How do I convert U256 to u128 in alloy?

Question

How do I convert U256 to different types using alloy primitives?

For example

let num = U256::from(42_u8);

In ethers it's simple, num.to_u128() but how to do it in alloy?

Answer 1

In alloy you use .to::< > turbofish to convert between types

    let num = U256::from(42_u8);

    let a: u128 = num.to::<u128>();
    assert_eq!(a, 42);

    let b: u64 = num.to::<u64>();
    assert_eq!(b, 42);

    let c: u32 = num.to::<u32>();
    assert_eq!(c, 42);

    let d: usize = num.to::<usize>();
    assert_eq!(d, 42);

    let e: String = num.to_string();
    assert_eq!(e, "42");

    let f: String = format_units(num, 4)?;
    assert_eq!(f, "0.0042");

This is not pretty straight forward from google search, keeping it here for future references.

Source : Github