Touch up PR 67
diff --git a/macro/src/expand.rs b/macro/src/expand.rs
index 95a6f1a..1d40419 100644
--- a/macro/src/expand.rs
+++ b/macro/src/expand.rs
@@ -602,6 +602,7 @@
         unsafe extern "C" fn #local_vector_from(this: *mut ::cxx::RustVec<#inner>, vector: *mut ::cxx::RealVector<#inner>) {
             this.as_ref().unwrap().into_vector(vector.as_mut().unwrap());
         }
+        #[doc(hidden)]
         #[export_name = #link_len]
         unsafe extern "C" fn #local_len(this: *const ::cxx::RustVec<#inner>) -> usize {
             this.as_ref().unwrap().len()