Function copy_sha256 

pub async fn copy_sha256<'a, R, W>(
    reader: &'a mut R,
    writer: &'a mut W,
) -> Result<(u64, Sha256)>
where
    R: AsyncRead + Unpin + ?Sized,
    W: AsyncWrite + Unpin + ?Sized,

Available on crate feature async only.

Asynchronously copies the entire contents of a reader into a writer while hashing.