Bug 13923 – Specify guarantees on associative array iteration order volatility

Suppose I have an associative array: string[int] a = [1:"a", 2:"b", 3:"c"]; Now, associative arrays have unspecified iteration order, but suppose I iterate the array and it iterates in order {2, 1, 3}. What guarantees are provided on subsequent iterations? Specifically: * If I iterate the array again, without modifying any keys or values, or inserting, removing, or rehashing; is the iteration order guaranteed to be the same? * If I iterate the array again, with only modifying values (not keys), is the iteration order guaranteed to be the same? The spec should specify what operations may alter the iteration order, and what operations will leave it intact.

Answer to your questiones: You have no guarantees. "In particular, in a foreach loop the order in which the elements are iterated is typically unspecified." from https://dlang.org/spec/hash-map.html