This class wraps around a hash containing integer numbers, where the
values are strings. Hashes are also available as implementation of the
ArrayAccess interface.
Hashes can also be iterated over with foreach as the Iterator interface is
implemented as well. The order of which elements are returned in is not
guaranteed.
Disables the use of PHP's internal memory manager for internal
set structures. With this option enabled, internal allocations will not
count towards the memory_limit settings.
Selects to not use a hashing function, but merely use a modulo to
find the bucket list index. This is not faster than normal hashing, and
gives more collisions.