Remove the Debug and Default bounds on the Distance type

examples/knn.rs

@@ -1,6 +1,7 @@
 use vpsearch::{BestCandidate, MetricSpace};
 
 use std::collections::HashSet;
+use num_traits::Bounded;
 
 #[derive(Clone, Debug)]
 struct PointN {
@@ -45,7 +46,7 @@ impl<Item: MetricSpace<Impl>, Impl> CountBasedNeighborhood<Item, Impl> {
     fn new(item_count: usize) -> Self {
         CountBasedNeighborhood {
             max_item_count: item_count,
-            max_observed_distance: <Item::Distance as Default>::default(),
+            max_observed_distance: <Item::Distance as Bounded>::min_value(),
             distance_x_index: Vec::<(Item::Distance, usize)>::new(),
         }
     }

src/lib.rs

@@ -62,7 +62,6 @@
 
 use std::cmp::Ordering;
 use std::ops::Add;
-use std::fmt::Debug;
 use std::marker::Sized;
 use num_traits::Bounded;
 
@@ -90,7 +89,7 @@ pub trait MetricSpace<UserImplementationType = ()> {
     type UserData;
 
     /// This is a fancy way of saying it should be `f32` or `u32`
-    type Distance: Copy + PartialOrd + Bounded + Default + Debug + Add<Output = Self::Distance>;
+    type Distance: Copy + PartialOrd + Bounded + Add<Output = Self::Distance>;
 
     /**
      * This function must return distance between two items that meets triangle inequality.