Trait itertools::groupbylazy::KeyFunction

trait KeyFunction<A> {
    type Key;

    // Required method
    fn call_mut(&mut self, arg: A) -> Self::Key;
}

A trait to unify FnMut for ChunkBy with the chunk key in IntoChunks

Required Associated Types

type Key

Required Methods

fn call_mut(&mut self, arg: A) -> Self::Key

Implementors

impl<A> KeyFunction<A> for ChunkIndex

type Key = usize

impl<A, K, F> KeyFunction<A> for F

where F: FnMut(A) -> K + ?Sized,

type Key = K