introduce custom FromRequest traint for conversion into Reply

src/httpcodes.rs

@@ -3,8 +3,7 @@
 use http::StatusCode;
 
 use body::Body;
-use route::Reply;
-use route::RouteHandler;
+use route::{Reply, RouteHandler, FromRequest};
 use httprequest::HttpRequest;
 use httpresponse::{HttpResponse, HttpResponseBuilder};
 
@@ -74,6 +73,12 @@ impl<S> RouteHandler<S> for StaticResponse {
     }
 }
 
+impl FromRequest for StaticResponse {
+    fn from_request(self, _: HttpRequest) -> Reply {
+        Reply::response(HttpResponse::new(self.0, Body::Empty))
+    }
+}
+
 impl From<StaticResponse> for HttpResponse {
     fn from(st: StaticResponse) -> Self {
         st.response()