--- Benoit wrote:
Hello everyone,
Howdy!
I have been using properties quite extensively in my work. And these last days I have needed to combine properties numerous times.
By that, I mean that I have n properties p1, p2, ... pn and what I use is get( p1, get( p2, get( ..., get( pn, object ) ... ) ) ) I would very much want to make a composite property p to be used like this : get( p, object ) (most of the time, n=2, but why stop there ? :-) )
I have to tried to find such functionality but in vain so far... Does it not exist? Are there obstacles that i have not foreseen? I am thinking of something like the following:
template<class Prop1, class Prop2> struct composite_property { composite_property(Prop1 p1_, Prop2 p2_) : p1( p1_ ), p2( p2_ ) { }
Prop1 p1; Prop2 p2; };
template<class Prop1, class Prop2> typename property_traits<Prop1>::reference get(composite_property<Prop1, Prop2> comp, typename property_traits<Prop2>::reference x) { return get( comp.p1, get( comp.p2, x ) ); }
How do you all feel about this? I believe it would be very useful!
I believe that the Fusion library provides a map that possesses the functionality you need. You can wait until Boost version 1.34 is released, or you can grab a CVS snapshot in order to play with it right away. HTH, Cromwell D. Enage __________________________________________________ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com