Re: [IDEA+RFC] Possible solution for min()/max() war

Rick Hohensee (humbubba@smarty.smart.net)
Wed, 5 Sep 2001 21:51:58 -0400 (EDT)


>VDA
>#define min2(a,b) ({ \
> typeof(a) __a = (a); \
> typeof(b) __b = (b); \
> if( sizeof(a) != sizeof(b) ) BUG(); \
> if( ~(typeof(a))0 > 0 && ~(typeof(b))0 < 0) BUG(); \
> if( ~(typeof(a))0 < 0 && ~(typeof(b))0 > 0) BUG(); \
> (__a < __b) ? __a : __b; \
> })
>
>#define min3(type,a,b) ({ \
> type __a = (a); \
> type __b = (b); \
> if( sizeof(a) > sizeof(type) ) BUG(); \
> if( sizeof(b) > sizeof(type) ) BUG(); \
> (__a < __b) ? __a : __b; \
> })
>

DesJardin's argument is finely crafted, but does this support it? Is min3
intended to be what Linus was talking about? I usually use m4 when I need
conditionals in macros, and I don't use C conditional statements much, but
isn't what Linus was saying simply something like...

#define min(type,a,b) (type) a < (type) b ? (type) a : (type) b ;

Looking at the trade-offs should account for the simplicity. Even if my
code is wrong, it's about reflective of the required complexity, y/n?
The simple form doesn't catch things. That's OK for a default. Maybe
that's what you want. If it's simple you know what you have, regardless.
"programmer error" is frequently a sign of compiler mis-design.

One reason I'm speaking in support of Linus on this one is that there's
something oddly Forth-like to a simple min(type,a,b). No coder nowhere
knows simplicity like Chuck Moore. Linux is ripe for a bit of that. The
other thing about the 3-arg min thing is that it's rather original, and it
amuses me to see Linus get disrespected for a quantum of real creativity
in his own forum. Linux is also ripe for a bit of free thinking. What's
open source for if all it helps is closed minds?

Rick Hohensee
www.
cLIeNUX
.com
humbubba@smart.net
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