Indirect comma assigned from side effects

[Tomas Rokicki]

In article <3047 at umcp-cs.UUCP>, chris at umcp-cs.UUCP (Chris Torek) writes:
> In article <792 at navajo.STANFORD.EDU> I write:
> >
> >	int lhs, rhs, index; int *pointers[9];
> >	foo() { *( index=lhs, pointers[index] ) = sideeffects(); }
> >
> >The question is, does C allow for the possibility that the order
> >of evaluation might be "index=lhs" then "sideeffects()" then
> >"*pointers[index]=<result>"?
>
> No.  The compiler can, however, effectively generate either of the
> following:
> 

Can someone second this, or show me the appropriate reference?
It's Microsoft 4.0 that's putting the sideeffects() call between
the two parts of the comma expression, and sideeffects() modifies
index . . . you get the idea.  I could find nothing in K&R, but
I'm only been hacking C for a year or so.

I just tested under 4.3bsd; cc also puts the sideeffects() in the
middle.  Comments, anyone?

Thanks!   -tom