not sure yet if any of this works, because the
technicalities of dealing with variadic types are
quite different to our LISP-style typelist processing.
The good news is that with variadic templates it is
indeed possible, to supply dynamically picked arguments
to another function taking arbitrary arguments.
This all relies on the feature to unpack argument packs,
and, more specifically, about the possiblity to "wrap"
this unpacking around interspersed function call syntax
template<size_t...i>
Xyz
do_something(MyTuple myTuple)
{
return Xyz (std::get<i> (myTuple) ... );
}
Here the '...' will be applied to the i... and then
the whole std::get-construct will be wrapped around
each element. Mind bogging, but very powerful
