# tylar [](https://crates.io/crates/tylar) [](https://travis-ci.org/Boddlnagg/tylar)
**Ty**pe-**L**evel **A**rithmetic in **R**ust.
Supports addition, subtraction, multiplication and division of (small-ish*) type-level integers.
Inspired by Björn Buckwalter's [numtype](https://github.com/bjornbm/numtype) library for Haskell. Brought to Rust thanks to multidispatch and associated types.
<sup>* Numbers in the range (–50,50) should mostly work, depending on the operations. Typechecking might be rather slow.</sup>
## Example
```rust
// N2 is the type for -2, P5 is +5, Out is the result type
// of the addition; new() creates a new instance (actually a
// no-op, since the types are zero-sized) and into() turns
// the object into an integer value, computed at compile-time
// due to static dispatch.
let result: i32 = <N2 as Add<_,P5>>::Out::new().into();
println!("-2 + 5 = {}", result); // prints `-2 + 5 = 3`
```
For more, see [examples/basics.rs](examples/basics.rs) and run `cargo run --example basics`.
Unfortunately these examples (and therefore also `cargo test`) do not work with Rust 1.0, but *tylar* itself is compatible and usable with Rust 1.0.
## License
Licensed under either of
* Apache License, Version 2.0, ([LICENSE-APACHE](LICENSE-APACHE) or http://www.apache.org/licenses/LICENSE-2.0)
* MIT license ([LICENSE-MIT](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.