Path: utzoo!utgpu!jarvis.csri.toronto.edu!rutgers!uwvax!tank!eecae!shadooby!sharkey!mcf!mibte!gamma!thumper!ulysses!andante!alice!shopiro
From: shopiro@alice.UUCP (Jonathan Shopiro)
Newsgroups: comp.lang.c++
Subject: Re: Any interest in making C++ a real superset of ANSI C?
Summary: class and struct are identical except for publicity
Message-ID: <9408@alice.UUCP>
Date: 30 May 89 02:40:23 GMT
References: <26575@watmath.waterloo.edu> <10213@claris.com>
Organization: AT&T Bell Laboratories, Murray Hill NJ
Lines: 27

In article <10213@claris.com>, kevin@claris.com (Kevin Watts) writes:
> Walter Bright's suggestion (struct as in C, class as in C++) seems like a
> reasonable compromise.  It brings up a question: is there any penalty for
> using class where struct would do?

In C++, class and struct are identical, except that base classes and
members of structs are public by default, and base classes and members
of classes are private by default.  In both cases the default can be
overridden with the ``public'' and ``private'' (and ``protected'' for
members) keywords.  These choices have no runtime performance
consequences whatsoever.

In my opinion, this distinction between class and struct is easy to
understand and use.  I think the kinds of changes that have been
suggested might make it easier to port code from C to C++, but they
would make C++ itself harder to understand and use.

Note: in the latest version of C++, a warning is generated if the base
class of a class is private by default.  Use the ``private'' keyword
explicitly and the warning goes away.



-- 
		Jonathan Shopiro
		AT&T Bell Laboratories, Warren, NJ  07060-0908
		research!shopiro   (201) 580-4229