Jasperav / enum_const_value

Constant values for enums with associated types

Enum const value

A derive macro that will add const values for enum cases, even enums with associated types. When dealing with an enum with associated types, the macro creates a new enum with the const values.

Usage

[dependencies]
enum_const_value = "0.1.0"

Now in your project, add the following:

use enum_const_value::EnumConstValue;

and use the derive macro on an enum

#[derive(EnumConstValue)]
enum MyEnum {
    SomeI32(i32),
    SomeString(String)
}

Now, you can use use the const_value() method on an enum case like so:

#[test]
fn test_my_enum() {
    assert_eq!(0, MyEnum::SomeI32(1).const_value());
    assert_eq!(1, MyEnum::SomeString("MyString".to_string()).const_value());

    assert_eq!(0, MyEnumConstValue::SomeI32.value());
    assert_eq!(1, MyEnumConstValue::SomeString.value());
}

TODO

• Custom enum case values (can be done by adding attributes)
• Custom derived enum name (is currently always $ENUMNAME$ConstValue)

License

^{Licensed under either of Apache License, Version 2.0 or MIT license at your option.}
_{Unless you explicitly state otherwise, any contribution intentionally submitted for inclusion in this crate by you, as defined in the Apache-2.0 license, shall be dual licensed as above, without any additional terms or conditions.}