Stop writing pub is_whatever(&self) -> bool for your enums by hand -- it's a pain! Just #[derive(is_enum_variant)] instead!

Add derive_is_enum_variant to your crate's Cargo.toml:

[dependencies]
derive_is_enum_variant = "<insert-latest-version-here>"

And then add #[derive(is_enum_variant)] to your enum definitions:

#[macro_use]
extern crate derive_is_enum_variant;

#[derive(is_enum_variant)]
pub enum Pet {
    Doggo,
    Kitteh,
}

fn main() {
    let pet = Pet::Doggo;

    assert!(pet.is_doggo());
    assert!(!pet.is_kitteh());
}

By default, the predicates are named is_snake_case_of_variant_name. You can use any name you want instead with #[is_enum_variant(name = "..")]:

#[derive(is_enum_variant)]
pub enum Pet {
    #[is_enum_variant(name = "is_real_good_boy")]
    Doggo,
    Kitteh,
}

let pet = Pet::Doggo;
assert!(pet.is_real_good_boy());

If you don't want to generate a predicate for a certain variant, you can use #[is_enum_variant(skip)]:

#[derive(is_enum_variant)]
pub enum Errors {
    Io(::std::io::Error),

    #[doc(hidden)]
    #[is_enum_variant(skip)]
    __NonExhaustive,
}

Licensed under either of

• Apache License, Version 2.0 (LICENSE-APACHE or http://www.apache.org/licenses/LICENSE-2.0)
• MIT license (LICENSE-MIT or http://opensource.org/licenses/MIT)

at your option.

See CONTRIBUTING.md for hacking!

Unless you explicitly state otherwise, any contribution intentionally submitted for inclusion in the work by you, as defined in the Apache-2.0 license, shall be dual licensed as above, without any additional terms or conditions.

License: Apache-2.0/MIT