On Sunday, 27 September 2020 at 14:23:11 UTC, H. S. Teoh wrote:
No. Modifying a container while iterating over it is, in general, a bad idea (unless the container is designed to be used that way, but even then, such removal is generally restricted), because it often leads to highly counterintuitive results. In the case of AA's, removing an element may lead to a rehashing, which reorders elements, and your iteration may miss some elements or repeat some elements or terminate prematurely. Even without a rehashing, you may encounter inconsistent behaviours, like some elements going "missing".
I believe it's high time we start thinking about detecting these violations at compile-time. I recall it's in the spec somewhere so we should start a deprecation process at least for AAs.
