Path: utzoo!utgpu!attcan!uunet!seismo!sundc!pitstop!sun!amdcad!ames!nrl-cmf!cmcl2!phri!marob!daveh
From: daveh@marob.MASA.COM (Dave Hammond)
Newsgroups: comp.lang.c
Subject: Re: Calling multiple functions in a macro.
Message-ID: <354@marob.MASA.COM>
Date: 2 Nov 88 17:16:42 GMT
References: <353@marob.MASA.COM> <7462@ihlpl.ATT.COM>
Reply-To: daveh@marob.masa.com (Dave Hammond)
Organization: ESCC  New York City
Lines: 18

In article <7462@ihlpl.ATT.COM> knudsen@ihlpl.ATT.COM (Knudsen) writes:
>In article <353@marob.MASA.COM>, daveh@marob.MASA.COM (Dave Hammond) writes:
>> #define FOO()	do { foo1(); foo2(); foo3() foo4(); } while(0)
>Why use the do and while?  C has blocks, you can say just plain
>	{foo1(); ... foo4();}
>Of course all you're really doing is supplying the braces so the
>macro can be used "without braces" in the source.
>I dimly recall defining macros wrapped in {}; they worked fine.

Except that invoking FOO(); (note the semicolon) introduces a null
statement which could easily throw off the flow (or fail to compile)
if used within a conditional expression.  You would have to to invoke
FOO() without a terminating semicolon which, to me, is unnatural.

Dave Hammond
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