Re: [Boost-users] [Bind] arity of arbitrary object

From: Joel de Guzman (joel_at_[hidden])
Date: 2007-01-17 02:24:45

Peter Dimov wrote:
> Sohail Somani wrote:
> 
>> Hi, I've attached up something that seems to kind of maybe work in
>> g++. Don't have access to any other compiler at the moment, so I
>> can't tell you if it will work or if it is even conforming to
>> standard.
> 
> No, this doesn't quite work. It says that bind( f, _5 ) has arity 1, but the 
> correct answer is 5. Similarly, it says that bind( f, 1, 2 ) has arity 2, 
> while the correct answer is 0. You need something like (pseudocode)
> 
> arity( _bi::bind_t<R,F,L> ) :- max( arity( e ) ) for each e in L
> arity( X ) :- is_placeholder<X>::value
> 
> This could be much easier with a bind that uses a fusion tuple as L. :-)

Phoenix :)

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