This library exports a trait called TagName
that exposes a
tag_name
method which is used for retrieving a name (tag) of a currently hold variant within an enum
value.
More importantly, together with TagName
trait comes a derive(TagName)
macro that can automatically implement the trait.
use tagname::TagName;
#[derive(TagName)]
enum MyTaggedUnion {
#[tag(case = "lower")]
Yes,
#[tag(case = "upper")]
No,
Maybe(usize),
}
#[test]
fn return_correct_tag_names() {
let v1 = MyTaggedUnion::Yes;
let v2 = MyTaggedUnion::No;
let v3 = MyTaggedUnion::Maybe(1);
assert_eq!(v1.tag_name(), "yes");
assert_eq!(v2.tag_name(), "NO");
assert_eq!(v3.tag_name(), "Maybe");
}