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From: guy%gorodish@Sun.COM (Guy Harris)
Newsgroups: news.software.b
Subject: Re: News for Xenix on PC AT ?
Message-ID: <17896@sun.uucp>
Date: Sun, 3-May-87 13:53:16 EDT
Article-I.D.: sun.17896
Posted: Sun May  3 13:53:16 1987
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> Pardon me???!  (void *) is a GENERIC pointer, is it not?

If a pointer of type "void *" is a generic C pointer, it is also a
square circle, a method for trisecting an angle with compass and
straightedge, and an expansion of "pi" to the last decimal place.
None of the objects described exist.

A pointer of type "void *" is just a pointer that can receive the
properly-coerced value of any pointer; said coercion must be
reversable.  From the October 1, 1986 ANSI C draft:

	3.2.2.3 Pointers

	   A pointer to "void" may be converted to a pointer to an
	object of any type.  A pointer to an object of any type may
	be convetrted to a pointer to "void" and back again; the
	result shall compare equal to the original pointer.

> It should, in theory, be a type pun in all situations

I can't quite parse this.  A type pun is an action, not an object, so
a pointer of type "void *" cannot be a type pun.

> (if casting the result of a rational malloc() (defined as returning
> (void *)) changes the representation of the pointer returned, we've got
> trouble, no?).

No.  Why should it cause any trouble?

> If you have an X3J11 compiler, let me know;

The person in question referred, in passing, to "void *" in such a
way that I inferred that the context of the discussion was of X3J11
compilers.