[dozzie]

> Why would you care about selecting the branch in compile time?

I wouldn't. Pattern matching is primarly a conditional, that's why I focused on if-else.

> We're talking about language features semantically equivalent to pattern matching, and, turns out, there are none.

Why would you think that pattern matching revolves around compile-time guarantees? It does not. It's primarly a conditional, everything else is an optional, additional effect. You can have pattern matching in dynamically typed languages (Lisp, Erlang).