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From: bill@robots.oxford.ac.uk (Bill Triggs)
Newsgroups: comp.lang.c++
Subject: 'soft' or calculated class members
Message-ID: <1875@culhua.prg.ox.ac.uk>
Date: 14 Jun 91 19:50:49 GMT
Sender: news@prg.ox.ac.uk
Lines: 32

I have recently been pushing the suggestion that 'soft' or
calculated class members would be easy to implement in C++,
and would be a useful extension of the language.

The basic idea is that while it is good OOP style to 'wrap'
class member access with method calls (for reasons given
below), the resulting code is made difficult to understand
by the resulting brackets, and the valuable conceptual
difference between "little operations which just access
state" and "big operations which actually do something" is
blurred when everything is done with an explicit function
call.

Soft members are class *methods* which can be invoked by a
syntax identical to ordinary *member* accesses (ie,
'foo.bar' not 'foo.bar()'). They can be used to simulate
non-existent 'notional' class members, for various extremely
useful housekeeping tasks, and for easier maintenance of
backward compatibility.

I would like to get the ANSI C++ committee to at least
consider the introduction of soft members into C++, as I
think they would be a great benefit to the language. I
posted a detailed proposal on the net a few weeks ago and
the response was favourable, so I have now posted some
patches which implement soft-members for g++ - look in the
gnu.g++.help newsgroup if you want more details...
-- 
Bill Triggs
Oxford University Computing Laboratory
11 Keble Rd
Oxford OX1 3QD