Return Rust generator from function

return-generator.rs

use genawaiter::{sync::gen, yield_, Generator};

type MyGen = Box<dyn Generator<Yield = i32, Return = i32>>;

fn make_generator() -> MyGen {
  let gen = gen!({
    yield_!(1);
    yield_!(2);
    yield_!(3);
    4
  });
  Box::new(gen)
}