libcollections: String + &str

src/libcollections/string.rs

@@ -855,6 +855,8 @@ impl<'a, S: Str> Equiv<S> for String {
     }
 }
 
+// NOTE(stage0): Remove impl after a snapshot
+#[cfg(stage0)]
 #[experimental = "waiting on Add stabilization"]
 impl<S: Str> Add<S, String> for String {
     fn add(&self, other: &S) -> String {
@@ -864,6 +866,14 @@ impl<S: Str> Add<S, String> for String {
     }
 }
 
+#[cfg(not(stage0))]  // NOTE(stage0): Remove cfg after a snapshot
+impl<'a> Add<&'a str, String> for String {
+    fn add(mut self, other: &str) -> String {
+        self.push_str(other);
+        self
+    }
+}
+
 impl ops::Slice<uint, str> for String {
     #[inline]
     fn as_slice_<'a>(&'a self) -> &'a str {