fn_once 0.1.0

This library provides a convenient derive macro for a once function.
Documentation 
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# **`fn_once`**

This library provides a convenient derive macro for a once function.

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[ci-badge]: https://github.com/just-do-halee/fn_once/actions/workflows/ci.yml/badge.svg
[crates-badge]: https://img.shields.io/crates/v/fn_once.svg?labelColor=383636
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[ci-url]: https://github.com/just-do-halee/fn_once/actions
[twitter-url]: https://twitter.com/do_halee
[crates-url]: https://crates.io/crates/fn_once
[license-url]: https://github.com/just-do-halee/fn_once

```toml
fn_once = "0.1.0"
```

## **`How to use,`**

```rust
use fn_once::once;

#[once]
fn print_once(name: &str) {
    println!("Hello! {}!", name);
}

#[once(or = { number })] // or = { ... }
fn add_one_once(number: u32) -> u32 {
    count + 1
}

fn main() {
    print_once("World"); // print "Hello! World!"
    print_once("foo"); // no effect

    let mut number = 0;
    number = add_one_once(number); // 0 + 1 -> 1
    number = add_one_once(number); // no effect -> 1
    number = add_one_once(number); // no effect -> 1
    assert_eq!(number, 1);
}
```