Implement binding support for returning and accepting Promises in WebIDL.

1 files changed, 19 insertions, 0 deletions

diff --git a/components/script/dom/bindings/js.rs b/components/script/dom/bindings/js.rs
index a7ecc975129..50cae7e1f04 100644
--- a/components/script/dom/bindings/js.rs
+++ b/components/script/dom/bindings/js.rs
@@ -43,6 +43,7 @@ use std::intrinsics::type_name;
 use std::mem;
 use std::ops::Deref;
 use std::ptr;
+use std::rc::Rc;
 use style::thread_state;
 
 /// A traced reference to a DOM object
@@ -439,6 +440,18 @@ impl<T: Reflectable> LayoutJS<T> {
     }
 }
 
+/// Get an `&T` out of a `Rc<T>`
+pub trait RootedRcReference<T> {
+    /// Obtain a safe reference to the wrapped non-JS owned value.
+    fn r(&self) -> &T;
+}
+
+impl<T: Reflectable> RootedRcReference<T> for Rc<T> {
+    fn r(&self) -> &T {
+        &*self
+    }
+}
+
 /// Get an `Option<&T>` out of an `Option<Root<T>>`
 pub trait RootedReference<T> {
     /// Obtain a safe optional reference to the wrapped JS owned-value that
@@ -446,6 +459,12 @@ pub trait RootedReference<T> {
     fn r(&self) -> Option<&T>;
 }
 
+impl<T: Reflectable> RootedReference<T> for Option<Rc<T>> {
+    fn r(&self) -> Option<&T> {
+        self.as_ref().map(|root| &**root)
+    }
+}
+
 impl<T: Reflectable> RootedReference<T> for Option<Root<T>> {
     fn r(&self) -> Option<&T> {
         self.as_ref().map(|root| root.r())