Boost::Any ported to D

[Marcin Kuszczak]

Bruno Medeiros wrote:

> Marcin Kuszczak wrote:
>> 3. I can not compile program after putting PlaceHolder interface and
>> Holder class into Any class (like in the original approach). Is it bug or
>> am I doing something wrong?
> 
> Hum, C++ allows member(=inner) classes? Didn't know that. Are they
> static or "instance"(meaning they require an outer class context) classes?
> Recall that in D they are "instance" by default, and static on option
> only.

As I know outer class works just as namespace for inner class. So I would
say static class definitions.

> 
>> 4. Why specialization for implicitly instatiated function templates is
>> not possible? (But it is possible to use static if and is operator).
> 
> What exactly did you want to do? Is it like the issue here:
> http://d.puremagic.com/issues/show_bug.cgi?id=337 ? Are the workarounds
> there acceptable?
> 

I used workaround with static if:

Any assign(ValueType)(ValueType value) {
        static if (is(ValueType == Any)) content = value.content!=null ? 
                value.content.clone() : null;
        else content=new Holder!(ValueType)(value);
        return this;
}

but why below doesn't work?:
Any assign(ValueType)(ValueType value) {
        content=new Holder!(ValueType)(value);
        return this;
}

Any assign(ValueType : Any)(ValueType value) {
        content = value.content!=null ? value.content.clone() : null;
        return this;
}

according to documentation specialization is not permitted when using
implicit instatiation. But still don't know why...

-- 
Regards
Marcin Kuszczak
(Aarti_pl)