Expand description
Auto Convert Enums
This crate provides a proc macro that generates From impls for unnamed enum fields that have a type.
Ever get tired of writing the same From impls to enable using ? on some Result types? This crate is for you!
This is useful for enums that are used as a wrapper for a collecting multiple errors into one big enum.
Example
#[macro_use] extern crate ace_it;
#[derive(Debug)]
#[ace_it]
enum Error {
Io(std::io::Error),
ParseInt(std::num::ParseIntError),
ParseFloat(std::num::ParseFloatError),
}After this, Error has three From impls:
- From<std::io::Error> for Error
- From<std::num::ParseIntError> for Error
- From<std::num::ParseFloatError> for Error
Now you can use ? on any of these types and get an Error back.
use std::io::Read;
fn read_int<R: Read>(reader: &mut R) -> Result<i32, Error> {
let mut buf = String::new();
reader.read_to_string(&mut buf)?;
Ok(buf.parse()?)
}