macros4 solution

exercises/21_macros/macros4.rs

@@ -1,3 +1,4 @@
+// TODO: Fix the compiler error by adding one or two characters.
 #[rustfmt::skip]
 macro_rules! my_macro {
     () => {

solutions/21_macros/macros4.rs

@@ -1 +1,15 @@
-// Solutions will be available before the stable release. Thank you for testing the beta version 🥰
+// Added semicolons to separate the macro arms.
+#[rustfmt::skip]
+macro_rules! my_macro {
+    () => {
+        println!("Check out my macro!");
+    };
+    ($val:expr) => {
+        println!("Look at this other macro: {}", $val);
+    };
+}
+
+fn main() {
+    my_macro!();
+    my_macro!(7777);
+}