From 495b07666ca02135d0b1071d398ea597dc88ce0c Mon Sep 17 00:00:00 2001
From: Vurich <jackefransham@gmail.com>
Date: Wed, 6 Dec 2017 18:02:35 +0100
Subject: [PATCH 1/2] Get key reference from set/map

---
 src/map.rs | 8 ++++++++
 src/set.rs | 6 ++++++
 2 files changed, 14 insertions(+)

diff --git a/src/map.rs b/src/map.rs
index c7e5eca..3d436ff 100644
--- a/src/map.rs
+++ b/src/map.rs
@@ -146,6 +146,14 @@ where
         }
     }
 
+    /// Returns the value corresponding to the key.
+    #[inline]
+    pub fn get_key(&self, key: K) -> Option<&K> {
+        let hash = Self::hash_key(&key);
+
+        self.find_slot(key, hash).get().map(|node| &node.key)
+    }
+
     /// Returns the value corresponding to the key.
     #[inline]
     pub fn get(&self, key: K) -> Option<V> {
diff --git a/src/set.rs b/src/set.rs
index aab6afe..04f61af 100644
--- a/src/set.rs
+++ b/src/set.rs
@@ -55,6 +55,12 @@ where
         self.map.insert(arena, item, ());
     }
 
+    /// Gets a reference to the existing value in the set, if it exists
+    #[inline]
+    pub fn get(&self, key: I) -> Option<&I> {
+        self.map.get_key(key)
+    }
+
     /// Returns `true` if the set contains a value.
     #[inline]
     pub fn contains(&self, item: I) -> bool {

From ee4745df6e99371d5766c49077debb303045fb40 Mon Sep 17 00:00:00 2001
From: Vurich <jackefransham@gmail.com>
Date: Wed, 6 Dec 2017 18:05:42 +0100
Subject: [PATCH 2/2] Implement `Default` for set/map

---
 src/map.rs | 10 ++++++++++
 src/set.rs |  9 +++++++++
 2 files changed, 19 insertions(+)

diff --git a/src/map.rs b/src/map.rs
index 3d436ff..0320d94 100644
--- a/src/map.rs
+++ b/src/map.rs
@@ -50,6 +50,16 @@ where
     last: CopyCell<Option<&'arena MapNode<'arena, K, V>>>,
 }
 
+impl<'arena, K, V> Default for Map<'arena, K, V>
+where
+    K: 'arena,
+    V: 'arena + Copy,
+{
+    fn default() -> Self {
+        Self::new()
+    }
+}
+
 impl<'arena, K, V> Map<'arena, K, V>
 where
     K: 'arena,
diff --git a/src/set.rs b/src/set.rs
index 04f61af..ad15c22 100644
--- a/src/set.rs
+++ b/src/set.rs
@@ -12,6 +12,15 @@ pub struct Set<'arena, I: 'arena> {
     map: Map<'arena, I, ()>,
 }
 
+impl<'arena, I> Default for Set<'arena, I>
+where
+    I: 'arena,
+{
+    fn default() -> Self {
+        Self::new()
+    }
+}
+
 impl<'arena, I> Set<'arena, I>
 where
     I: 'arena,