From 3d078f7c6420526d47bd50c06217b2feaab35cb2 Mon Sep 17 00:00:00 2001
From: Olaf Buddenhagen <antrik@users.sf.net>
Date: Wed, 9 Dec 2015 19:29:11 +0100
Subject: [PATCH] HashCache: Apply trait bounds on type itself, rather than
 only the impl

I don't think there is any reason to keep the container more generic
than its (only) implementation -- the constraints are necessary for this
container to work at all.

Defining the constraints on the type itself also enables use
of #[derive(Debug)].
---
 components/util/cache.rs | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/components/util/cache.rs b/components/util/cache.rs
index 7a3dcfa980f..2efb6a4e781 100644
--- a/components/util/cache.rs
+++ b/components/util/cache.rs
@@ -12,7 +12,10 @@ use std::hash::{Hash, Hasher, SipHasher};
 use std::slice::Iter;
 
 
-pub struct HashCache<K, V> {
+pub struct HashCache<K, V>
+    where K: Clone + PartialEq + Eq + Hash,
+          V: Clone,
+{
     entries: HashMap<K, V, DefaultState<SipHasher>>,
 }