ex(21): macros

.rustlings-state.txt

···
 DON'T EDIT THIS FILE!
 
-macros1
+clippy1
 
 intro1
 intro2
···
 cow1
 threads1
 threads2
-threads3
+threads3
+macros1
+macros2
+macros3
+macros4

exercises/21_macros/macros1.rs

···
 
 fn main() {
     // TODO: Fix the macro call.
-    my_macro();
+    my_macro!();
 }

exercises/21_macros/macros2.rs

···
-fn main() {
-    my_macro!();
-}
-
 // TODO: Fix the compiler error by moving the whole definition of this macro.
 macro_rules! my_macro {
     () => {
         println!("Check out my macro!");
     };
 }
+
+fn main() {
+    my_macro!();
+}

exercises/21_macros/macros3.rs

···
 // TODO: Fix the compiler error without taking the macro definition out of this
 // module.
+#[macro_use]
 mod macros {
     macro_rules! my_macro {
         () => {

exercises/21_macros/macros4.rs

···
 macro_rules! my_macro {
     () => {
         println!("Check out my macro!");
-    }
+    };
     ($val:expr) => {
         println!("Look at this other macro: {}", $val);
-    }
+    };
 }
 
 fn main() {

solutions/21_macros/macros1.rs

···
+macro_rules! my_macro {
+    () => {
+        println!("Check out my macro!");
+    };
+}
+
 fn main() {
-    // DON'T EDIT THIS SOLUTION FILE!
-    // It will be automatically filled after you finish the exercise.
+    my_macro!();
+    //      ^
 }

solutions/21_macros/macros2.rs

···
+// Moved the macro definition to be before its call.
+macro_rules! my_macro {
+    () => {
+        println!("Check out my macro!");
+    };
+}
+
 fn main() {
-    // DON'T EDIT THIS SOLUTION FILE!
-    // It will be automatically filled after you finish the exercise.
+    my_macro!();
 }

solutions/21_macros/macros3.rs

···
+// Added the attribute `macro_use` attribute.
+#[macro_use]
+mod macros {
+    macro_rules! my_macro {
+        () => {
+            println!("Check out my macro!");
+        };
+    }
+}
+
 fn main() {
-    // DON'T EDIT THIS SOLUTION FILE!
-    // It will be automatically filled after you finish the exercise.
+    my_macro!();
 }

solutions/21_macros/macros4.rs

···
+// 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() {
-    // DON'T EDIT THIS SOLUTION FILE!
-    // It will be automatically filled after you finish the exercise.
+    my_macro!();
+    my_macro!(7777);
 }