add extend to snapshot-vec

Author: nikomatsakis

Cargo.toml

@@ -4,7 +4,7 @@ description = "Union-find, congruence closure, and other unification code. Based
 license = "MIT/Apache-2.0"
 homepage = "https://github.com/nikomatsakis/ena"
 repository = "https://github.com/nikomatsakis/ena"
-version = "0.7.0"
+version = "0.7.1"
 authors = ["Niko Matsakis <niko@alum.mit.edu>"]
 
 [features]

src/snapshot_vec.rs

@@ -225,6 +225,14 @@ impl<D: SnapshotVecDelegate> ops::IndexMut<usize> for SnapshotVec<D> {
     }
 }
 
+impl<D: SnapshotVecDelegate> Extend<D::Value> for SnapshotVec<D> {
+    fn extend<T>(&mut self, iterable: T) where T: IntoIterator<Item=D::Value> {
+        for item in iterable {
+            self.push(item);
+        }
+    }
+}
+
 impl<D: SnapshotVecDelegate> Clone for SnapshotVec<D>
     where D::Value: Clone, D::Undo: Clone,
 {