Derives an enum of same-variant pairs of another enum.
# Installation
```sh
cargo add samevariant
```
# Use
Define an enum and use this derive macro:
```
#[samevariant(pub ABCSameVariant)]
pub enum ABC {
A,
B,
C(i32),
}
```
It generates a new enum that looks like:
```
enum ABCSameVariant<'l> {
Nonmatching(&'l ABC, &'l ABC),
A,
B,
C(&'l i32, &'l i32),
}
impl ABCSameVariant {
fn pairs<'l>(a: &'l ABC, b: &'l ABC) -> ABCSameVariant<'l> {
...
}
}
```
If the base enum has a variant `Nonmatching` it will be prefixed by the original enum name (like `ABCNonmatching`).
Only simple and tuple variants are supported, struct-like variants will result in an error.