Features from optional dependencies

ha-ndarray implicit feature

Enables ha-ndarray

ha-ndarray:

A hardware-accelerated n-dimensional array

rjwt implicit feature

Enables rjwt

rjwt:

A recursive Javascript Web Token with support for ECDSA

txfs implicit feature

Enables txfs

txfs:

A cached transactional filesystem layer over tokio::fs

txn_lock implicit feature

Enables txn_lock

txn_lock:

Utilities to support transactional versioning