It's like once-cell, except you set the value twice.
I don't actually use this crate, since I figured out in the course of building it that I could just use a different pattern with OnceCell. Go figure! I'm still happy to accept pull requests, however, and will respond to issues while they exist in my github inbox.
In particular, I don't really remember most of the implementation details of this crate. I know I tried halfheartedly to add a new nightly feature, but since I gave up on that it wound up just being more noise for the already overworked rust maintainers. Sorry!
Licensed under Apache 2.0 or MIT, at your option.