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From: steve@taumet.com (Stephen Clamage)
Newsgroups: comp.lang.c++
Subject: Re: Public vs Private header files in C++
Message-ID: <757@taumet.com>
Date: 4 Jun 91 15:39:22 GMT
Article-I.D.: taumet.757
References: <5243@servax0.essex.ac.uk> <1991Jun3.182909.21539@agate.berkeley.edu> <5tdHm72m@cs.psu.edu> <53598@apple.Apple.COM>
Organization: Taumetric Corporation, San Diego
Lines: 18

cep@Apple.COM (Christopher Pettus) writes:

>The _real_ reason is, of course, the same: without full compiler access
>to the class definition, it's size could not be determined, which
>violates the classes-as-primitive-types goal of C++ (which is a worthy
>one).

The compiler needs to know more than the class size.  The offset of a
public data member depends on all previous data members, and the index
of a public virtual function depends on all previous virtual functions.
So code which references only public members of a class in general still
needs to include a complete class declaration.

One can argue about the merits of this feature of C++ language design,
but partial class definitions are nevertheless not allowed.
-- 

Steve Clamage, TauMetric Corp, steve@taumet.com