fn callback(path: Vec<(usize, usize)>) {
    print!("start");
    for x in &path {
        print!(" -> ({}, {})", x.0, x.1);
    }
    print!("\n");
}
/// Simple callback printing the path.
Simple callback printing the path.
Simple callback printing the path .
fn callback(path: Vec<(usize, usize)>) {
    print!("start");
    for x in &path {
        print!(" -> ({}, {})", x.0, x.1);
    }
    print!("\n");
}
fn callback ( path : Vec < ( usize , usize ) > ) { print ! ( " " ) ; for x in & path { print ! ( " " x 0 x 1 ) ; } print ! ( " \n " ) ; }
Simple callback printing the path.
Simple callback printing the path .
path
Vec<(usize, usize)>
path
Vec<(usize, usize)>