1 files changed, 38 insertions, 0 deletions
diff --git a/rustlings/exercises/13_error_handling/errors4.rs b/rustlings/exercises/13_error_handling/errors4.rs
new file mode 100644
index 0000000..144fce7
--- /dev/null
+++ b/rustlings/exercises/13_error_handling/errors4.rs
@@ -0,0 +1,38 @@
+#[derive(PartialEq, Debug)]
+enum CreationError {
+    Negative,
+    Zero,
+}
+
+#[derive(PartialEq, Debug)]
+struct PositiveNonzeroInteger(u64);
+
+impl PositiveNonzeroInteger {
+    fn new(value: i64) -> Result<Self, CreationError> {
+        // TODO: This function shouldn't always return an `Ok`.
+        // Read the tests below to clarify what should be returned.
+        Ok(Self(value as u64))
+    }
+}
+
+fn main() {
+    // You can optionally experiment here.
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_creation() {
+        assert_eq!(
+            PositiveNonzeroInteger::new(10),
+            Ok(PositiveNonzeroInteger(10)),
+        );
+        assert_eq!(
+            PositiveNonzeroInteger::new(-10),
+            Err(CreationError::Negative),
+        );
+        assert_eq!(PositiveNonzeroInteger::new(0), Err(CreationError::Zero));
+    }
+}