When does rewriting happen for unordered associative containers?

Question

I found this in the standard as a post-condition for the rehash function in unordered associative containers:

Message: a.bucket_count ()> a.size () / a.max_load_factor () and a.bucket_count ()> = n. (n is the number of buckets in the container)

Can I assume that this means that automatic repeat clicks start when one of the above conditions is true for all implementations? Or, are there any implementation options that can be decided when you need to rephrase, and the above only applies to the rehash function?

Answer 1

The implementation should contain load_factor() <= max_load_factor() and load_factor() == size() / bucket_count() . Thus, automatic repeat playback can occur during insert to keep the load factor invariant.

Despite the fact that load_factor() cannot exceed max_load_factor() , I do not think that there is a guarantee that re-writing will not be performed during insertion, even if you can prove that this invariant will not be violated.

Definition for max_load_factor :

Returns a positive number that the container is trying to keep the load ratio less than or equal to. The container automatically increases the number of buckets as needed to keep the load factor below that number.