[boost] Re: boost::any: explicit constructor?

From: Kevlin Henney (kevlin_at_[hidden])
Date: 2004-03-09 06:47:00

In message <uekscadmf.fsf_at_[hidden]>, David Abrahams 
<dave_at_[hidden]> writes
>Kevlin Henney <kevlin_at_[hidden]> writes:
>
>> Another distinction that needs to be made is that not all conversions
>> fit into the widening/narrowing model. Some conversions are better
>> considered as reinterpreting or translating conversions (eg lexical_cast
>> and reinterpret_cast). These are useful where some notion of subtyping
>> is not applicable, eg between int and string, as opposed to where one
>> is, eg between numeric types.
>
>I'm sympathetic to the idea that any should use implicit conversions,
>but, really, are you saying that any has a subtype relationship with
>everything it can hold?  If it did, then we could use any_cast on any
>argument type, right?

I'm not sure that I understand this wording. Is there another way of 
phrasing this or perhaps a code fragment that would illustrate the 
point?

Thanks, Kevlin.
-- 
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