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 Hash::Ordered::Benchmarks.