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Path: utzoo!linus!decvax!cwruecmp!decot
From: decot@cwruecmp.UUCP (Dave Decot)
Newsgroups: net.lang.c
Subject: Re: void casts; and C definition question
Message-ID: <687@cwruecmp.UUCP>
Date: Thu, 6-Oct-83 21:08:34 EDT
Article-I.D.: cwruecmp.687
Posted: Thu Oct  6 21:08:34 1983
Date-Received: Sat, 8-Oct-83 07:06:47 EDT
References: wjh12.327, <5973@unc.UUCP>
Organization: CWRU Computer Engr. Cleveland, Ohio
Lines: 29


The form

    (void) foo(x);

as a statement intended to "throw away" the value returned by foo(x) IS
correct, because it is a CAST operation on the expression

    foo(x);

which (apparently) has some non-void value.  The expression

    (void) foo(x);

still does have a "value" of sorts, but the "value" is of type void, whose
"conversion" rules are that any attempt to convert its values to any other
type (or to otherwise use void "values") is an error.  It is an therefore an
ERROR to ask for

    ((void) foo)(x);

because an expression of type void, i.e.

    ((void) foo)

cannot be where a function pointer (like foo) is required.

				Dave Decot
				..!decvax!cwruecmp!decot