graph: Add a future plan.

* graph/src/lib.rs: Add a plan to reduce the number of
  bounds-checking.  Hopefully this makes the package more efficient.

1 files changed, 4 insertions, 0 deletions

diff --git a/graph/src/lib.rs b/graph/src/lib.rs
index 87f39c0..9e5b1cc 100644
--- a/graph/src/lib.rs
+++ b/graph/src/lib.rs
@@ -289,6 +289,10 @@ pub trait LabelGraph<T: GraphLabel>: Graph {
     where
         Self: 'a;
 
+    // TODO: Add a type that iterates through children and labels of
+    // children simultaneously.  This can reduce the number of bounds
+    // checking.
+
     /// A type that iterates through labels.
     type LabelIter<'a>: Iterator<Item = (&'a T, <Self as LabelGraph<T>>::Iter<'a>)> + 'a
     where