Re: [BUG] Bad #define, nonportable C, missing {}

From: Alexander Viro (viro@math.psu.edu)
Date: Wed Nov 21 2001 - 09:52:22 EST


On 21 Nov 2001, Andreas Schwab wrote:

> Jan Hudec <bulb@ucw.cz> writes:
>
> |> > On Wed, Nov 21, 2001 at 12:40:17PM +0000, vda wrote:
> |> > If you wanna do this type of cleanup, you can take it one step forward;
> |> > remember that the order of evaluation of foo and bar doesn't have to be
> |> > {foo => bar} so it can be {bar => foo} I hope gcc's behaviour doesn't
> |> > change under our feet.
> |> >
> |> > a = foo (i) + bar (j);
> |> >
> |> > .. sprinkle some pointer arithmetic over there for fun ;)
> |>
> |> AFAIK here the order *IS* defined. + operator is evaluated left to right
>
> No. It is undefined which of the operator's arguments is evaluated first,
> unless it is defined otherwise (only for ||, && and comma).

I suspect that real source of problem here is confusion with parsing -
+ operators are _grouped_ left to right. I.e. a+b+c is parsed as (a+b)+c.
Which has nothing to order of evaluation of a, b and c...

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