Code shared from the Rust Playground

playground.rs

#![allow(unused)]

macro_rules! nested {
    ($x:expr) => { ($x) };
    ($x:expr, $($rest:expr),+) => {
        (
            $x,
            nested!($($rest),*)
        )
    };
}

fn main() {
    let result = nested!(1, 2, 3);
    println!("{:?}", result);
}