Centril

use std::thread::{self, JoinGuard};
use std::option::Option;
use std::marker::Send;

fn callback(v: usize) -> usize { v * 2 }

type CB = Fn(usize) -> usize + Sync + Send;
type Callback = Box<CB>;

struct S<'a> {

Centril

#![feature(core)]
#![feature(std_misc)]

use std::thread::{Thread, JoinGuard};

fn callback(v: usize) -> usize { v * 2 }

struct S {
    cb: Box<Fn(usize) -> usize + Send>,
}

Centril

/**
 * Creates an object where each property is composed from
 * an element of keys (key) and the value from callback(key).
 *
 * @param  {array} keys The array of keys.
 * @param  {function} [callback=_.identity] The callback(key) that returns the object:s values.
 * @return {object} Returns an object composed of the given keys and callback(key) for values.
 */
_.objectMap = function(keys, callback) {
  callback = callback || _.identity;