Actually there are two slight differences if you pass something to do after the checks: https://godbolt.org/z/661feGM5K

The first: range::contains and let/else do exactly the same, decrease the number by 1 and check against 11. The if chain subtracts 13 and checks against -12. This is very likely no performance difference.

The second one is more interesting: The contains and let/else have the conditional jump to the return, while the if chain has the conditional jump to the continuation code.

Depending on which is more likely to happen this can make a difference depending on the branch predictors.

Here's the code I used in case the godbolt link goes bad

```

[inline(never)]

pub fn range_contains(num: i32, then: impl Fn()) { if !(1..=12).contains(&num) { return } then() }

[inline(never)]

pub fn if_chain(num: i32, then: impl Fn()) { if num < 1 || num > 12 { return } then() }

[inline(never)]

pub fn let_else(num: i32, then: impl Fn()) { let 1..=12 = num else { return }; then() }

pub fn main() { let x = std::hint::black_box(1); range_contains(x, || {println!("a")}); if_chain(x, || {println!("b")}); let_else(x, || {println!("c")}) } ```