Day 18

src/util/maps.rs

@@ -154,9 +154,20 @@ where
     }
 
     pub fn map<U: Copy, F: Fn(&T) -> U>(&self, f: F) -> World<U> {
-        let v = self.map.iter().map(|row| row.iter().map(|e| f(e)).collect()).collect();
+        let v = self
+            .map
+            .iter()
+            .map(|row| row.iter().map(|e| f(e)).collect())
+            .collect();
         World::<U>::from_2d_vec(v)
     }
+
+    pub fn adjacent_locations(&self, x: usize, y: usize) -> Vec<(usize, usize)> {
+        Direction::all_variants()
+            .into_iter()
+            .filter_map(|d| self.travel(x, y, d))
+            .collect()
+    }
 }
 
 impl<T> Display for World<T>