properly seal

Author: molpopgen

src/table_column.rs

@@ -10,10 +10,13 @@ impl<T> std::ops::Index<usize> for OpaqueTableColumn<'_, T> {
     }
 }
 
-trait NewTypeMarker: TryInto<usize, Error = crate::TskitError> {}
+mod private {
+    pub trait NewTypeMarker: TryInto<usize, Error = crate::TskitError> {}
+    pub trait TableColumnMarker {}
+}
 
-impl NewTypeMarker for crate::EdgeId {}
-impl NewTypeMarker for crate::NodeId {}
+impl private::NewTypeMarker for crate::EdgeId {}
+impl private::NewTypeMarker for crate::NodeId {}
 
 impl<T> std::ops::Index<crate::SizeType> for OpaqueTableColumn<'_, T> {
     type Output = T;
@@ -25,7 +28,7 @@ impl<T> std::ops::Index<crate::SizeType> for OpaqueTableColumn<'_, T> {
 
 impl<I, T> std::ops::Index<I> for OpaqueTableColumn<'_, T>
 where
-    I: NewTypeMarker,
+    I: private::NewTypeMarker,
 {
     type Output = T;
     fn index(&self, index: I) -> &Self::Output {
@@ -37,16 +40,19 @@ pub trait TableColumn<I, T>:
     std::ops::Index<I, Output = T>
     + std::ops::Index<usize, Output = T>
     + std::ops::Index<crate::SizeType, Output = T>
+    + private::TableColumnMarker
 {
     fn as_slice(&self) -> &[T];
     fn get(&self, at: usize) -> Option<&T>;
     fn get_with_id(&self, at: I) -> Option<&T>;
     fn get_with_size_type(&self, at: crate::SizeType) -> Option<&T>;
 }
 
+impl<T> private::TableColumnMarker for OpaqueTableColumn<'_, T> {}
+
 impl<I, T> TableColumn<I, T> for OpaqueTableColumn<'_, T>
 where
-    I: NewTypeMarker,
+    I: private::NewTypeMarker,
 {
     fn as_slice(&self) -> &[T] {
         self.0