sample.rs

fn verify<'a>(env: NifEnv<'a>, args: &[NifTerm<'a>]) -> NifResult<NifTerm<'a>> {
    let block_number: u64 = try!(args[0].decode());
    let header_hash: &'a str = try!(args[1].decode());
    let nonce: u64 = try!(args[2].decode());

    let ethash = EthashManager::new();
    let result = ethash.compute_light(block_number, get_bytes_ref(header_hash), nonce);

    Ok((atoms::ok(), result).encode(env))
}

fn get_bytes_ref(s: &str) -> &[u8; 32] { assert!(s.len() == 32); unsafe { &*(s.as_ptr() as *const [u8; 32]) }}