lib: keys in maps and sets are not nullable

[nit.git] / src / metamodel / partial_order.nit

diff --git a/src/metamodel/partial_order.nit b/src/metamodel/partial_order.nit
index 9fe3ba3..fd9a8bb 100644 (file)
--- a/src/metamodel/partial_order.nit
+++ b/src/metamodel/partial_order.nit
@@ -19,7 +19,7 @@ package partial_order
 
 # Handles partial ordered sets (ie hierarchies)
 # Thez are built by adding new element at the bottom of the hierarchy
-class PartialOrder[E]
+class PartialOrder[E: Object]
 special Collection[E]
        # Elements
        var _elements: Map[E, PartialOrderElement[E]]
@@ -186,7 +186,7 @@ special Collection[E]
        end
 end
 
-class PartialOrderElement[E]
+class PartialOrderElement[E: Object]
        # The partial order where belong self
        readable var _order: PartialOrder[E]