Merge pull request #322 from AlisCode/aliscode/321/fix-async-examples

#321 Fix async examples by feature-gating Command implementations + A…

1 files changed, 52 insertions, 0 deletions

diff --git a/futures/src/command.rs b/futures/src/command.rs
index d4f99b82..063e9b68 100644
--- a/futures/src/command.rs
+++ b/futures/src/command.rs
@@ -27,6 +27,7 @@ impl<T> Command<T> {
     /// Creates a [`Command`] that performs the action of the given future.
     ///
     /// [`Command`]: struct.Command.html
+    #[cfg(not(target_arch = "wasm32"))]
     pub fn perform<A>(
         future: impl Future<Output = T> + 'static + Send,
         f: impl Fn(T) -> A + 'static + Send,
@@ -36,9 +37,23 @@ impl<T> Command<T> {
         }
     }
 
+    /// Creates a [`Command`] that performs the action of the given future.
+    ///
+    /// [`Command`]: struct.Command.html
+    #[cfg(target_arch = "wasm32")]
+    pub fn perform<A>(
+        future: impl Future<Output = T> + 'static,
+        f: impl Fn(T) -> A + 'static + Send,
+    ) -> Command<A> {
+        Command {
+            futures: vec![Box::pin(future.map(f))],
+        }
+    }
+
     /// Applies a transformation to the result of a [`Command`].
     ///
     /// [`Command`]: struct.Command.html
+    #[cfg(not(target_arch = "wasm32"))]
     pub fn map<A>(
         mut self,
         f: impl Fn(T) -> A + 'static + Send + Sync,
@@ -62,6 +77,30 @@ impl<T> Command<T> {
         }
     }
 
+    /// Applies a transformation to the result of a [`Command`].
+    ///
+    /// [`Command`]: struct.Command.html
+    #[cfg(target_arch = "wasm32")]
+    pub fn map<A>(mut self, f: impl Fn(T) -> A + 'static) -> Command<A>
+    where
+        T: 'static,
+    {
+        let f = std::rc::Rc::new(f);
+
+        Command {
+            futures: self
+                .futures
+                .drain(..)
+                .map(|future| {
+                    let f = f.clone();
+
+                    Box::pin(future.map(move |result| f(result)))
+                        as BoxFuture<A>
+                })
+                .collect(),
+        }
+    }
+
     /// Creates a [`Command`] that performs the actions of all the given
     /// commands.
     ///
@@ -85,6 +124,7 @@ impl<T> Command<T> {
     }
 }
 
+#[cfg(not(target_arch = "wasm32"))]
 impl<T, A> From<A> for Command<T>
 where
     A: Future<Output = T> + 'static + Send,
@@ -96,6 +136,18 @@ where
     }
 }
 
+#[cfg(target_arch = "wasm32")]
+impl<T, A> From<A> for Command<T>
+where
+    A: Future<Output = T> + 'static,
+{
+    fn from(future: A) -> Self {
+        Self {
+            futures: vec![future.boxed_local()],
+        }
+    }
+}
+
 impl<T> std::fmt::Debug for Command<T> {
     fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         f.debug_struct("Command").finish()