

[](https://crates.io/crates/init-hook)
[](https://docs.rs/init-hook)
# Init Hook
This crate allows registering functions for guaranteed initialization during main
### Example
```rust
use std::sync::atomic::{AtomicUsize, Ordering};
static COUNTER: AtomicUsize = AtomicUsize::new(0);
// Register function to be called exactly once during init
#[init_hook::call_on_init]
fn init_once() {
COUNTER.fetch_add(1, Ordering::Release);
}
// Registered functions can also be unsafe
#[init_hook::call_on_init]
unsafe fn init_once_unchecked() {
COUNTER.fetch_add(1, Ordering::Release);
}
fn main() {
// This is enforced by a pre-main assertion to always be included exactly once
init_hook::init!();
assert_eq!(COUNTER.load(Ordering::Acquire), 2);
}
```
### Platform support
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#### License
<sup>
Licensed under either of <a href="LICENSE-APACHE">Apache License, Version
2.0</a> or <a href="LICENSE-MIT">MIT license</a> at your option.
</sup>
<br>
<sub>
Unless you explicitly state otherwise, any contribution intentionally submitted
for inclusion in this crate by you, as defined in the Apache-2.0 license, shall
be dual licensed as above, without any additional terms or conditions.
</sub>