Once

This #![no_std] crate provides an assert_has_not_been_called! macro that panics if the surrounding function is called twice. Useful for initialization functions.

Documentation

Example

#[macro_use]
extern crate once;

fn init() {
    assert_has_not_been_called!("the init function must only be called {}", "once");
}

fn main() {
    init();
    // init(); // "the init function must only be called once"
}

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.