Description:

This module implements an ordered hash, meaning that it associates keys
with values like a Perl hash, but keeps the keys in a consistent order.
Because it is implemented as an object and manipulated with method calls,
it is much slower than a Perl hash. This is the cost of keeping order.

However, compared to other *ordered* hash implementations, Hash::Ordered is
optimized for getting and setting individual elements and is generally
faster at most other tasks as well. For specific details, see the
Hash::Ordered::Benchmarks manpage.