Merge pull request #106 from H2CO3/default-tokenstream

impl Default for TokenStream
diff --git a/src/lib.rs b/src/lib.rs
index 67f8033..9930c3c 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -118,6 +118,14 @@
     }
 }
 
+/// `TokenStream::default()` returns an empty stream,
+/// i.e. this is equivalent with `TokenStream::new()`.
+impl Default for TokenStream {
+    fn default() -> Self {
+        TokenStream::new()
+    }
+}
+
 /// Attempts to break the string into tokens and parse those tokens into a token
 /// stream.
 ///
diff --git a/tests/test.rs b/tests/test.rs
index 6a06092..5d2fb85 100644
--- a/tests/test.rs
+++ b/tests/test.rs
@@ -381,3 +381,10 @@
 
     assert_eq!(expected, format!("{:#?}", tts));
 }
+
+#[test]
+fn default_tokenstream_is_empty() {
+    let default_token_stream: TokenStream = Default::default();
+
+    assert!(default_token_stream.is_empty());
+}