You're right - thank you for this constructive criticism. The post was originally written as a DIP (D Improvement Proposal), and arguably suffers a little because of that.
Since Cython compiles to C++, it can use C++ templates directly, without the need for creating aliases to the specific instantiations you're gonna use. As far as I understand, you'll still have to write Cython bindings, though:
https://cython.readthedocs.io/en/latest/src/userguide/wrappi...
Walter got a bit confused here - what he's describing is the owner/borrow system he's proposed to compete with Rust. This is unrelated to named parameters.