I’m trying to define a large number in a Sway unit test, but getting the following issue:

```
280 | let expected: u256 = 160149899619106589403934712464197979;
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ int literal out of range
```

How can I define large integers?

diyahir
November 20, 2023, 9:31am
2
```
//! A 256-bit unsigned integer type.
library;
use ::assert::*;
use ::convert::From;
use ::result::Result::{self, *};
use ::u128::U128;
use ::math::Power;
/// Left shift a `u64` and preserve the overflow amount if any.
fn lsh_with_carry(word: u64, shift_amount: u64) -> (u64, u64) {
let right_shift_amount = 64 - shift_amount;
let carry = word >> right_shift_amount;
let shifted = word << shift_amount;
(shifted, carry)
}
/// Right shift a `u64` and preserve the overflow amount if any.
fn rsh_with_carry(word: u64, shift_amount: u64) -> (u64, u64) {
let left_shift_amount = 64 - shift_amount;
```

This file has been truncated. show original

```
pub struct U256 {
/// The most significant 64 bits of the `U256`.
a: u64,
/// The 65-128th most significant bits of the `U256`.
b: u64,
/// The 129-192nd most significant bits of the `U256`.
c: u64,
/// The 193-256th most significant bits of the `U256`.
d: u64,
}
```

I don’t think it can just take the raw number, I believe you need to decompose your number into 4 64 bit pieces and then reconstruct it

I’m trying to use the native `u256`

, not the `U256`

library.

I worded around it by converting to hex and using the `0x1234u256`

notation. But would still be nice to have decimal literals as well.

FossilFrank:

`u256`

Yes, @FossilFrank , that is the correct way to do it. I will bring this up with the team to discuss implementing decimal literals.

system
Closed
December 11, 2023, 6:46pm
6
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