Michael Lee

This isn't really a review, more of a context dump, but it looks like the problem has to do with narrowing unions containing None. Minimized repro: ```python class SymbolTableNode: pass...

If we assume the type checker has reasonable good dead code analysis capabilities, we could get a solution that's pretty similar to the one C++ has for free by combining...

@jstasiak -- I think overriding specific parts of `--strict` is actually currently supported. For example, I can suppress the return-any errors by doing `mypy --strict --no-warn-return-any blah.py`. Somewhat tangentially: maybe...

Hmm, I wonder if it might be possible to improve the error handling of the "whole expression inference" algorithm. Basically, it seems to me that there are only four ways...

> Such constraint can't get into the list initially, I didn't clarify this, sorry. I think we should "dig through" the type components until we get a bare variable on...

Alas, this is a legitimate unsafe overlap -- the unsafeness stems from how bools are subtypes of ints in Python. Basically, we get an unsafe overlap if we try running...

Hmm, I think you might be right -- it looks like this is a legitimate bug after all! Here's a simpler repro: ```python from typing import overload @overload def foo(b:...