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

From: Eric Niebler (eric_at_[hidden])
Date: 2007-06-15 10:50:52

Tobias Schwinger wrote:
> Tobias Schwinger wrote:
> 
>>         // [...] tricky nullary case with default ctor detection
>>         // omitted for simplicity
>>
> 
> Doh! It's not possible to detect default constructibility, correct?
> 
> 
> So we'd have to declare it as
> 
>      template<typename T, typename DefaultConstructible = mpl::false_>
>      struct constructor;

No. If the interface is "construct<T>(sequence)", then you can dispatch 
on the size of the sequence. You'd only try to default construct when 
you pass an empty sequence.

-- 
Eric Niebler
Boost Consulting
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