Key types

[zertyz]

Thanks for sharing the good work.

I'm looking at the C++ version:

I'd give a suggestion for you to accept more key types. double, float, int, long, ...

Also, a method for clearing the hashmap, so we can better manage unit tests.

... ah, and there is missing a method to remove members.

... keys, once inserted, cannot be updated?

-- luiz

[luispedro]

These are all good suggestions, but note that this project fulfills my current goals. So I am more than happy to review PRs, but I cannot dedicate the time right now to implementing it myself...