Macro u256 

macro_rules! u256 {
    ($($body:tt)*) => { ... };
}

A macro to construct 256-bit U256 unsigned integer from literals.

Examples:

use fastnum::{u256, U256};

const N: U256 = u256!(100);
let x = u256!(1);
assert!(u256!(0).is_zero());
println!("{x}");