Re: [boost] [fusion] Re: more help with unfused_typed (previously off-list)

From: Tobias Schwinger (tschwinger_at_[hidden])
Date: 2007-07-17 14:41:52

Christian Holmquist wrote:
> To me it would be reasonable that unfused_typed, given its name, only
> generated the operator to create exactly the sequence type provided. I was
> surprised it didn't at first, but since it was clearly documented how to
> avoid this behaviour I didn't think too much about it. If this feature
> requires extra tweaks, wouldn't it be easier to avoid it? 

That might be an interesting option for 'unfused_typed'.

But the concern is not about a particular feature of 'unfused_type' -- 
error handling might have gotten worse for all 'unfused_*' adapters.

> Is it some
> particular case you have in mind where one would want to to
> default-initialize parts of the sequence?

BTW: There is no default initialization of Sequence elements. If there 
are less arguments you get a shorter Sequence.

Enabling the resulting function (object) to pose as a function with 
default arguments and allowing argument patterns (such as: (key, value, 
default)) were the reasons for making that adapter implicitly variadic.

Also, all other 'unfused_*' adapters are inherently variadic (for which 
this property is pretty much self-evident).

Regards,
Tobias