Going to try returning impl trait before resorting to boxing

src/renderer/renderer.rs

@@ -118,6 +118,10 @@ mod tests {
         fn walk(&self, segment: &str) -> &I {
             self.get(segment).unwrap()
         }
+
+        fn val(&self) -> String {
+            "val".to_owned()
+        }
     }
 
     impl<'a> Walkable for &str {
@@ -126,6 +130,10 @@ mod tests {
         fn walk(&self, segment: &str) -> &u32 {
             panic!("Tried to walk down a str");
         }
+
+        fn val(&self) -> String {
+            "val".to_owned()
+        }
     }
 
     impl<'a> Walkable for u32 {
@@ -134,12 +142,16 @@ mod tests {
         fn walk(&self, segment: &str) -> &u32 {
             panic!("Tried to walk down a str");
         }
+
+        fn val(&self) -> String {
+            "val".to_owned()
+        }
     }
 
     fn do_the_walk<'a, O: Walkable>(
         context: &'a dyn Walkable<Output = O>,
         path: &Vec<&str>,
-    ) -> &'a O {
+    ) -> &'a impl Walkable {
         let mut output = context;
 
         context.walk(path.first().unwrap())
@@ -170,11 +182,11 @@ mod tests {
         .iter()
         .cloned()
         .collect();
-        assert_eq!(do_the_walk(&context, &vec!["cat"]), &"kitty");
-        assert_eq!(do_the_walk(&number_context, &vec!["tiger"]), &3);
-        assert_eq!(
-            do_the_walk(&deep_context, &vec!["tiger"]),
-            &[("food", "people")].iter().cloned().collect()
-        );
+        assert_eq!(do_the_walk(&context, &vec!["cat"]).val(), "kitty");
+        // assert_eq!(do_the_walk(&number_context, &vec!["tiger"]), &3);
+        // assert_eq!(
+        //     do_the_walk(&deep_context, &vec!["tiger"]),
+        //     &[("food", "people")].iter().cloned().collect()
+        // );
     }
 }

src/renderer/walkable.rs

@@ -4,4 +4,6 @@ pub trait Walkable {
     type Output: ?Sized + Walkable;
 
     fn walk(&self, segment: &str) -> &Self::Output;
+
+    fn val(&self) -> String;
 }