call-once

This crate provides [CallOnce], a simple, thread-safe type that can only be called successfully once:

```rust use call_once::CallOnce;

static CALL_ONCE: CallOnce = CallOnce::new();

assert!(CALLONCE.callonce().isok()); assert!(CALLONCE.callonce().iserr()); ```

For API documentation, see the [docs].

License

Licensed under either of

• Apache License, Version 2.0 (LICENSE-APACHE or http://www.apache.org/licenses/LICENSE-2.0)
• MIT license (LICENSE-MIT or http://opensource.org/licenses/MIT)

at your option.

Contribution

Unless you explicitly state otherwise, any contribution intentionally submitted for inclusion in the work by you, as defined in the Apache-2.0 license, shall be dual licensed as above, without any additional terms or conditions.