Path: utzoo!mnetor!uunet!husc6!think!bloom-beacon!tut.cis.ohio-state.edu!im4u!ut-sally!utah-cs!utah-gr!uplherc!sp7040!obie!wes
From: wes@obie.UUCP (Barnacle Wes)
Newsgroups: comp.lang.c
Subject: Re: == vs =
Message-ID: <130@obie.UUCP>
Date: 8 Apr 88 16:26:55 GMT
References: <11216@brl-adm.ARPA> <2111@chinet.UUCP> <4403@garfield.UUCP> <226@hotlr.ATT>
Organization: the Well of Souls
Lines: 22
Summary: = is sometimes valid in if ()

In article <226@hotlr.ATT>, dkc@hotlr.ATT (Dave Cornutt) writes:
> [...]                               D is another matter; catching the
> accidental misapplication of "=" in "if" statements would be worth it.

The one thing that everyone seems to have forgotten in this discussion
is that `=' is NOT always invalid in and if clause:

volatile short *statreg = (short *) 0x00FFC000L;
...
    short status;
    ...
    if (status = *statreg) {
	do something with status;
    }

Code like this would (perhaps) be used for polling hardware status
registers.  Remember, C is supposed to be a general-purpose language!
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