Enum Ordinalize
====================
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This crates provides `create_ordinalized_enum` macro to let enums can not only get its variants' ordinal but also be constructed from an ordinal.
## Create an Ordinalized Enum
`create_ordinalized_enum` macro can create an enum and implement a `ordinal` method, as well as `from_ordinal` and `from_ordinal_unsafe` associated functions for it.
The new enum also implements `Debug`, `PartialEq`, and `Clone` traits.
```rust
#[macro_use] extern crate enum_ordinalize;
create_ordinalized_enum!(MyEnum,
Zero,
One,
Two
);
assert_eq!(2, MyEnum::Two.ordinal());
assert_eq!(Some(MyEnum::One), MyEnum::from_ordinal(1));
create_ordinalized_enum!(pub MyPublicEnum,
A,
B,
C
);
assert_eq!(2, MyPublicEnum::C.ordinal());
assert_eq!(Some(MyPublicEnum::B), MyPublicEnum::from_ordinal(1));
create_ordinalized_enum!(MySpecialEnum,
Two = 2,
Four = 4,
Eight = 8
);
assert_eq!(2, MySpecialEnum::Two.ordinal());
assert_eq!(Some(MySpecialEnum::Four), MySpecialEnum::from_ordinal(4));
```
## About an Ordinalized Enum
An ordinalized enum is always sized **isize** in order to directly **transmute** into an **isize** value, or conversely.
There is a variant named *__DotNotUse* whose ordinal is always the maximum of an **isize** value for every ordinalized enum.
If you are **100% sure** that the **isize** value can transmute into a variant of your ordinalized enum. You can use `from_ordinal_unsafe` associated function and **unsafe** keyword to speed up.
```rust
#[macro_use] extern crate enum_ordinalize;
create_ordinalized_enum!(MyEnum,
Zero,
One,
Two
);
assert_eq!(MyEnum::One, unsafe{MyEnum::from_ordinal_unsafe(1)});
```
## Crates.io
https://crates.io/crates/enum-ordinalize
## Documentation
https://docs.rs/enum-ordinalize
## License
[MIT](LICENSE)