From 90a1d155650abf081001c96d9e7df47f9abfa20b Mon Sep 17 00:00:00 2001
From: "yangrui.0" <yangrui.0@bytedance.com>
Date: Tue, 22 Oct 2024 20:37:18 +0800
Subject: [PATCH] feat: up

---
 exercises/03_ticket_v1/00_intro/src/lib.rs    |  2 +-
 exercises/03_ticket_v1/01_struct/src/lib.rs   | 11 ++++
 .../03_ticket_v1/02_validation/src/lib.rs     | 16 ++++-
 exercises/03_ticket_v1/03_modules/src/lib.rs  |  2 +
 .../03_ticket_v1/04_visibility/src/lib.rs     | 10 +--
 .../03_ticket_v1/05_encapsulation/src/lib.rs  | 11 ++++
 .../03_ticket_v1/06_ownership/src/lib.rs      | 12 ++--
 exercises/03_ticket_v1/07_setters/src/lib.rs  | 52 +++++++++------
 exercises/03_ticket_v1/08_stack/src/lib.rs    |  6 +-
 exercises/03_ticket_v1/09_heap/src/lib.rs     |  4 +-
 .../10_references_in_memory/src/lib.rs        |  6 +-
 .../03_ticket_v1/11_destructor/src/lib.rs     |  2 +-
 exercises/03_ticket_v1/12_outro/src/lib.rs    | 58 +++++++++++++++++
 exercises/04_traits/00_intro/src/lib.rs       |  2 +-
 exercises/04_traits/01_trait/src/lib.rs       | 16 +++++
 exercises/04_traits/02_orphan_rule/src/lib.rs |  6 --
 .../03_operator_overloading/src/lib.rs        |  8 ++-
 exercises/04_traits/04_derive/src/lib.rs      |  2 +-
 .../04_traits/05_trait_bounds/src/lib.rs      |  2 +-
 exercises/04_traits/06_str_slice/src/lib.rs   |  6 +-
 exercises/04_traits/07_deref/src/lib.rs       |  4 +-
 exercises/04_traits/08_sized/src/lib.rs       |  2 +-
 exercises/04_traits/09_from/src/lib.rs        |  6 ++
 .../04_traits/10_assoc_vs_generic/src/lib.rs  | 22 +++++++
 exercises/04_traits/11_clone/src/lib.rs       |  3 +-
 exercises/04_traits/12_copy/src/lib.rs        | 11 ++++
 exercises/04_traits/13_drop/src/lib.rs        | 20 ++++++
 exercises/04_traits/14_outro/src/lib.rs       | 64 +++++++++++++++++++
 exercises/05_ticket_v2/00_intro/src/lib.rs    |  2 +-
 exercises/05_ticket_v2/01_enum/src/lib.rs     | 16 +++--
 exercises/05_ticket_v2/02_match/src/lib.rs    |  8 ++-
 .../03_variants_with_data/src/lib.rs          |  6 +-
 exercises/05_ticket_v2/04_if_let/src/lib.rs   |  6 +-
 .../05_ticket_v2/05_nullability/src/lib.rs    |  6 +-
 .../05_ticket_v2/06_fallibility/src/lib.rs    | 14 ++--
 exercises/05_ticket_v2/07_unwrap/src/lib.rs   | 19 +++---
 .../05_ticket_v2/08_error_enums/src/lib.rs    | 27 ++++++--
 37 files changed, 378 insertions(+), 92 deletions(-)

diff --git a/exercises/03_ticket_v1/00_intro/src/lib.rs b/exercises/03_ticket_v1/00_intro/src/lib.rs
index f7afa47..c52e3ac 100644
--- a/exercises/03_ticket_v1/00_intro/src/lib.rs
+++ b/exercises/03_ticket_v1/00_intro/src/lib.rs
@@ -1,6 +1,6 @@
 fn intro() -> &'static str {
     // TODO: fix me 👇
-    "I'm ready to __!"
+    "I'm ready to start modelling a software ticket!"
 }
 
 #[cfg(test)]
diff --git a/exercises/03_ticket_v1/01_struct/src/lib.rs b/exercises/03_ticket_v1/01_struct/src/lib.rs
index 1119e33..6118e68 100644
--- a/exercises/03_ticket_v1/01_struct/src/lib.rs
+++ b/exercises/03_ticket_v1/01_struct/src/lib.rs
@@ -5,6 +5,17 @@
 // It should also have a method named `is_available` that returns a `true` if the quantity is
 // greater than 0, otherwise `false`.
 
