returns

List

example

import {L} from 'ts-toolbelt'

type test0 = L.Concat<[1, 2], [3, 4]> // [1, 2, 3, 4]
type test1 = L.Concat<[1, 2], [[3], 4]> // [1, 2, [3], 4]
type test2 = L.Concat<[1, 2], number[]> // [1, 2, ...number[]]
type test3 = L.Concat<readonly [1, 2], readonly [3]> // [1, 2, 3]