Re: [boost] [fusion] unpack into constructor?

From: Eric Niebler (eric_at_[hidden])
Date: 2007-06-14 10:53:26

Hartmut Kaiser wrote:
>  
> dan marsden wrote:
> 
>>> I have a Fusion sequence. I want to create an object of type T using 
>>> the elements of the sequence as arguments to the 
>> constructor. Is there 
>>> an easy way? I can't tell my looking at the docs. I looked 
>> at the stuff 
>>> in fusion/functional and couldn't find what I was looking for.
> 
> Isn't that exactly what a Phoenix actor does? 

Hartmut, are you saying this functionality has no place in Fusion?

>> I don't think we've got anything that supports this directly 
>> at the moment.
>> Is the sort of thing you are looking for?
>>
>> fused_ctor<T> fc;
>> T t = fc(sequence);
>>
>> Where fused_ctor::operator()(Seq const&) breaks up the 
>> sequence into args for the T ctor.

Yes, that's the thing.

>> If thats the sort of thing, I think we should have something 
>> like this, I can cook something up over the next few days, 
>> once I've worked through a bit of my backlog :)
>>
>> Of course I may have missed an existing feature, which my 
>> co-authors might pick me up on...

Thanks, Dan. FWIW, I have my own solution for this now, so there's no 
rush. But I'm sure it'd come in handy eventually.

-- 
Eric Niebler
Boost Consulting
www.boost-consulting.com