diff -r 99ad55974e62 -r d5b0e496b72f src/bisection_tree/aggregator.rs
--- a/src/bisection_tree/aggregator.rs	Mon Dec 30 15:46:28 2024 -0500
+++ b/src/bisection_tree/aggregator.rs	Mon Jan 06 20:29:25 2025 -0500
@@ -2,6 +2,7 @@
 Aggregation / summarisation of information in branches of bisection trees.
 */
 
+use serde::{Serialize, Deserialize};
 use crate::types::*;
 use crate::sets::Set;
 use crate::instance::Instance;
@@ -33,7 +34,7 @@
 }
 
 /// An [`Aggregator`] that doesn't aggregate anything.
-#[derive(Clone,Debug)]
+#[derive(Clone,Debug,Serialize,Deserialize)]
 pub struct NullAggregator;
 
 impl Aggregator for NullAggregator {
@@ -47,7 +48,7 @@
 }
 
 /// Upper and lower bounds on an `F`-valued function.
-#[derive(Copy,Clone,Debug)]
+#[derive(Copy,Clone,Debug,Serialize,Deserialize)]
 pub struct Bounds<F>(
     /// Lower bound
     pub F,