start 04 traits, completed upto 10

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`.
 
+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

@@ -4,8 +4,8 @@
 //  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!()
-    }
-}
+// 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.description == other.description
+            && self.status == other.status
+            && self.title == other.title
+    }
+}
 
 #[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(PartialEq, Debug)]
 struct Ticket {
     title: String,
     description: String,

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

@@ -5,8 +5,13 @@
 // different _semantics_. We'll cover those differences later in the course when we talk about ordered
 // collections (e.g. BTreeMap).
 
+use std::cmp::PartialOrd;
+use std::fmt::Debug;
 /// 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: Debug + Clone + PartialOrd,
+{
     if left <= right {
         left
     } else {

exercises/04_traits/06_str_slice/src/lib.rs

@@ -31,16 +31,16 @@ impl Ticket {
         }
     }
 
-    pub fn title(&self) -> &String {
-        &self.title
+    pub fn title(&self) -> &str {
+        &self.title.as_str()
     }
 
-    pub fn description(&self) -> &String {
-        &self.description
+    pub fn description(&self) -> &str {
+        &self.description.as_str()
     }
 
-    pub fn status(&self) -> &String {
-        &self.status
+    pub fn status(&self) -> &str {
+        &self.status.as_str()
     }
 }
 

exercises/04_traits/07_deref/src/lib.rs

@@ -12,11 +12,11 @@ pub struct Ticket {
 
 impl Ticket {
     pub fn title(&self) -> &str {
-        todo!()
+        self.title.trim()
     }
 
     pub fn description(&self) -> &str {
-        todo!()
+        self.description.trim()
     }
 }
 

exercises/04_traits/08_sized/src/lib.rs

@@ -3,5 +3,5 @@ pub fn example() {
     // via `std::mem::size_of` will result in a compile-time error.
     //
     // TODO: Comment out the following line and move on to the next exercise.
-    std::mem::size_of::<str>();
+    std::mem::size_of::<&str>();
 }

exercises/04_traits/09_from/src/lib.rs

@@ -4,6 +4,12 @@ pub struct WrappingU32 {
     value: u32,
 }
 
+impl From<u32> for WrappingU32 {
+    fn from(value: u32) -> Self {
+        WrappingU32 { value }
+    }
+}
+
 fn example() {
     let wrapping: WrappingU32 = 42.into();
     let wrapping = WrappingU32::from(42);

exercises/04_traits/10_assoc_vs_generic/src/lib.rs

@@ -13,6 +13,28 @@
 // You don't have to though: it's perfectly okay to write three separate
 // implementations manually. Venture further only if you're curious.
 
+pub trait Power<T> {
+    fn power(&self, power: T) -> Self;
+}
+
+impl Power<u16> for u32 {
+    fn power(&self, power: u16) -> Self {
+        self.pow(power as u32)
+    }
+}
+
+impl Power<u32> for u32 {
+    fn power(&self, power: u32) -> Self {
+        self.pow(power)
+    }
+}
+
+impl Power<&u32> for u32 {
+    fn power(&self, power: &u32) -> Self {
+        self.pow(power.clone())
+    }
+}
+
 #[cfg(test)]
 mod tests {
     use super::Power;