impl Debug (1) derive where possible and sensible

Author: phimuemue

src/adaptors/coalesce.rs

@@ -137,7 +137,7 @@ where
     }
 }
 
-#[derive(Clone)]
+#[derive(Clone, Debug)]
 pub struct DedupEq;
 
 impl<T: PartialEq> DedupPredicate<T> for DedupEq {
@@ -186,7 +186,7 @@ where
 pub type DedupByWithCount<I, Pred> =
     CoalesceBy<I, DedupPredWithCount2CoalescePred<Pred>, (usize, <I as Iterator>::Item)>;
 
-#[derive(Clone)]
+#[derive(Clone, Debug)]
 pub struct DedupPredWithCount2CoalescePred<DP>(DP);
 
 impl<DP, T> CoalescePredicate<T, (usize, T)> for DedupPredWithCount2CoalescePred<DP>

src/adaptors/map.rs

@@ -1,7 +1,7 @@
 use std::iter::FromIterator;
 use std::marker::PhantomData;
 
-#[derive(Clone)]
+#[derive(Clone, Debug)]
 #[must_use = "iterator adaptors are lazy and do nothing unless consumed"]
 pub struct MapSpecialCase<I, F> {
     iter: I,
@@ -108,7 +108,7 @@ impl<T: Into<U>, U> MapSpecialCaseFn<T> for MapSpecialCaseFnInto<U> {
     }
 }
 
-#[derive(Clone)]
+#[derive(Clone, Debug)]
 pub struct MapSpecialCaseFnInto<U>(PhantomData<U>);
 
 /// Create a new [`MapInto`] iterator.

src/adaptors/mod.rs

@@ -477,7 +477,7 @@ pub trait MergePredicate<T> {
     fn merge_pred(&mut self, a: &T, b: &T) -> bool;
 }
 
-#[derive(Clone)]
+#[derive(Clone, Debug)]
 pub struct MergeLte;
 
 impl<T: PartialOrd> MergePredicate<T> for MergeLte {

src/duplicates_impl.rs

@@ -122,6 +122,7 @@ mod private {
     }
 
     /// Apply the identity function to elements before checking them for equality.
+    #[derive(Debug)]
     pub struct ById;
     impl<V> KeyMethod<V, V> for ById {
         type Container = JustValue<V>;
@@ -152,6 +153,7 @@ mod private {
         fn value(self) -> V;
     }
 
+    #[derive(Debug)]
     pub struct KeyValue<K, V>(K, V);
     impl<K, V> KeyXorValue<K, V> for KeyValue<K, V> {
         fn key_ref(&self) -> &K {
@@ -165,6 +167,7 @@ mod private {
         }
     }
 
+    #[derive(Debug)]
     pub struct JustValue<V>(V);
     impl<V> KeyXorValue<V, V> for JustValue<V> {
         fn key_ref(&self) -> &V {

src/kmerge_impl.rs

@@ -111,7 +111,7 @@ pub trait KMergePredicate<T> {
     fn kmerge_pred(&mut self, a: &T, b: &T) -> bool;
 }
 
-#[derive(Clone)]
+#[derive(Clone, Debug)]
 pub struct KMergeByLt;
 
 impl<T: PartialOrd> KMergePredicate<T> for KMergeByLt {

src/tuple_impl.rs

@@ -77,7 +77,7 @@ impl<T> ExactSizeIterator for TupleBuffer<T>
 /// An iterator that groups the items in tuples of a specific size.
 ///
 /// See [`.tuples()`](crate::Itertools::tuples) for more information.
-#[derive(Clone)]
+#[derive(Clone, Debug)]
 #[must_use = "iterator adaptors are lazy and do nothing unless consumed"]
 pub struct Tuples<I, T>
     where I: Iterator<Item = T::Item>,