Example method chaining macro

chain_macro

// credit to /u/tyoverby of reddit
macro_rules! chain(
    ($inp:expr; $(. $call:ident($($e:expr),*))*) => (
        {
            let mut tmp = $inp;
            $(
                tmp.$call($($e),*);
            )*
            tmp
        }
    );
    ($inp:expr; $(. $call:ident::<$($t:ty),*>($($e:expr),*))*) => (
        {
            let mut tmp = $inp;
            $(
                tmp.$call::<$($t),*>($($e),*);
            )*
            tmp
        }
    );
);

fn main() {
    let a = vec![1u32, 2, 3];
    let b = chain!(a; .push(50));
    let c = chain!(b; 
         .push(50)
         .push(100)
         .push(150));

    assert_eq!(c, vec![1, 2, 3, 50, 50, 100, 150]);
    println!("OK")
}