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From: NET-RELAY.ARPA>@brl-smoke.ARPA
Newsgroups: net.lang.c
Subject: Must casting destroy lvalueness?
Message-ID: <4617@brl-smoke.ARPA>
Date: Wed, 15-Oct-86 06:35:01 EDT
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Posted: Wed Oct 15 06:35:01 1986
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I'm relatively new to info-c and don't know if you've had this debate
so just banish me to the archive if you have.

C pedants claim that casting destroys lvalueness.  Their argument is
essentially that they can imagine a machine on which casting forces
the use of a temp so lvalueness is gone.

C users, on the other hand, find they have to program real machines not
hypothetical ones and that almost all of these real machines don't use a 
temp when casting.  For example, a useful and readable way to move a pointer 
through a buffer containing a mixture of objects of different sizes is 

                       ((OBJECT)pointer)++

This construct is disallowed by Harbison's compiler. 

I fear that the C standards committee is going to take away such practical 
constructs and turn production quality C compilers into academic quality 
ones.  Who knows, there may develop a brisk business in C compilers that 
promise NOT to be standard conforming.

How sayeth the C standard committee?  How sayeth the users?

                                                        Regards, Scott

"You can hack any formalism so why not have useful formalisms?"