Who does it better?

gistfile1.txt

Elixir

iex(3)> map = %{a: 1, b: 2, c: 3}
%{a: 1, b: 2, c: 3}

iex(4)> map |> Enum.map(fn {k, v} -> {k, v * 2} end) |> Map.new
%{a: 2, b: 4, c: 6}


Rust

use std::collections::HashMap;

fn main() {
    let map: HashMap<&str, i32> = [("a", 1), ("b", 2), ("c", 3)].iter().cloned().collect();
    dbg!(map.into_iter().map(|(k, v)| (k, v * 2)).collect::<HashMap<&str, i32>>());
}