Clippy warning when if then else should be the same

help
1

Here is an example where the if then else cases do the same thing but cannot be collapsed into one case:

fn max_index<T : PartialOrd>( v : &[T] ) -> usize {   
    let mut imax = v.len();
    for (i, v_i) in v.iter().enumerate() {
        if imax == v.len() {
            imax = i;   
        } else if v[imax] < *v_i {
            imax = i;
        }
    }
    imax
}
fn main() {
    let v    = vec![0, 1, 2, 3];
    let imax = max_index(&v); 
    println!( "max = {}", v[imax] );
}
1 Like
2

You can just use or, because rust short circuits. If the first condition is true, the second one will not get evaluated.

if imax == v.len() || v[imax] < *v_i {                                             
    imax = i;                                                                      
}
2 Likes
3

Another option (feel free not to use this if array indexing is more clear to you) is

if v.get(imax).is_none_or(|v_imax| v_imax < v_i) {
    imax = i;   
}

This seems theoretically preferable to me, since it's more type-safe.

4

Indeed, Clippy finds tons of such problems in my code, so I always have the solution pointed by [quote="consistent-milk12, post:2, topic:137686"]
You can just use or
[/quote]

in my pocket.