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From: twagner@baobab.berkeley.edu (Tim Wagner)
Newsgroups: comp.lang.c++
Subject: Re: const
Message-ID: <27503@pasteur.Berkeley.EDU>
Date: 5 Sep 90 21:59:30 GMT
References: <10863@cadillac.CAD.MCC.COM>
Sender: news@pasteur.Berkeley.EDU
Reply-To: twagner@baobab.berkeley.edu (Tim Wagner)
Lines: 26


In article <10863@cadillac.CAD.MCC.COM>, vaughan@puma.cad.mcc.com (Paul
Vaughan) writes:
|> 
|> Awhile back I posted a message asking if const was really worth the
|> trouble.  Everyone who replied either on the net or privately thought
|> that making a program const correct was indeed worth the effort.
|> These were all pretty subjective opinions--it's kind of hard to
|> measure how much difference it makes.
|> 
|> So, here's a const question.
|> [deleted]

This points out once again the problems inherent in C's (and therefore C++'s)
use of 'const'.  The return type of the function is not a good mechanism
in this case: obviously, one cannot really alter the returned value anyhow,
so calling it 'const' is redundant.  However, the context in which that
returned value is used should be controlled; that is, an lvalue getting
such a returned object should be const itself.  That brings us to the
problem of "really constant" versus "sometimes contstant" which has already
been beaten to death (by me and others--see back issues for more).

In other words, you're right; it's ugly and broken.

Tim Wagner
twagner@sequoia.Berkeley.EDU