From 9d2636e8b0525b96c86ee47dc27379e4b9386eac Mon Sep 17 00:00:00 2001
From: nham <hamann.nick@gmail.com>
Date: Sun, 13 Jul 2014 13:02:38 -0400
Subject: [PATCH 1/2] Implement PartialOrd for HashSet

---
 src/libstd/collections/hashmap.rs | 15 ++++++++++++++-
 1 file changed, 14 insertions(+), 1 deletion(-)

diff --git a/src/libstd/collections/hashmap.rs b/src/libstd/collections/hashmap.rs
index 098e87243b69c..dc79229935d55 100644
--- a/src/libstd/collections/hashmap.rs
+++ b/src/libstd/collections/hashmap.rs
@@ -11,7 +11,8 @@
 //! Unordered containers, implemented as hash-tables (`HashSet` and `HashMap` types)
 
 use clone::Clone;
-use cmp::{max, Eq, Equiv, PartialEq};
+use cmp;
+use cmp::{max, Eq, Equiv, PartialEq, Ordering};
 use collections::{Collection, Mutable, Set, MutableSet, Map, MutableMap};
 use default::Default;
 use fmt::Show;
@@ -1499,6 +1500,18 @@ impl<T: Eq + Hash<S>, S, H: Hasher<S>> PartialEq for HashSet<T, H> {
 
 impl<T: Eq + Hash<S>, S, H: Hasher<S>> Eq for HashSet<T, H> {}
 
+impl<T: Eq + Hash<S>, S, H: Hasher<S>> PartialOrd for HashSet<T, H> {
+    #[inline]
+    fn partial_cmp(&self, other: &HashSet<T, H>) -> Option<Ordering> {
+        match (self.is_subset(other), other.is_subset(&self)) {
+            (true, true) => Some(cmp::Equal),
+            (true, false) => Some(cmp::Less),
+            (false, true) => Some(cmp::Greater),
+            (false, false) => None
+        }
+    }
+}
+
 impl<T: Eq + Hash<S>, S, H: Hasher<S>> Collection for HashSet<T, H> {
     fn len(&self) -> uint { self.map.len() }
 }

From 52192cd0d0b5bddafc4c98f254299fb7efdde238 Mon Sep 17 00:00:00 2001
From: nham <hamann.nick@gmail.com>
Date: Sun, 13 Jul 2014 14:21:00 -0400
Subject: [PATCH 2/2] Various fixes.

---
 src/libstd/collections/hashmap.rs | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/libstd/collections/hashmap.rs b/src/libstd/collections/hashmap.rs
index dc79229935d55..20c7e1c695d87 100644
--- a/src/libstd/collections/hashmap.rs
+++ b/src/libstd/collections/hashmap.rs
@@ -12,7 +12,7 @@
 
 use clone::Clone;
 use cmp;
-use cmp::{max, Eq, Equiv, PartialEq, Ordering};
+use cmp::{max, Eq, Equiv, PartialEq, PartialOrd, Ordering};
 use collections::{Collection, Mutable, Set, MutableSet, Map, MutableMap};
 use default::Default;
 use fmt::Show;
@@ -1503,7 +1503,7 @@ impl<T: Eq + Hash<S>, S, H: Hasher<S>> Eq for HashSet<T, H> {}
 impl<T: Eq + Hash<S>, S, H: Hasher<S>> PartialOrd for HashSet<T, H> {
     #[inline]
     fn partial_cmp(&self, other: &HashSet<T, H>) -> Option<Ordering> {
-        match (self.is_subset(other), other.is_subset(&self)) {
+        match (self.is_subset(other), other.is_subset(self)) {
             (true, true) => Some(cmp::Equal),
             (true, false) => Some(cmp::Less),
             (false, true) => Some(cmp::Greater),