make macro implement trait

axum-extra/src/routing/mod.rs

@@ -3,8 +3,9 @@
 use axum::{body::Body, Router};
 
 mod resource;
+mod typed_path;
 
-pub use self::resource::Resource;
+pub use self::{resource::Resource, typed_path::TypedPath};
 
 /// Extension trait that adds additional methods to [`Router`].
 pub trait RouterExt<B>: sealed::Sealed {

axum-extra/src/routing/typed_path.rs

@@ -0,0 +1,10 @@
+use std::borrow::Cow;
+
+/// TODO
+pub trait TypedPath {
+    /// TODO
+    const PATH: &'static str;
+
+    /// TODO
+    fn path(&self) -> Cow<'static, str>;
+}