udec512

Macro udec512 

Source
macro_rules! udec512 {
    ($($body:tt)*) => { ... };
}
Expand description

A macro to construct 512-bit unsigned UD512 decimal from literals in compile time.

Const-evaluated in compile time macro-helper can be used for definitions of constants or variables whose value is known in compile time.

§Examples:

Basic usage:

use fastnum::*;

const N: UD512 = udec512!(1.23456789);
assert!(!N.is_zero());

let num = udec512!(0);
assert!(num.is_zero());

const A: UD512 = udec512!(5);
const B: UD512 = udec512!(1_000);
const C: UD512 = A.div(B);

assert_eq!(C, udec512!(0.005));

§Static assertions:

// The below example will fail to compile, as the function will panic at compile time:
use fastnum::{udec512, UD512}

// Gives a compile error of "error[E0080]: evaluation of constant value failed...
// the evaluated program panicked at 'attempt to parse decimal from string containing invalid digit'",
const N: UD512 = udec512!(A1.23456789);

This allows you to perform all the necessary checks such as potentialy overflow or calculation accuracy loss and others at the compile time. Protect from unexpected errors in runtime.