Add an explicit spawn fn to TaskExecutor (#200)

src/runtime.rs

@@ -363,6 +363,50 @@ impl Runtime {
 
 // ===== impl TaskExecutor =====
 
+impl TaskExecutor {
+    /// Spawn a future onto the Tokio runtime.
+    ///
+    /// This spawns the given future onto the runtime's executor, usually a
+    /// thread pool. The thread pool is then responsible for polling the future
+    /// until it completes.
+    ///
+    /// See [module level][mod] documentation for more details.
+    ///
+    /// [mod]: index.html
+    ///
+    /// # Examples
+    ///
+    /// ```rust
+    /// # extern crate tokio;
+    /// # extern crate futures;
+    /// # use futures::{future, Future, Stream};
+    /// use tokio::runtime::Runtime;
+    ///
+    /// # fn dox() {
+    /// // Create the runtime
+    /// let mut rt = Runtime::new().unwrap();
+    /// let executor = rt.executor();
+    ///
+    /// // Spawn a future onto the runtime
+    /// executor.spawn(future::lazy(|| {
+    ///     println!("now running on a worker thread");
+    ///     Ok(())
+    /// }));
+    /// # }
+    /// # pub fn main() {}
+    /// ```
+    ///
+    /// # Panics
+    ///
+    /// This function panics if the spawn fails. Failure occurs if the executor
+    /// is currently at capacity and is unable to spawn a new future.
+    pub fn spawn<F>(&self, future: F)
+    where F: Future<Item = (), Error = ()> + Send + 'static,
+    {
+        self.inner.spawn(future).unwrap();
+    }
+}
+
 impl<T> future::Executor<T> for TaskExecutor
 where T: Future<Item = (), Error = ()> + Send + 'static,
 {