`TryRwLock` is a lightweight readers-writer lock implemented with atomics that does not support
blocking.
A readers-writer lock allows multiple readers or one writer to access it at a time.
[`try-lock`](https://crates.io/crates/try-lock) and
[`try-mutex`](https://crates.io/crates/try-mutex) provide a similar function to this, but
implement mutexes not readers-writer locks.
License: MIT OR Apache-2.0