Code shared from the Rust Playground

playground.rs

fn main() {
    let mut x = 41;
    x ^= 1;
    
    for i in 0..(std::mem::size_of::<usize>()*8) {
        if x & (1 << i) == 0 { x ^= 1 << (i+1); } else { break; }
    }
    
    println!("{}", x);
}