remove generic body type in App. (#2493)

src/app.rs

@@ -1,9 +1,6 @@
-use std::{cell::RefCell, fmt, future::Future, marker::PhantomData, rc::Rc};
+use std::{cell::RefCell, fmt, future::Future, rc::Rc};
 
-use actix_http::{
+use actix_http::{body::MessageBody, Extensions, Request};
-    body::{BoxBody, MessageBody},
-    Extensions, Request,
-};
 use actix_service::{
     apply, apply_fn_factory, boxed, IntoServiceFactory, ServiceFactory, ServiceFactoryExt,
     Transform,
@@ -26,7 +23,7 @@ use crate::{
 
 /// Application builder - structure that follows the builder pattern
 /// for building application instances.
-pub struct App<T, B> {
+pub struct App<T> {
     endpoint: T,
     services: Vec<Box<dyn AppServiceFactory>>,
     default: Option<Rc<BoxedHttpServiceFactory>>,
@@ -34,10 +31,9 @@ pub struct App<T, B> {
     data_factories: Vec<FnDataFactory>,
     external: Vec<ResourceDef>,
     extensions: Extensions,
-    _phantom: PhantomData<B>,
 }
 
-impl App<AppEntry, BoxBody> {
+impl App<AppEntry> {
     /// Create application builder. Application can be configured with a builder-like pattern.
     #[allow(clippy::new_without_default)]
     pub fn new() -> Self {
@@ -51,22 +47,11 @@ impl App<AppEntry, BoxBody> {
             factory_ref,
             external: Vec::new(),
             extensions: Extensions::new(),
-            _phantom: PhantomData,
         }
     }
 }
 
-impl<T, B> App<T, B>
+impl<T> App<T> {
-where
-    B: MessageBody,
-    T: ServiceFactory<
-        ServiceRequest,
-        Config = (),
-        Response = ServiceResponse<B>,
-        Error = Error,
-        InitError = (),
-    >,
-{
     /// Set application (root level) data.
     ///
     /// Application data stored with `App::app_data()` method is available through the
@@ -365,7 +350,7 @@ where
     ///         .route("/index.html", web::get().to(index));
     /// }
     /// ```
-    pub fn wrap<M, B1>(
+    pub fn wrap<M, B, B1>(
         self,
         mw: M,
     ) -> App<
@@ -376,9 +361,16 @@ where
             Error = Error,
             InitError = (),
         >,
-        B1,
     >
     where
+        T: ServiceFactory<
+            ServiceRequest,
+            Response = ServiceResponse<B>,
+            Error = Error,
+            Config = (),
+            InitError = (),
+        >,
+        B: MessageBody,
         M: Transform<
             T::Service,
             ServiceRequest,
@@ -396,7 +388,6 @@ where
             factory_ref: self.factory_ref,
             external: self.external,
             extensions: self.extensions,
-            _phantom: PhantomData,
         }
     }
 
@@ -431,7 +422,7 @@ where
     ///         .route("/index.html", web::get().to(index));
     /// }
     /// ```
-    pub fn wrap_fn<B1, F, R>(
+    pub fn wrap_fn<F, R, B, B1>(
         self,
         mw: F,
     ) -> App<
@@ -442,12 +433,19 @@ where
             Error = Error,
             InitError = (),
         >,
-        B1,
     >
     where
-        B1: MessageBody,
+        T: ServiceFactory<
+            ServiceRequest,
+            Response = ServiceResponse<B>,
+            Error = Error,
+            Config = (),
+            InitError = (),
+        >,
+        B: MessageBody,
         F: Fn(ServiceRequest, &T::Service) -> R + Clone,
         R: Future<Output = Result<ServiceResponse<B1>, Error>>,
+        B1: MessageBody,
     {
         App {
             endpoint: apply_fn_factory(self.endpoint, mw),
@@ -457,12 +455,11 @@ where
             factory_ref: self.factory_ref,
             external: self.external,
             extensions: self.extensions,
-            _phantom: PhantomData,
         }
     }
 }
 
-impl<T, B> IntoServiceFactory<AppInit<T, B>, Request> for App<T, B>
+impl<T, B> IntoServiceFactory<AppInit<T, B>, Request> for App<T>
 where
     B: MessageBody,
     T: ServiceFactory<