# enum_repr_conv
`enum_repr_conv` is a proc-macro library that provides a convenient attribute-style `repr_conv()` macro to specify a primitive integer type used for representing variants of the annotated fieldless enum as values of this type.

## Description
`enum_repr_conv` bridges the gap between C-style enums and fieldless enums in Rust that can be represented using a chosen primitive integer type. It implements conversions from enum variants into integer values (infallible through [`std::convert::From`](https://doc.rust-lang.org/std/convert/trait.From.html)) and vice versa (fallible through [`std::convert::TryFrom`](https://doc.rust-lang.org/std/convert/trait.TryFrom.html)).
This functionality is provided via `repr_conv(<type>)` macro that mimics the syntax and behavior of [`repr(u*)/repr(i*)`](https://doc.rust-lang.org/nomicon/other-reprs.html#repru-repri) data layout attributes but additionally provides practical and sensible implementations of common conversion traits.
## Example
```rust
use enum_repr_conv::repr_conv;

#[repr_conv(u16)]
#[derive(Debug, PartialEq, Eq)]
enum SupportedPorts {
	FTP = 21,
	SSH, // = 22
	HTTP = 80,
	HTTPS = 443,
}

// we can get a u16 for the FTP port easily...
assert_eq!(u16::from(SupportedPorts::FTP), 21);
//... and for the SSH port too
assert_eq!(u16::from(SupportedPorts::SSH), 22);
// HTTP port is supported and so conversion succeeds
assert_eq!(SupportedPorts::try_from(80).unwrap(), SupportedPorts::HTTP);
// Gopher is not supported; who needs it in 2025?!
assert!(SupportedPorts::try_from(70).is_err());
```

## License
Licensed under [`Boost Software License, Version 1.0`](https://www.boost.org/LICENSE_1_0.txt).
