Provide a function Hash::NoShareKeys::apply to disable sharing of hash keys on the specified hash (reference).
See test.pl for a usage example.
Memory consumption on a single hash with one million keys (tested on a Linux Mint 18 system with self-compiled perl 5.28.0, unthreaded):
- with key sharing: size=80666224
- without key sharing: size=56666224
- with key sharing: ~0.42s
- without key sharing: ~0.36s