feat: Make Layered constructor associated function

Author: tottoto

examples/src/grpc-web/server.rs

@@ -33,7 +33,7 @@ async fn main() -> Result<(), Box<dyn std::error::Error>> {
     let addr = "127.0.0.1:3000".parse().unwrap();
 
     let greeter = MyGreeter::default();
-    let greeter = tonic::service::layered_service(
+    let greeter = tonic::service::Layered::new(
         tonic_web::GrpcWebLayer::new().layer(GreeterServer::new(greeter)),
         tower_http::cors::CorsLayer::default(),
     );

tonic/src/service/layered.rs

@@ -10,27 +10,31 @@ use crate::server::NamedService;
 
 /// A layered service to propagate [`NamedService`] implementation.
 #[derive(Debug, Clone)]
-pub struct Layered<S, T> {
+pub struct Layered<S, T, L> {
     inner: S,
-    _ty: PhantomData<T>,
+    _ty_s: PhantomData<T>,
+    _ty_l: PhantomData<L>,
 }
 
-/// Create a new service from the service and the layer.
-pub fn layered_service<S, L>(service: S, layer: L) -> Layered<L::Service, S>
+impl<S, L> Layered<L::Service, S, L>
 where
     L: Layer<S>,
 {
-    Layered {
-        inner: layer.layer(service),
-        _ty: PhantomData,
+    /// Create a new service from the service and the layer.
+    pub fn new(service: S, layer: L) -> Layered<L::Service, S, L> {
+        Layered {
+            inner: layer.layer(service),
+            _ty_s: PhantomData,
+            _ty_l: PhantomData,
+        }
     }
 }
 
-impl<S, T: NamedService> NamedService for Layered<S, T> {
+impl<S, T: NamedService, L> NamedService for Layered<S, T, L> {
     const NAME: &'static str = T::NAME;
 }
 
-impl<Req, S, T> Service<Req> for Layered<S, T>
+impl<Req, S, T, L> Service<Req> for Layered<S, T, L>
 where
     S: Service<Req>,
 {

tonic/src/service/mod.rs

@@ -7,7 +7,7 @@ pub(crate) mod router;
 
 #[doc(inline)]
 pub use self::interceptor::{interceptor, Interceptor};
-pub use self::layered::{layered_service, Layered};
+pub use self::layered::Layered;
 #[doc(inline)]
 #[cfg(feature = "router")]
 pub use self::router::{Routes, RoutesBuilder};