Re: [patch 2.6.13-rc3] i386: clean up user_mode macros

From: Miles Bader
Date: Mon Jul 25 2005 - 20:30:50 EST

Linus Torvalds <torvalds@xxxxxxxx> writes:
> Ask a hundred random C programmers what "!!x" means, versus what "x != 0"
> means, and time their replies.

I've always thought of "!!" as the "canonicalize boolean" operator...

Vaguely ugly, but I think it's actually _more clear_ than != 0 in
contexts where the value is already "boolean" in the C zero or not-zero
sense, but you want a "proper" boolean (0 or 1) for some reason.

Somebody has to do something, and it's just incredibly pathetic that it
has to be us. -- Jerry Garcia
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