use anything::{Anything, Nothing};

pub fn func_1() -> Result<(),Anything> {
    Err(())?;
    Ok(())
}

pub fn func_2() -> Result<(),Anything> {
    Err("Hello World")?;
    Ok(())
}

pub fn func_3() -> Result<(),Nothing> {
    Err("Hello World")?;
    Ok(())
}

fn func_4() -> Anything {
    let a= std::io::Error::last_os_error();
    Anything::from(a)
}

fn func_5() -> Result<(), Anything> {
    fn func_5a() -> Result<(), Anything> {
        fn func_5b() -> Result<(), Anything> {
            fn func_5c() -> Result<(), Anything> {
                fn func_5d() -> Result<(), Anything> {
                    Err("Hello World")?;
                    Ok(())
                }
                func_5d()?;
                Ok(())
            }
            func_5c()?;
            Ok(())
        }
        func_5b()?;
        Ok(())
    }
    func_5a()?;
    Ok(())
}

#[test]
pub fn test() {
    println!("func1: {:?}\n", func_1().unwrap_err());
    println!("func2: {:?}\n", func_2().unwrap_err());
    println!("func3: {:?}\n", func_3().unwrap_err());
    println!("func4: {:?}\n", func_4());
    println!("func5: {:?}\n", func_5().unwrap_err());
}