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From: Steven Watanabe (steven_at_[hidden])
Date: 2006-12-14 20:36:57


"Korcan Hussein" wrote:
> "Steven Watanabe " wrote:
>> >Do you intend to make boost::any a typedef then?
> That would do it unless there is some non-obvious ambiguity that this
> may cause.

Not that I know of.

> Basically what i meant was you have 4 cases of: cosntant visitor
> visits constant and non-constant visitee non-constant visitor visits
> constant and non-constant visitee constant visitee accepts cosntant &
> non-constant visitor non-constant visitee accepts cosntant &
> non-constant visitor


>> >For this last I don't think there is a good non-intrusive solution.
> Are you talking about the complete solution or catch-all part? i don't
> see exactly how this is an intrusive solution so please elaborate/clarify.

It isn't. I was thinking specifically about dynamic_any.

>> >If the default is to throw an exception then it effectively limits the
>> >contained type to those enumerated. In this case it is probably better to
>> >use variant in the first place.
> I don't see what the problem is since a user can override the default
> or later extend there original visitor to support new (set) type(s),
> as well as override the definition of the old supported types if
> he/she wishes.

I don't quite understand. Would I extend it statically or dynamically?

> This solution seems to be much better than type casting (for every
> type wanted) & type switching code that you have to do with
> boost::any::. If no one likes the idea of a default catch-all/generic
> visit and have a better alternative then i'm open to it since this
> isn't set in stone and isn't diffcult to change since the
> implementation is so trivial :) Actually when i think about it the
> "catch-all" isn't even really need/necessary, the original reason why
> i put it in in the first place was as a constrast to generic visits of
> with boost::variant visitors.

You still need a catch-all even if it is not exposed to the user, don't you?

> Anyways it looks as if no one is interested, even just to make a
> comment of any form :( Thanks Korcan Hussien.

In Christ,
Steven Watanabe

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