RE: macro conflict

From: Camiel Vanderhoeven (camiel_toronto@hotmail.com)
Date: Thu Aug 23 2001 - 20:42:52 EST


A small detail; you min(x,y) fails if x and y are pointers.

Example: min(char * a, char * b) would evaluate to
char * __x = (a), __y = (b); etc...

Here __x is a pointer and __y is a char. A better solution (at least the
one that has my vote so far) would besomething like this:

typeof(x) __x=(x); typeof(y) __y=(y); (__x < __y) ? __x : __y

Camiel.

> Without digging through the archives to see if this has already
> been suggested (if so, I apologize), why can't the following be done:
>
> min(x,y) = ({typeof((x)) __x=(x), __y=(y); (__x < __y) ? __x : __y})
>
> That gets you the correct "evaluate the args once" semantics and gives
> you control over typing (the comparison is done in the type of the
> first argument) and we don't have to change a zillion drivers.
>
> (typeof() is a gcc extension.)
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