Derive Macro strum_macros::IntoStaticStr
source · [−]#[derive(IntoStaticStr)]
{
// Attributes available to this derive:
#[strum]
}
Expand description
Implements From<MyEnum> for &'static str
on an enum.
Implements From<YourEnum>
and From<&'a YourEnum>
for &'static str
. This is
useful for turning an enum variant into a static string.
The Rust std
provides a blanket impl of the reverse direction - i.e. impl Into<&'static str> for YourEnum
.
use strum_macros::IntoStaticStr;
#[derive(IntoStaticStr)]
enum State<'a> {
Initial(&'a str),
Finished,
}
fn verify_state<'a>(s: &'a str) {
let mut state = State::Initial(s);
// The following won't work because the lifetime is incorrect:
// let wrong: &'static str = state.as_ref();
// using the trait implemented by the derive works however:
let right: &'static str = state.into();
assert_eq!("Initial", right);
state = State::Finished;
let done: &'static str = state.into();
assert_eq!("Finished", done);
}
verify_state(&"hello world".to_string());