[Python-ideas] generic code and dependent types

[Neal Becker]

I'm interested in the proposals for adding type annotation.  Coming from some 
experience with generic code in c++, one of the difficult issues has been 
reasoning about dependent types in generic code.

In general, we need to be able to declare a type via an arbitrary metafunction

some_metafunction<T>::type F (...

It is also useful to be able to write something like:

typedef typeof (int() * float()) my_type;

I wonder if any of the proposals will be able to handle this sort of algebra on 
types?  I think it's needed to truly support generic code.