Re: [Boost-users] [fusion?] [Phoenix?] Calling arbitrary method with collection of args

Subject: Re: [Boost-users] [fusion?] [Phoenix?] Calling arbitrary method with collection of args
From: Nat Goodspeed (nat_at_[hidden])
Date: 2010-03-19 13:24:35

Kim Kuen Tang wrote:

> Nat Goodspeed schrieb:
>>
>> I'm a bit surprised not to find existing support for std::vector; 
>> presumably that's been done a few times by individuals.
> 
> The size of std:::vector is not an mpl integral constant ( not known in 
> compile time). So std::vector is not a sequence in the sense of fusion. See
> http://boost-spirit.com/dl_more/fusion_v2/libs/fusion/doc/html/fusion/sequence/concepts/forward_sequence.html 

Then maybe boost::fusion::invoke() isn't what I'm looking for.

Nonetheless it comes frustratingly close: the preprocessor iteration to 
handle various arities is already done.

(In fact handling some number of C++ arities is (re)implemented in a 
surprising number of different Boost libraries.)

Presumably Boost.Python has internal machinery very like what I want, 
receiving an arbitrary sequence of Python variant objects and using them 
to populate the parameter list of some C++ callable. Of course I don't 
want to start basing production code on an undocumented implementation 
detail, though.

Still looking for a Boost feature to apply (e.g.) a std::vector of 
parameter values to a C++ callable... thanks for additional suggestions.