Macro u128 

macro_rules! u128 {
    ($($body:tt)*) => { ... };
}

A macro to construct 128-bit U128 unsigned integer from literals.

Examples:

use fastnum::{u128, U128};

const N: U128 = u128!(100);
let x = u128!(1);
assert!(u128!(0).is_zero());
println!("{x}");