into_enum provides a single macro, IntoEnum.
Enums with unique variants can derive IntoEnum to provide straight-forward From implementations.
use into_enum::IntoEnum;
#[derive(IntoEnum)]
enum MyError {
IO(std::io::Error), // impl From<std::io::Error> for MyError
Reqwest(reqwest::Error), // impl From<reqwest::Error> for MyError
Custom(crate::Error), // impl From<crate::Error> for MyError
}The macro provides the attribute into_enum(skip) to ignore a variant, in case of type conflict or unwanted conversion.
#[derive(IntoEnum)]
enum Results {
Default(u32), // impl From<u32> for Results
#[into_enum(skip)]
Special(u32), // nothing generated
Message(String), // impl From<String> for Results
}The macro also generates conversions for unit variants and tuple variants. Variants with named fields are skipped.
#[derive(IntoEnum)]
enum Numerical {
Default, // impl From<()> for Numerical
Number(u32), // impl From<u32> for Numerical
Double(u32, u32), // impl From<(u32, u32)> for Numerical
Complex { base: u32 } // Nothing generated
}The macro maintains trait bounds for generic types.