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From: David R Tribble <dtribble@technologist.com>
Subject: Re: Is this well-formed?
Date: 1999/04/27
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David R Tribble <dtribble@technologist.com> wrote
>>> Gee, wouldn't it be nice if C++ had a 'null' keyword?

Christopher Eltschka wrote:
>...
> However, it doesn't really need a keyword, the following
> should work on a conforming compiler:
>...
> 
>  class null
>  {
>  public:
>    template<class T> operator T*() { return 0; }
>    static null get() { return null(); }
>  private:
>    null();
>    null(null const&);
>  };
>  
>  #define null (null::get())

Nice little addition, that rvalue thing.

I know there's no chance of getting this widely accepted in any
"standard" sense, but wouldn't this be fairly easy to add to g++?
This would help establish "existing practice" for the next
go-around on std C++.

I saw somewhere that one version of the compiler used '__NULL__'
as a real built-in null constant (which the header files
conveniently #defined NULL to be).

I must also re-iterate my opinion on adding 'null' to C++, that
this should not in any way replace the use of 0, at least for
several years.  Eventually, if enough people haved switched
from 0 to 'null', we can argue about getting rid of "0 as null";
but this won't happen for a while yet, if ever.

-- David R. Tribble, dtribble@technologist.com --


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