add clone impls for combinator services

src/service/and_then.rs

@@ -26,6 +26,19 @@ where
     }
 }
 
+impl<A, B> Clone for AndThen<A, B>
+where
+    A: Service + Clone,
+    B: Service<Request = A::Response, Error = A::Error>,
+{
+    fn clone(&self) -> Self {
+        AndThen {
+            a: self.a.clone(),
+            b: self.b.clone(),
+        }
+    }
+}
+
 impl<A, B> Service for AndThen<A, B>
 where
     A: Service,

src/service/apply.rs

@@ -27,6 +27,22 @@ where
     }
 }
 
+impl<T, F, R, Req> Clone for Apply<T, F, R, Req>
+where
+    T: Service + Clone,
+    T::Error: Into<<R::Future as Future>::Error>,
+    F: Fn(Req, &mut T) -> R + Clone,
+    R: IntoFuture,
+{
+    fn clone(&self) -> Self {
+        Apply {
+            service: self.service.clone(),
+            f: self.f.clone(),
+            r: PhantomData,
+        }
+    }
+}
+
 impl<T, F, R, Req> Service for Apply<T, F, R, Req>
 where
     T: Service,

src/service/fn_state_service.rs

@@ -33,6 +33,23 @@ where
     }
 }
 
+impl<S, F, Req, Resp, Err, Fut> Clone for FnStateService<S, F, Req, Resp, Err, Fut>
+where
+    S: Clone,
+    F: Fn(&mut S, Req) -> Fut + Clone,
+    Fut: IntoFuture<Item = Resp, Error = Err>,
+{
+    fn clone(&self) -> Self {
+        FnStateService {
+            f: self.f.clone(),
+            state: self.state.clone(),
+            req: marker::PhantomData,
+            resp: marker::PhantomData,
+            err: marker::PhantomData,
+        }
+    }
+}
+
 impl<S, F, Req, Resp, Err, Fut> Service for FnStateService<S, F, Req, Resp, Err, Fut>
 where
     F: Fn(&mut S, Req) -> Fut,

src/service/map.rs

@@ -25,11 +25,24 @@ where
     }
 }
 
+impl<A, F, R> Clone for Map<A, F, R>
+where
+    A: Service + Clone,
+    F: Fn(A::Response) -> R + Clone,
+{
+    fn clone(&self) -> Self {
+        Map {
+            a: self.a.clone(),
+            f: self.f.clone(),
+            r: marker::PhantomData,
+        }
+    }
+}
+
 impl<A, F, R> Service for Map<A, F, R>
 where
     A: Service,
-    F: Fn(A::Response) -> R,
-    F: Clone,
+    F: Fn(A::Response) -> R + Clone,
 {
     type Request = A::Request;
     type Response = R;

src/service/map_err.rs

@@ -25,6 +25,20 @@ where
     }
 }
 
+impl<A, F, E> Clone for MapErr<A, F, E>
+where
+    A: Service + Clone,
+    F: Fn(A::Error) -> E + Clone,
+{
+    fn clone(&self) -> Self {
+        MapErr {
+            a: self.a.clone(),
+            f: self.f.clone(),
+            e: marker::PhantomData,
+        }
+    }
+}
+
 impl<A, F, E> Service for MapErr<A, F, E>
 where
     A: Service,