Code shared from the Rust Playground

playground.rs

use std::fmt::Debug;

//trait ReturnType: Debug + Clone {}
//
//impl ReturnType for String {}
//impl ReturnType for i32 {}

#[derive(Debug)]
enum Command {
    Create,
    Get(usize),
}

#[derive(Debug)]
enum Ret {
    RetNone,
    RetStr(String),
    RetI32(i32)
}

fn handle_command(command: Command) -> Result<Ret, Box<dyn std::error::Error>> {
    match command {
        Command::Create => Ok(Ret::RetStr("new_string".to_string())),
        Command::Get(index) => Ok(Ret::RetI32(index as i32 + 1)),
    }
}

fn main() {
    let get_value = handle_command(Command::Get(1));
    println!("get_value: {:?}", get_value);
    let create_value = handle_command(Command::Create);
    println!("get_value: {:?}", create_value);

}