Code shared from the Rust Playground

playground.rs

fn main() {
    #[derive(Eq, PartialEq, Clone)]
    struct A { a: Vec<u8> }
    
    let a = A { a: vec![1, 2, 3] };
    let c = A { a: vec![1, 2, 3] };
    
    let mut b = vec![a.clone(), a.clone(), a];
    
    // if let Some(pos) = b.iter().position(|elt| elt == c) { // This will error out
    if let Some(pos) = b.iter().position(|elt| *elt == c) {
        let _ = b.remove(pos);
        b.push(c);
    }
}