I'm trying to use enum variants to capture data which is heterogeneous in nature (has different collections of fields) but which is of the same "type" from a protocol perspective. However, I'm not sure how to implement subtype-specific methods and traits. Here is a minimal example of how I can create an enumeration of Data and I can use enum variant constructors to specify the types, but if I implement a trait on the variant, calling that function is not something I've figured out how to do.
use std::fmt;
enum Data {
N(NData),
S(SData),
}
struct NData {
numeric: u32,
}
impl fmt::Display for NData {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
write!(f, "{}", self.numeric)
}
}
struct SData {
stringy: Vec<String>,
}
fn main() {
let d_n: Data = Data::N(NData { numeric: 0x0 });
let n = NData { numeric: 0xff };
// Fails, fmt::Display not implemented for Data
println!("{}", d_n);
// Just fine!
println!("{}", n);
}
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