5 releases
0.2.3 | Jul 7, 2022 |
---|---|
0.2.2 | Jun 22, 2022 |
0.2.1 | Jun 22, 2022 |
0.2.0 | Jun 22, 2022 |
0.1.0 | Jun 21, 2022 |
#13 in #procmacro
38 downloads per month
Used in 4 crates
(via empty_type)
39KB
852 lines
EmptyType Derive Macro
Used to derive a corresponding Container
for an EmptyType
implementation.
Will roughly produce equivalent code to:
use empty_type::{EmptyType, Container};
struct Data {
key: String
}
#[derive(Default)]
struct OptionalData {
key: Option<String>
}
impl EmptyType for Data {
type Container = OptionalData;
fn new_container() -> Self::Container {
OptionalData {
key: None
}
}
}
impl Container for OptionalData {
type Value = Data;
fn try_open(&mut self) -> Result<Self::Value, Box<dyn std::error::Error>> {
Ok(Data {
key: self.key.open()
})
}
}
Dependencies
~1.5MB
~36K SLoC