# Tagged union pointers
## What is it?
##### This library is unstable and may contain bugs!
A safe library for tagged union pointers. This library supports putting up to 8 `Packable3` types in a 64-bit word. A type can implement `Packable3` if it supports a bijection to a 61-bit number. The supported operations are packing, unpacking, unpacked references for matching and mutation.
Provided types are `()`, `bool`, `u16`, `u32`, `f32`, `&'a T'`, `Rc<T>`,`Box<T>`, `*T`, `*mut T`.
## Example
```
type ThinVal = Packed<Box<u64>, Box<u64>, f32, u32, bool>;
#[test]
fn test_example() {
let mut y : ThinVal = Unpacked::C(1.6f32).pack();
match *y.unpack_mut() {
Unpacked::A(ref mut b) => **b += 1,
Unpacked::B(ref mut b) => **b += 5,
Unpacked::C(ref mut f) => {*f += 4.8f32},
Unpacked::D(ref mut u) => *u += 2,
Unpacked::E(ref mut b) => *b ^= true,
_ => panic!()
}
println!("{:?}", y.unpack());
}
```
## Planned features
* Generalisations for variadic number of bits. (Generic heavy code using Peano.)
* NAN-boxing.
* Some documentation.
* Move Packable implementations to other file.
* Provide derived std traits: Clone, Copy, Eq, PartialEq, PartialOrd, Ord, Debug, Display.
## Installation
Add this to your Cargo.toml:
[dependencies]
tagged_ptr = "0.1"
and this to your crate root:
extern crate tagged_ptr;
## Changelog
* 0.1.0 Added 64-bit tagged union pointer without documentation.
## License
Dual-licensed to be compatible with the Rust project.
Licensed under the Apache License, Version 2.0 http://www.apache.org/licenses/LICENSE-2.0 or the MIT license http://opensource.org/licenses/MIT, at your option. This file may not be copied, modified, or distributed except according to those terms.