use deku::prelude::*;
use std::convert::{TryFrom, TryInto};

// Note: new `deku_derive` vs `derive`, this is needed only for structs/enums which use `temp`
#[deku_derive(DekuRead, DekuWrite)]
#[derive(PartialEq, Debug)]
struct TestStruct {
    #[deku(temp)]
    field_a: u8,
    #[deku(count = "field_a")]
    field_b: Vec<u8>,
}

fn main() {
    let test_data: Vec<u8> = [0x01, 0x02].to_vec();

    let ret_read = TestStruct::try_from(test_data.as_ref()).unwrap();
    assert_eq!(
        TestStruct {
            field_b: vec![0x02]
        },
        ret_read
    );

    let ret_write: Vec<u8> = ret_read.try_into().unwrap();
    assert_eq!(test_data[1..].to_vec(), ret_write);
}