solution to exercise 04_05

exercises/04_traits/00_intro/src/lib.rs

@@ -1,6 +1,6 @@
 fn intro() -> &'static str {
     // TODO: fix me 👇
-    "I'm ready to __!"
+    "I'm ready to learn about traits!"
 }
 
 #[cfg(test)]

exercises/04_traits/01_trait/src/lib.rs

@@ -3,6 +3,22 @@
 //
 // Then implement the trait for `u32` and `i32`.
 
+pub trait IsEven {
+    fn is_even(self) -> bool;
+}
+
+impl IsEven for u32 {
+    fn is_even(self) -> bool {
+        self % 2 == 0
+    }
+}
+
+impl IsEven for i32 {
+    fn is_even(self) -> bool {
+        self % 2 == 0
+    }
+}
+
 #[cfg(test)]
 mod tests {
     use super::*;

exercises/04_traits/02_orphan_rule/src/lib.rs

@@ -3,9 +3,3 @@
 //  a foreign type (`u32`, from `std`).
 //  Look at the compiler error to get familiar with what it looks like.
 //  Then delete the code below and move on to the next exercise.
-
-impl PartialEq for u32 {
-    fn eq(&self, _other: &Self) -> bool {
-        todo!()
-    }
-}

exercises/04_traits/03_operator_overloading/src/lib.rs

@@ -8,7 +8,13 @@ struct Ticket {
 
 // TODO: Implement the `PartialEq` trait for `Ticket`.
 
-impl PartialEq for Ticket {}
+impl PartialEq for Ticket {
+    fn eq(&self, other: &Self) -> bool {
+        self.title == other.title
+            && self.description == other.description
+            && self.status == other.status
+    }
+}
 
 #[cfg(test)]
 mod tests {

exercises/04_traits/04_derive/src/lib.rs

@@ -8,7 +8,7 @@
 // print both sides of the comparison to the terminal.
 // If the compared type doesn't implement `Debug`, it doesn't know how to represent them!
 
-#[derive(PartialEq)]
+#[derive(Debug, PartialEq)]
 struct Ticket {
     title: String,
     description: String,

exercises/04_traits/05_trait_bounds/src/lib.rs

@@ -6,7 +6,10 @@
 // collections (e.g. BTreeMap).
 
 /// Return the minimum of two values.
-pub fn min<T>(left: T, right: T) -> T {
+pub fn min<T>(left: T, right: T) -> T
+where
+    T: Ord,
+{
     if left <= right {
         left
     } else {