ref: d359a98ab9cfc42de66ad35333bd6d6c0571b7ca
dir: /lib/std/test/iterutil.myr/
use std
const main = {
var n
n = 0
for (x, i) : std.byenum([1,3,5,7,9][:])
std.assert(x == n, "invalid enum idx {}", x)
std.assert(i == n*2 + 1, "invalid enum val {}", i)
n++
;;
n = 0
for (a, b) : std.byzip([0,2,4,6,8][:], [2,4][:])
std.assert(a == n*2, "invalid val from a: {}", a)
std.assert(b == n*2 + 2, "invalid val from b: {}", b)
n++
;;
n = 0
for x : std.byreverse([3, 2, 1, 0][:])
std.assert(x == n, "invalid reversed value {}, expected {}", x, n)
n++
;;
}