[yoklov]

This isn't the issue I'm describing at all.

E.g. if I missed a bounds check, and access past the end of a `Foo[]`, it would be typed as `Foo` (and not `Foo | undefined`), but really be `undefined.

Consider this code.

    var foos: Foo[] = [new Foo()];
    foos[1].bar();

foos[1] will be undefined (since it's past the end of the array) but will typecheck as a Foo.

Obviously it's bad if I forget a bounds check, but it's similarly bad if I forgot a null check.

Of course, I understand why this issue exists, but it is an issue.