Re: [boost] Re: is_base_and_derived question

From: David Abrahams (dave_at_[hidden])
Date: 2003-01-30 10:19:53

Gennaro Prota <gennaro_prota_at_[hidden]> writes:

> Actually the reason for my question is a little strange :-) I hope to
> explain it in understandable English: Andrej said
>
>     "void is hardly a supertype of everything"
>
>
> Rewording it, it is: "void is not a supertype of everything".
>
> This immediately made me think to why he didn't say: "not a supertype
> of anything". In other words I wondered: "is he implying that void is
> not a supertype of everything but *is* a supertype of something"? What
> it this "something"? :-) That's an example of my odd mental
> contortions.

Peter D. has effectively argued in the past that void *is* a supertype
of everything (well, every object type, as opposed e.g. to
function/function pointer types).  Given the foregoing discussion
about squares and rectangles it may be the *only* supertype that we
can detect with certainty.

-- 
                       David Abrahams
   dave_at_[hidden] * http://www.boost-consulting.com
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