PEP 3107 and stronger typing (note: probably a newbie question)

[Paul Rubin]

"Diez B. Roggisch" <deets at nospam.web.de> writes:
> Sure. But which class of programs are decidable? There's lot's of
> research going on with model checking and the like. But AFAIK, the
> consensus is that the very moment you allow recursive types, the
> type-checking is either incomplete, or possibly
> non-deterministic. Which makes then the compiler hang.

Type checking is already undecidable in many mainstream languages
including C++.  Nonetheless people manage to use those languages.