Got another macro for the reverse op:
```rust
/// Syntax helper for converting primitives to multi-byte fields.
///
/// Example: `copy_le!(bytes, &self.position, 5..9);`
#[macro_export]
macro_rules! copy_le {
    ($bytes:expr, $val:expr, $range:expr) => {{
        $bytes[$range].copy_from_slice($val.to_le_bytes())
    }};
}
```