@umich.UUCP (Johnathan Tainter) writes:
>The #if is not going to evaluate the expression (((0) << 8) | (0))
>The #if takes an expression defined (recursively) by:
>an <expression> is
> 1) an integer string
> or 2) (<expression> | <expression>)
> or 3) (<expression> & <expression>)
>and nothing else.
This may be how it works but is not how it is defined. The value
after the #if is suppose to be a constant expression. Constant
expressions include almost all of the operators including << and
?:. I refer you to K&R section 15 page 211. Notice that it is
suppose to include sizeof which cpp can not cope with either. i.e.
cpp is -----.
--
Perry Smith
pedz@bobkat
{ti-csl,infotel}!pollux!bobkat!pedz
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Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Path: arc1-ca.pugleaf.net!utzoo!watmath!clyde!rutgers!seismo!ut-sally!ut-ngp!infotel!pollux!bobkat!pedz From: pedz@bobkat.UUCP Newsgroups: comp.bugs.4bsd Subject: Re: C preprocessor question Message-ID: <539@bobkat.UUCP> Date: Wed, 4-Feb-87 12:11:50 EST Article-I.D.: bobkat.539 Posted: Wed Feb 4 12:11:50 1987 Date-Received: Sat, 7-Feb-87 11:44:24 EST References: <818@wjvax.wjvax.UUCP> <55@umich.UUCP> Reply-To: pedz@bobkat.UUCP (Pedz Thing) Organization: Digital Lynx, Inc; Dallas, TX Lines: 19 Keywords: preprocessor, UNIX, BSD