Path: utzoo!attcan!uunet!kddlab!titcca!sragwa!wsgw!socslgw!diamond
From: diamond@csl.sony.JUNET (Norman Diamond)
Newsgroups: comp.lang.c++
Subject: Re: Is this a compiler bug ?
Summary: No, it's your bug
Keywords: G++
Message-ID: <10022@diamond.csl.sony.JUNET>
Date: 27 Jan 89 06:02:59 GMT
References: <435@tnosoes.UUCP>
Organization: Sony Computer Science Laboratory Inc., Tokyo, Japan
Lines: 21

In article <435@tnosoes.UUCP>, tom@tnosoes.UUCP (Tom Vijlbrief) writes:
> When compiling a file of the OOPS package, G++ (1.32) produced an
> errormessage for the following function:
>         ((Date)*this).printOn(strm);    // Error !

When you cast the result of *this, it is like assigning the
result of *this to a temporary variable of type Date.  When
you give a command to a temporary variable and then have no
further use for that variable, you don't accomplish much.

>         ((Date *)this)->printOn(strm);  // No Error !

Aha.  When you have sort of a temporary variable of type
(Date *), it still points to your own instance.  You then
command your own instance to do something, and you get
what you want.
-- 
Norman Diamond, Sony Computer Science Lab (diamond%csl.sony.jp@relay.cs.net)
  The above opinions are my own.   |  Why are programmers criticized for
  If they're also your opinions,   |  re-inventing the wheel, when car
  you're infringing my copyright.  |  manufacturers are praised for it?