iter_first_max

Trait IterFirstMaxExt

Source 
pub trait IterFirstMaxExt: Iterator + Sized {
    // Provided methods
    fn first_max(self) -> Option<Self::Item>
       where Self::Item: Ord { ... }
    fn first_max_by<F>(self, f: F) -> Option<Self::Item>
       where F: FnMut(&Self::Item, &Self::Item) -> Ordering { ... }
    fn first_max_by_key<B, F>(self, f: F) -> Option<Self::Item>
       where F: FnMut(&Self::Item) -> B,
             B: Ord { ... }
}
Expand description

Iterator::max* returns the last for equal keys, this crate implements the return the first

use iter_first_max::IterFirstMaxExt as _;

let arr = [(0, 0), (1, 1), (2, 2), (2, 3), (2, 4)];
let last  = arr.iter().max_by_key(|n| n.0);
let first = arr.iter().first_max_by_key(|n| n.0);

assert_eq!(last,  Some(&(2, 4)));
assert_eq!(first, Some(&(2, 2)));

Provided Methods§

Source

fn first_max(self) -> Option<Self::Item>
where Self::Item: Ord,

Get max element, if equal, return the first equal element

Source

fn first_max_by<F>(self, f: F) -> Option<Self::Item>
where F: FnMut(&Self::Item, &Self::Item) -> Ordering,

Get max element, if equal, return the first equal element

Source

fn first_max_by_key<B, F>(self, f: F) -> Option<Self::Item>
where F: FnMut(&Self::Item) -> B, B: Ord,

Get max element, if key equal, return the first key equal element

Dyn Compatibility§

This trait is not dyn compatible.

In older versions of Rust, dyn compatibility was called "object safety", so this trait is not object safe.

Implementors§