Re: [Boost-users] [fusion] construct a tuple's elements with arguments

From: Joel de Guzman (joel_at_[hidden])
Date: 2007-01-16 19:46:50

Yuval Ronen wrote:

> I want the ability to have the elements be constructed with any number 
> of arguments. Two is just in this specific case...
> 
>> So, I have no immediate ideas for you. If you have
>> some specific suggestions, I'm all ears.
> 
> I don't have any ideas, except maybe somehow use 
> boost::in_place_factory, but that's as specific as I can get... I do 
> think, though, that it's a valuable feature for fusion, for types that 
> don't have default constructors, or are non-copyable.

Agreed. You got me thinking. The easiest I can think of is:

     a_tuple t(apply_for_each(val1, val2,... val3));

where apply_for_each signals the constructor to construct its
elements using the supplied args.

This would be a major undertaking though since we have to do
this for all sequences in there. Perhaps there's an easier
solution. I'm saving this one for future reference.

Regards,
-- 
Joel de Guzman
http://www.boost-consulting.com
http://spirit.sf.net