Well, I'm not sure what the “y.atan2(x)” thing is reasoned to be in Rust, but it sure doesn't look like C's manual unboxing and plain function calls. Not magic, I guess―just looks pretty much like good old OOP, which I'm being told it's not.
I suppose the “Same(x)” thing caught me by surprise―dunno, though, if it's built-in magical syntax or again something OOPy: in Python, ‘Some’ would likely be a class implementing a special method ‘__match__’.
Method calls are syntax sugar in Rust; it compiles to the same code as atan2(y, x). The only difference is it will auto ref for you in the method style. You can call it either way if you prefer. Those are just regular floats, not objects.
Some is an enum constructor that’s in the prelude, so it’s just automatically imported. It’s a library type, nothing specially built into the language.
I suppose the “Same(x)” thing caught me by surprise―dunno, though, if it's built-in magical syntax or again something OOPy: in Python, ‘Some’ would likely be a class implementing a special method ‘__match__’.