[visit] add FilterNode impls for &FixedBitSet and &HashSet
It's sometimes easier to pass in a reference to a bitset or hashset while
using it as a temporary node filter. Previously the only other way to do
this was to use a closure.
diff --git a/src/visit/filter.rs b/src/visit/filter.rs
index 866194d..22beb00 100644
--- a/src/visit/filter.rs
+++ b/src/visit/filter.rs
@@ -47,6 +47,25 @@
}
}
+// Can't express these as a generic impl over all references since that would conflict with the
+// impl for Fn.
+impl<N> FilterNode<N> for &FixedBitSet
+ where FixedBitSet: VisitMap<N>
+{
+ fn include_node(&self, n: N) -> bool {
+ self.is_visited(&n)
+ }
+}
+
+impl<N, S> FilterNode<N> for &HashSet<N, S>
+ where HashSet<N, S>: VisitMap<N>,
+{
+ fn include_node(&self, n: N) -> bool {
+ self.is_visited(&n)
+ }
+}
+
+
/// A node-filtering graph adaptor.
#[derive(Copy, Clone, Debug)]
pub struct NodeFiltered<G, F>(pub G, pub F);
