aFilter(
  arr: T[], 
  cb: (value: T, index: number) => Promise<boolean>
): Promise<Partial<T[]>>

import { aFilter } from "@opentf/std";
 
aFilter([], async (value, index) => {});

const arr = [1, 2, 3, 4, 5];
 
function isEven(n) {
  return new Promise((resolve) => {
    resolve(n % 2 === 0);
  });
}
 
const filteredArr = await aFilter(arr, async (n) => await isEven(n));
 
console.log(filteredArr); //=> [2, 4]