Trait enumscribe::TryUnscribe

pub trait TryUnscribe: Sized {
    // Required method
    fn try_unscribe(to_unscribe: &str) -> Option<Self>;
}

Trait for converting from a string to an enum, or None if the conversion fails.

Like all of the traits provided by enumscribe, this should not be implemented manually; use #[derive(TryUnscribe)] provided by the enumscribe_derive crate instead.

Annotating a variant with #[enumscribe(case_insensitive)] will cause case insensitive matching to be used for that variant. If it is omitted, matching will be case sensitive.

When deriving this trait, you may specify the string that should map to a particular variant by annotating it with #[enumscribe(str = "foo")]. If this is omitted, the name of the variant will be used instead.

use enumscribe::TryUnscribe;

#[derive(TryUnscribe, PartialEq, Eq, Debug)]
enum Airport {
    #[enumscribe(str = "LHR", case_insensitive)]
    Heathrow,
    #[enumscribe(str = "LGW")]
    Gatwick,
}

assert_eq!(Airport::try_unscribe("LHR"), Some(Airport::Heathrow));
assert_eq!(Airport::try_unscribe("lhr"), Some(Airport::Heathrow));

assert_eq!(Airport::try_unscribe("LGW"), Some(Airport::Gatwick));
assert_eq!(Airport::try_unscribe("lgw"), None);

assert_eq!(Airport::try_unscribe("STN"), None);
assert_eq!(Airport::try_unscribe("stn"), None);

Required Methods

fn try_unscribe(to_unscribe: &str) -> Option<Self>

Converts the given string to an enum variant, or None if the conversion was not successful.

The given string is matched against the #[enumscribe(str = "...")] attribute for each variant to determine which variant to return. If there was no successful match, the variant marked with #[enumscribe(other)] will be returned instead. If there is no variant marked with #[enumscribe(other)], then None will be returned.

Object Safety

This trait is not object safe.

Implementors