# typestate-enum
A Rust macro to help build simple Typestate APIs.
## Example
The following example defines a trait ``State`` and 3 zero-sized types which
implement it: ``Ready``, ``Working``, and ``Complete``. The types can then be
used to build simple Typestate APIs.
```rust
use typestate_enum::typestate_enum;
use std::marker::PhantomData;
typestate_enum! {
pub State {
Ready,
Working,
Complete
}
}
struct Action<S: State>(PhantomData<S>);
impl<S: State> Action<S> {
fn new() -> Self {
Action::<S>(PhantomData)
}
}
impl Action<Ready> {
fn start_work(self) -> Action<Working> {
Action::new()
}
}
impl Action<Working> {
fn complete_work(self) -> Action<Complete> {
Action::new()
}
}
```