From:	Dietmar Kuehl <dietmar DOT kuehl AT claas-solutions DOT de>
Newsgroups:	comp.os.msdos.djgpp
Subject:	Re: covariant return types
Date:	Fri, 13 Aug 1999 15:52:06 GMT
Organization:	Deja.com - Share what you know. Learn what you don't.
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References:	<934394159 DOT 15217 AT www DOT remarq DOT com>
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In article <934394159 DOT 15217 AT www DOT remarq DOT com>,
  Dr Soil <c DOT b DOT s DOT teh AT reading DOT ac DOT uk> wrote:
> class base
> {
>    virtual base *Get();
> }
>
> class der : public base
> {
>    virtual der *Get();
> }

This code does, of course, not compile! But the problem is not that
covariant return types are not implemented but rather that there are
two semicolon missing in this code. I don't know what version of gcc
the current djgpp is based on but gcc support covariant returns since
quite a while (I think covariant returns where in prior to gcc-2.7.2). Thus,
I would expect that it does support this stuff. However, it apparently has
problems in more complex cases:

  class foo { virtual foo* clone(); };
  class bar { virtual bar* clone(); };
  class foobar: virtual foo, virtual bar { foobar* clone(); };

This does not zet work.
--
<mailto:dietmar DOT kuehl AT claas-solutions DOT de>
homepage: <http://www.informatik.uni-konstanz.de/~kuehl>


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