Re: [Boost-users] [boost parameter] misusing deduced - thanks, but sill unsure about the next step

Subject: Re: [Boost-users] [boost parameter] misusing deduced - thanks, but sill unsure about the next step
From: David Abrahams (dave_at_[hidden])
Date: 2009-02-26 12:46:53

On Feb 24, 2009, at 11:29 PM, er wrote:

> David Abrahams wrote:
>> on Sun Feb 22 2009, er <erwann.rogard-AT-gmail.com> wrote:
>>> I've realized I wasn't using deduced properly. Something like this?
>>>
>>> 	typedef parameter::parameters<
>>> 		parameter::required<
>>>            parameter::deduced<tag_type>,
>>>            is_same<mpl::_1,self_type>
>>>        >
>>> 	> params;
>>>
>>> Should allow and ArgPack of the form ((tag = x)) or ((x)),  
>>> provided x is of type
>>> self_type, right?
>> Yes, that looks right to me.
>
> Thank you for your answer, but I would still need a bit of help:
>
> I'm trying to fetch an argument only by its type, not its name or  
> position.
>
> For example, I can't replace ((x)) above by say ((x,y)) where only x  
> has the desired type, because apparently, this is not a proper way  
> to form an ArgPack.

Sorry, I'm not aware of a way of forming an argument pack with /no/  
names other than by using the function call operator on a ParameterSpec.

--
David Abrahams
BoostPro Computing
http://boostpro.com