docs reference

src/foreign_macros/externfn_impl.rs

@@ -19,6 +19,8 @@ use crate::{atomic_impl, atomic_redirect};
 /// reference to self and a closure. This can be used in conjunction with
 /// [atomic_impl] and [atomic_redirect] to normalize the argument automatically
 /// before using it.
+/// 
+/// See [atomic_impl] for an example.
 #[macro_export]
 macro_rules! externfn_impl {
   ($typ:ident, $next_atomic:expr) => {