From: utzoo!decvax!decwrl!sun!megatest!p500vax:pat
Newsgroups: net.unix-wizards
Title: Multiple statements in C macros
Article-I.D.: p500vax.163
Posted: Mon Jan  3 21:14:15 1983
Received: Tue Jan  4 06:18:10 1983


Some time ago mail appeared on the net discussing how best to include
multiple statements in macro definitions.  

Both
#define	M	{ a; b; }
and
#define	M	a; b;

fail in the case of
    if( boolean )
	    M;
	else
	    N;

resulting in an "else without if" syntax error ( or worse ).

An answer lies with that most obscure of C features, the comma operator, 
viz.
#define	M	( a, b )


The advisability of such a practice is debatable.