From: Lars Magne Ingebrigtsen <larsi@gnus.org>
To: Stefan Monnier <monnier@iro.umontreal.ca>
Cc: Reuben Thomas <rrt@sc3d.org>, 9222@debbugs.gnu.org
Subject: bug#9222: 23.3.50; "void" is not "typeless" (but thanks for the koan!)
Date: Sun, 11 Sep 2011 05:30:24 +0200 [thread overview]
Message-ID: <m3sjo3ycvj.fsf@stories.gnus.org> (raw)
In-Reply-To: <jwvvcszsr81.fsf-monnier+emacs@gnu.org> (Stefan Monnier's message of "Sat, 10 Sep 2011 23:25:10 -0400")
Stefan Monnier <monnier@iro.umontreal.ca> writes:
> PS: Of course, in C the "void" type is more like the "unit" type than
> like the empty type, i.e. a type with a single value which hence doesn't
> carry any information. E.g. a function that returns a type void can
> return, tho its return value carries no information ("it returns
> nothing") whereas a function that returns the empty type is a function
> that will never return (since there is no value in the empty type, the
> function can never return a value of the right type).
I was thinking more of functions that take void* as a parameter. What's
usually expressed by that is "here's some memory that we're not actually
telling you what the type of is explicitly", so it's (sort of) a pointer
to something typeless. It's not a pointer to something of an empty
type. :-)
So calling "void" a "typeless type" makes some sense. At least to me --
in a C context.
--
(domestic pets only, the antidote for overdose, milk.)
bloggy blog http://lars.ingebrigtsen.no/
next prev parent reply other threads:[~2011-09-11 3:30 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-08-02 13:12 bug#9222: 23.3.50; "void" is not "typeless" (but thanks for the koan!) Reuben Thomas
2011-09-11 1:59 ` Lars Magne Ingebrigtsen
2011-09-11 3:25 ` Stefan Monnier
2011-09-11 3:30 ` Lars Magne Ingebrigtsen [this message]
2011-09-11 4:56 ` Stefan Monnier
2011-09-11 8:13 ` Reuben Thomas
2011-09-11 8:45 ` Andreas Schwab
2011-09-11 14:38 ` Drew Adams
2011-09-12 12:39 ` Stefan Monnier
2019-10-14 16:08 ` Stefan Kangas
2019-10-14 19:01 ` Stefan Monnier
2019-10-14 19:38 ` Stefan Kangas
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