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rustiteratormax

Is there a Rust function that returns all the maximum values of an iterator?

I have a specific use case where I need to choose the maximum element from an Iterator<Item = (i8, f64)>. If there are multiple maximum elements in the Iterator I want to randomly select a maximum element uniformly distributed.

I tried the max_by function for Iterators but it doesn't work as I need it because it always returns the last element if there a multiple maximum elements. Here the example:

fn main() {
    let v = [(-1i8, 0.4f64), (0, 0.2), (1, 0.4)];
    let max = v.into_iter().max_by(|(_, r), (_, s)| r.total_cmp(s)).unwrap(); //always returns (1, 0.4)
    println!("{:?}", max);
}

playground

I need a function which returns another Iterator over the maximum elements. Then I could choose a random element from that Iterator.

Solution

  • Not in std, but in itertools there is:

    iter.max_set();