Re: [Boost-users] [fusion] result_of

Subject: Re: [Boost-users] [fusion] result_of
From: Thomas Heller (thom.heller_at_[hidden])
Date: 2011-05-08 12:52:58

On Sunday, May 08, 2011 07:40:50 PM Robert Ramey wrote:
> I'm very interested in fusion and have been experimenting with it.
> 
> There is one thing that is currently confusing me.  (OK more than one 
> thing).
> The documentation a typical function at 
> .../fusion/sequence/concepts/associative_sequence.html
> shows valid expression
> 
> has_key<K>(s)
> 
> returning type
> 
> result_of::has_key<S, K>::type
> 
> which is OK by me.  But why doesn't fusion use:
> 
> #include <boost/result_of.hpp>
> then use boost::result_of<has_key<K>(S)>::type
> 
> which would seem to me to reduce the size of fusion
> (and the docs) by around 50%.  What am I missing
> here?

That boost::result_of does not work with plain old free functions.

> Robert Ramey