Macro doe::bfn

macro_rules! bfn {
    ($v:expr) => { ... };
}

implments Bfn struct and bfn! macro for Box<dyn Fn()> trait object

fn main() {
    use doe::DebugPrint;
    use doe::bfn;
    use doe::Bfn;
    #[derive(Debug)]
    struct Demo<'a>{
        name:&'a str
    }
    let f0 = bfn!(||{println!("ok");});
    f0.call();
    fn func()->Demo<'static>{
        let d = Demo{name: "andrew"};
        d
    }
    let f1 = bfn!(func);
    f1.call().dprintln();

    fn sum()->usize{
        9+89
    }
    let f2 = Bfn::new(Box::new(sum));//or bfn!(sum);
    f2.call().dprintln();
}