> when you do unwrap() you're saying the Result should NEVER fail
Returning a Result by definition means the method can fail.
Returning a Result by definition means the method can fail.
No more than returning an int by definition means the method can return -2.
What? Returning an int does in fact mean that the method can return -2. I have no idea what your argument is with this, because you seem to be disagreeing with the person while actually agreeing with them.
What? No it doesn't.
fn square(n: i32) -> i32 {
n * n
}
Though in this case it's more like knowing that the specific way you call the function in foo.rs will never get back a -2.
fn bar(n: i32, allow_negative: bool) -> i32 {
let new = n * 2;
if allow_negative || new >= 0 { new } else { 0 }
}
bar(x, false)Some call points to a function that returns an int will never return -2.
Sometimes you know things the type system does not know.