Code shared from the Rust Playground

playground.rs

fn print(n: Option<i32>) {
    // conditionally destructure
    if let Some(inner) = n {
        println!("Val: {}", inner);
    }
}

fn main() {
    print(None);
    print(Some(0));
    print(Some(5));
}

if let syntax is confusing at first but the core idea is that it's conditional let.

In the example inner is assigned only when n is not None