src/test/ui/structs-enums/functional-struct-upd.rs

// run-pass
#[derive(Debug)]
struct Foo {
    x: isize,
    y: isize
}

pub fn main() {
    let a = Foo { x: 1, y: 2 };
    let c = Foo { x: 4, .. a};
    println!("{:?}", c);
}