Add C-not exported comment.

Author: tnull

lightning/src/routing/scoring.rs

@@ -261,7 +261,7 @@ impl ReadableArgs<u64> for FixedPenaltyScorer {
 
 /// [`Score`] implementation that uses a dynamic penalty.
 ///
-/// (C-not exported)
+/// (C-not exported) as we don't implement function bounds mapping yet.
 pub struct DynamicPenaltyScorer<F>
 where
 	F: Fn(u64, &NodeId, &NodeId, ChannelUsage) -> u64,