libstd: remove unnecessary `to_string()` calls

3 files changed, 10 insertions, 10 deletions

diff --git a/src/libstd/collections/hash/map.rs b/src/libstd/collections/hash/map.rs
index 1fb6279d004..ef7fe48b1ad 100644
--- a/src/libstd/collections/hash/map.rs
+++ b/src/libstd/collections/hash/map.rs
@@ -1903,8 +1903,8 @@ mod test_map {
 
         let map_str = format!("{}", map);
 
-        assert!(map_str == "{1: 2, 3: 4}".to_string() || map_str == "{3: 4, 1: 2}".to_string());
-        assert_eq!(format!("{}", empty), "{}".to_string());
+        assert!(map_str == "{1: 2, 3: 4}" || map_str == "{3: 4, 1: 2}");
+        assert_eq!(format!("{}", empty), "{}");
     }
 
     #[test]
diff --git a/src/libstd/collections/hash/set.rs b/src/libstd/collections/hash/set.rs
index 9c9f23369e5..ebf7a29ad3f 100644
--- a/src/libstd/collections/hash/set.rs
+++ b/src/libstd/collections/hash/set.rs
@@ -862,7 +862,7 @@ mod test_set {
 
         let set_str = format!("{}", set);
 
-        assert!(set_str == "{1, 2}".to_string() || set_str == "{2, 1}".to_string());
-        assert_eq!(format!("{}", empty), "{}".to_string());
+        assert!(set_str == "{1, 2}" || set_str == "{2, 1}");
+        assert_eq!(format!("{}", empty), "{}");
     }
 }
diff --git a/src/libstd/collections/lru_cache.rs b/src/libstd/collections/lru_cache.rs
index 94bea37d187..638ccdb1112 100644
--- a/src/libstd/collections/lru_cache.rs
+++ b/src/libstd/collections/lru_cache.rs
@@ -446,15 +446,15 @@ mod tests {
         cache.insert(1, 10);
         cache.insert(2, 20);
         cache.insert(3, 30);
-        assert_eq!(cache.to_string(), "{3: 30, 2: 20, 1: 10}".to_string());
+        assert_eq!(cache.to_string(), "{3: 30, 2: 20, 1: 10}");
         cache.insert(2, 22);
-        assert_eq!(cache.to_string(), "{2: 22, 3: 30, 1: 10}".to_string());
+        assert_eq!(cache.to_string(), "{2: 22, 3: 30, 1: 10}");
         cache.insert(6, 60);
-        assert_eq!(cache.to_string(), "{6: 60, 2: 22, 3: 30}".to_string());
+        assert_eq!(cache.to_string(), "{6: 60, 2: 22, 3: 30}");
         cache.get(&3);
-        assert_eq!(cache.to_string(), "{3: 30, 6: 60, 2: 22}".to_string());
+        assert_eq!(cache.to_string(), "{3: 30, 6: 60, 2: 22}");
         cache.set_capacity(2);
-        assert_eq!(cache.to_string(), "{3: 30, 6: 60}".to_string());
+        assert_eq!(cache.to_string(), "{3: 30, 6: 60}");
     }
 
     #[test]
@@ -465,6 +465,6 @@ mod tests {
         cache.clear();
         assert!(cache.get(&1).is_none());
         assert!(cache.get(&2).is_none());
-        assert_eq!(cache.to_string(), "{}".to_string());
+        assert_eq!(cache.to_string(), "{}");
     }
 }