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# unchecked-index
Unchecked indexing through the regular index syntax.
Using a wrapper type that requires an `unsafe` block to create.
- crates.io: https://crates.io/crates/unchecked-index
- travis: https://travis-ci.org/bluss/unchecked-index
*Note:* All unchecked indexing here is actually “checked” with *debug
assertions* when they are enabled (they are off by default in release
builds). This is a feature! Debug checking does **not** make your code safe,
but it helps finding bugs in `unsafe` code. Test your code responsibly.
## Example
```rust
use unchecked_index::unchecked_index;
/// unsafe because: trusts the permutation to be correct
unsafe fn apply_permutation<T>(perm: &mut [usize], v: &mut [T]) {
debug_assert_eq!(perm.len(), v.len());
// use unchecked (in reality, debug-checked) indexing throughout
let mut perm = unchecked_index(perm);
for i in 0..perm.len() {
let mut current = i;
while i != perm[current] {
let next = perm[current];
// move element from next to current
v.swap(next, current);
perm[current] = current;
current = next;
}
perm[current] = current;
}
}
```
## How to contribute:
- Fix a bug or implement a new thing
- Include tests for your new feature
- Make a pull request
## Recent Changes
- 0.2.2
- The crate is now always `no_std`.
- 0.2.1
- Improve the (debug) assertion messages; fix a typo and always include
the relevant quantities (start, end, length)
- 0.2.0
- Add support for unchecked indexing with ranges (“slicing”)
- Add two free functions, `get_unchecked` and `get_unchecked_mut`
- 0.1.1
- Add `Copy` impl (for shared slices)
- 0.1.0
- Initial release
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