rustc: implement and use Default on more types.

3 files changed, 25 insertions, 23 deletions

diff --git a/src/librustc_data_structures/Cargo.toml b/src/librustc_data_structures/Cargo.toml
index 79f073d643d..5b3dd38adf2 100644
--- a/src/librustc_data_structures/Cargo.toml
+++ b/src/librustc_data_structures/Cargo.toml
@@ -9,7 +9,7 @@ path = "lib.rs"
 crate-type = ["dylib"]
 
 [dependencies]
-ena = "0.9.3"
+ena = "0.10.1"
 log = "0.4"
 rustc_cratesio_shim = { path = "../librustc_cratesio_shim" }
 serialize = { path = "../libserialize" }
diff --git a/src/librustc_data_structures/snapshot_map/mod.rs b/src/librustc_data_structures/snapshot_map/mod.rs
index f8663cd4fd4..0b42cb1eddd 100644
--- a/src/librustc_data_structures/snapshot_map/mod.rs
+++ b/src/librustc_data_structures/snapshot_map/mod.rs
@@ -23,6 +23,18 @@ pub struct SnapshotMap<K, V>
     undo_log: Vec<UndoLog<K, V>>,
 }
 
+// HACK(eddyb) manual impl avoids `Default` bounds on `K` and `V`.
+impl<K, V> Default for SnapshotMap<K, V>
+    where K: Hash + Clone + Eq
+{
+    fn default() -> Self {
+        SnapshotMap {
+            map: Default::default(),
+            undo_log: Default::default(),
+        }
+    }
+}
+
 pub struct Snapshot {
     len: usize,
 }
@@ -35,17 +47,6 @@ enum UndoLog<K, V> {
     Noop,
 }
 
-impl<K, V> Default for SnapshotMap<K, V>
-    where K: Hash + Clone + Eq
-{
-    fn default() -> Self {
-        SnapshotMap {
-            map: FxHashMap::default(),
-            undo_log: vec![],
-        }
-    }
-}
-
 impl<K, V> SnapshotMap<K, V>
     where K: Hash + Clone + Eq
 {
diff --git a/src/librustc_data_structures/transitive_relation.rs b/src/librustc_data_structures/transitive_relation.rs
index e1318eb54d5..fd5dfab9e61 100644
--- a/src/librustc_data_structures/transitive_relation.rs
+++ b/src/librustc_data_structures/transitive_relation.rs
@@ -42,6 +42,18 @@ pub struct TransitiveRelation<T: Clone + Debug + Eq + Hash> {
     closure: Lock<Option<BitMatrix<usize, usize>>>,
 }
 
+// HACK(eddyb) manual impl avoids `Default` bound on `T`.
+impl<T: Clone + Debug + Eq + Hash> Default for TransitiveRelation<T> {
+    fn default() -> Self {
+        TransitiveRelation {
+            elements: Default::default(),
+            map: Default::default(),
+            edges: Default::default(),
+            closure: Default::default(),
+        }
+    }
+}
+
 #[derive(Copy, Clone, PartialEq, Eq, PartialOrd, Ord, Hash, RustcEncodable, RustcDecodable, Debug)]
 struct Index(usize);
 
@@ -51,17 +63,6 @@ struct Edge {
     target: Index,
 }
 
-impl<T: Clone + Debug + Eq + Hash> Default for TransitiveRelation<T> {
-    fn default() -> TransitiveRelation<T> {
-        TransitiveRelation {
-            elements: vec![],
-            map: FxHashMap::default(),
-            edges: vec![],
-            closure: Lock::new(None),
-        }
-    }
-}
-
 impl<T: Clone + Debug + Eq + Hash> TransitiveRelation<T> {
     pub fn is_empty(&self) -> bool {
         self.edges.is_empty()