Path: utzoo!utgpu!watserv1!watmath!iuvax!mailrus!accuvax.nwu.edu!nucsrl!squires
From: squires@eecs.nwu.edu (Matt Squires)
Newsgroups: comp.lang.c
Subject: Re: ?:
Message-ID: <3950015@eecs.nwu.edu>
Date: 7 Feb 90 22:22:11 GMT
References: <6200014@ux1.cso.uiuc.edu>
Organization: Northwestern U, Evanston IL, USA
Lines: 24

In comp.lang.c, phil@ux1.cso.uiuc.edu writes:

> Do any compilers accept this kind of syntax (which as far as I can tell is
> bogus C since ?: does not yield an lvalue, but is not ambiguous):
> 
>     ( a == b ? x : y ) += z;    /* x and y are lvalues */
> 
> as equivalent to:
> 
>     if ( a == b ) x += z; else y += z;

Sure, GNU's GCC does.  From the GCC info page:

< A conditional expression is a valid lvalue if its type is not void and the
< true and false branches are both valid lvalues.  For example, these two
< expressions are equivalent:
< 
< @example
< (a ? b : c) = 5
< (a ? b = 5 : (c = 5))
< @end example

Matt "Local GNUisance" S.
squires@eecs.nwu.edu