1 files changed, 38 insertions, 1 deletions
diff --git a/solutions/12_options/options1.rs b/solutions/12_options/options1.rs
index 4e18198..1ffbb04 100644
--- a/solutions/12_options/options1.rs
+++ b/solutions/12_options/options1.rs
@@ -1 +1,38 @@
-// Solutions will be available before the stable release. Thank you for testing the beta version 🥰
+// This function returns how much icecream there is left in the fridge.
+// If it's before 22:00 (24-hour system), then 5 scoops are left. At 22:00,
+// someone eats it all, so no icecream is left (value 0). Return `None` if
+// `hour_of_day` is higher than 23.
+fn maybe_icecream(hour_of_day: u16) -> Option<u16> {
+    match hour_of_day {
+        0..22 => Some(5),
+        22..24 => Some(0),
+        _ => None,
+    }
+}
+
+fn main() {
+    // You can optionally experiment here.
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn raw_value() {
+        // Using `unwrap` is fine in a test.
+        let icecreams = maybe_icecream(12).unwrap();
+        assert_eq!(icecreams, 5);
+    }
+
+    #[test]
+    fn check_icecream() {
+        assert_eq!(maybe_icecream(0), Some(5));
+        assert_eq!(maybe_icecream(9), Some(5));
+        assert_eq!(maybe_icecream(18), Some(5));
+        assert_eq!(maybe_icecream(22), Some(0));
+        assert_eq!(maybe_icecream(23), Some(0));
+        assert_eq!(maybe_icecream(24), None);
+        assert_eq!(maybe_icecream(25), None);
+    }
+}