Require a main function in all exercises

2 files changed, 8 insertions, 0 deletions

diff --git a/exercises/12_options/options1.rs b/exercises/12_options/options1.rs
index ba4b1cd..aecb123 100644
--- a/exercises/12_options/options1.rs
+++ b/exercises/12_options/options1.rs
@@ -14,6 +14,10 @@ fn maybe_icecream(time_of_day: u16) -> Option<u16> {
     ???
 }
 
+fn main() {
+    // You can optionally experiment here.
+}
+
 #[cfg(test)]
 mod tests {
     use super::*;
diff --git a/exercises/12_options/options2.rs b/exercises/12_options/options2.rs
index 73f707e..d183d1d 100644
--- a/exercises/12_options/options2.rs
+++ b/exercises/12_options/options2.rs
@@ -3,6 +3,10 @@
 // Execute `rustlings hint options2` or use the `hint` watch subcommand for a
 // hint.
 
+fn main() {
+    // You can optionally experiment here.
+}
+
 #[cfg(test)]
 mod tests {
     #[test]