v2: Mark `NULL` public
This will be used by external call handler implementations
@@ -69,4 +69,5 @@ pub type Error = libc::c_int;
/// Result type returned by functionality exposed by this crate.
pub type Result<T> = core::result::Result<T, Error>;
-pub(crate) const NULL: usize = usize::MAX;
+/// Internal representation of a null pointer or [`Option::None`] value in the sallyport block.
+pub const NULL: usize = usize::MAX;
