Can the order in associative array change when keys are not midified?

[Idan Arye via Digitalmars-d-learn]

On Thursday, 1 January 2015 at 13:39:57 UTC, Peter Alexander 
wrote:
> On Thursday, 1 January 2015 at 13:13:10 UTC, Andrej Mitrovic 
> via Digitalmars-d-learn wrote:
>> On 1/1/15, Idan Arye via Digitalmars-d-learn
>> <digitalmars-d-learn at puremagic.com> wrote:
>>> If I have an associative array and I only modify it's values,
>>> without changing the keys, can I assume that the order won't
>>> change?
>>
>> Associative arrays are not ordered at all.
>>
>> See the first note here: http://dlang.org/hash-map.html
>
> The order is unspecified, but an iteration must iterate in 
> *some* order. The question (if I've understood it correctly), 
> is whether that order of iteration changes when the keys aren't 
> changed.
>
> The spec doesn't say anything about this, although I would 
> expect in practice that the order will not change.
>
> I've added a bug to track this omission from the spec: 
> https://issues.dlang.org/show_bug.cgi?id=13923

That's right.

My use case is that I have a large AA where the values are 
numbers and the keys are strings, and I need to send it over 
network again and again. The values constantly change but the 
keys should remain the same(after an initial initialization 
process), so I don't want to always have to send the keys, which 
compose the larger part of the AA's size. If the order is fixed 
as long as the keys are fixed I can cache the keys order and send 
only the values(without having to sort them each time).