If let not an expression?

I just came to know if let. Just a quick question: is it right that it is – other than a match – just to execute some side effects?

Note to self: either think before asking or drink more coffee :wink:

Of course a single if let without an else has to evaluate to (). By adding an else one can return "proper" types, e.g.

let o = Some(42);
let y = if let Some(42) = o { "42" } else { "0" };