> > > Does anybody know how to implement type traits that will allow me to > check > > > whether argument type T is instance od template A. Particularly I am > > > interested in mpl sequences. I.e.: > > > > > > is_instance_of<T,mpl::list>::value > > > > Check out boost/lambda/detail/is_instance_of.hpp
> > 1. Could we make it an "official" type trait? Sure. John, do you agree? > 2. Could we make if work with no template template support? > I was thinking about: > is_instance_of<T,mpl::list<_> >::value > But I do not understand how mpl::lambda is working yet, so it could be > complete nonsense. I'm not aware of a solution without template template parameters. > 3. Why there is no namely is_instance_of version without number of template > parameters explicitly specified. > Could not you deduce it automatically? The second argument is a template template parameter, and I think that type must be spelled out entirely, thus I can't see a way to get rid of the n in is_instance_of_n. I hope someone can prove me wrong. > 4. Why it is limited only to 4 template parameters? Well, 4 met the needs of LL, and it never got extended as it wasn't made to an 'official' type trait. Note that there are other limitations, templates with non-type parameters are not supported. Jaakko _______________________________________________ Unsubscribe & other changes: http://lists.boost.org/mailman/listinfo.cgi/boost