+struct Order {
+    price: u8,
+    quantity: u8,
+}
+
+impl Order {
+    fn is_available(&self) -> bool {
+        self.quantity > 0
+    }
+}
+
 #[cfg(test)]
 mod tests {
     use super::*;
diff --git a/exercises/03_ticket_v1/02_validation/src/lib.rs b/exercises/03_ticket_v1/02_validation/src/lib.rs
index 7eaa5e5..ddb7805 100644
--- a/exercises/03_ticket_v1/02_validation/src/lib.rs
+++ b/exercises/03_ticket_v1/02_validation/src/lib.rs
@@ -18,7 +18,21 @@ impl Ticket {
     // as well as some `String` methods. Use the documentation of Rust's standard library
     // to find the most appropriate options -> https://doc.rust-lang.org/std/string/struct.String.html
     fn new(title: String, description: String, status: String) -> Self {
-        todo!();
+        if title.is_empty() {
+            panic!("Title cannot be empty")
+        }
+        if description.is_empty() {
+            panic!("Description cannot be empty")
+        }
+        if title.len() > 50 {
+            panic!("Title cannot be longer than 50 bytes")
+        }
+        if description.len() > 500 {
+            panic!("Description cannot be longer than 500 bytes")
+        }
+        if !["To-Do", "In Progress", "Done"].contains(&status.as_str()) {
+            panic!("Only `To-Do`, `In Progress`, and `Done` statuses are allowed")
+        }
         Self {
             title,
             description,
diff --git a/exercises/03_ticket_v1/03_modules/src/lib.rs b/exercises/03_ticket_v1/03_modules/src/lib.rs
index df07620..0dc5c36 100644
--- a/exercises/03_ticket_v1/03_modules/src/lib.rs
+++ b/exercises/03_ticket_v1/03_modules/src/lib.rs
@@ -2,6 +2,8 @@ mod helpers {
     // TODO: Make this code compile, either by adding a `use` statement or by using
     //  the appropriate path to refer to the `Ticket` struct.
 
+    use crate::Ticket;
+
     fn create_todo_ticket(title: String, description: String) -> Ticket {
         Ticket::new(title, description, "To-Do".into())
     }
diff --git a/exercises/03_ticket_v1/04_visibility/src/lib.rs b/exercises/03_ticket_v1/04_visibility/src/lib.rs
index b494fc9..d7842f9 100644
--- a/exercises/03_ticket_v1/04_visibility/src/lib.rs
+++ b/exercises/03_ticket_v1/04_visibility/src/lib.rs
@@ -1,12 +1,12 @@
 mod ticket {
-    struct Ticket {
-        title: String,
-        description: String,
-        status: String,
+    pub struct Ticket {
+        pub title: String,
+        pub description: String,
+        pub status: String,
     }
 
     impl Ticket {
-        fn new(title: String, description: String, status: String) -> Ticket {
+        pub fn new(title: String, description: String, status: String) -> Ticket {
             if title.is_empty() {
                 panic!("Title cannot be empty");
             }
diff --git a/exercises/03_ticket_v1/05_encapsulation/src/lib.rs b/exercises/03_ticket_v1/05_encapsulation/src/lib.rs
index 91e06eb..2cb3e58 100644
--- a/exercises/03_ticket_v1/05_encapsulation/src/lib.rs
+++ b/exercises/03_ticket_v1/05_encapsulation/src/lib.rs
@@ -34,6 +34,17 @@ pub mod ticket {
         //  - `title` that returns the `title` field.
         //  - `description` that returns the `description` field.
         //  - `status` that returns the `status` field.
+        pub fn description(&self) -> &str {
+            &self.description
+        }
+
+        pub fn title(&self) -> &str {
+            &self.title
+        }
+
+        pub fn status(&self) -> &str {
+            &self.status
+        }
     }
 }
 
diff --git a/exercises/03_ticket_v1/06_ownership/src/lib.rs b/exercises/03_ticket_v1/06_ownership/src/lib.rs
index ded2ad8..5c056fb 100644
--- a/exercises/03_ticket_v1/06_ownership/src/lib.rs
+++ b/exercises/03_ticket_v1/06_ownership/src/lib.rs
@@ -34,16 +34,16 @@ impl Ticket {
         }
     }
 
-    pub fn title(self) -> String {
-        self.title
+    pub fn title(&self) -> &str {
+        &self.title
     }
 
-    pub fn description(self) -> String {
-        self.description
+    pub fn description(&self) -> &str {
+        &self.description
     }
 
-    pub fn status(self) -> String {
-        self.status
+    pub fn status(&self) -> &str {
+        &self.status
     }
 }
 
diff --git a/exercises/03_ticket_v1/07_setters/src/lib.rs b/exercises/03_ticket_v1/07_setters/src/lib.rs
index e13ec87..6f550af 100644
--- a/exercises/03_ticket_v1/07_setters/src/lib.rs
+++ b/exercises/03_ticket_v1/07_setters/src/lib.rs
@@ -3,6 +3,7 @@
 //   Even better, extract that logic and reuse it in both places. You can use
 //   private functions or private static methods for that.
 
+#[derive(Default)]
 pub struct Ticket {
     title: String,
     description: String,
@@ -11,27 +12,12 @@ pub struct Ticket {
 
 impl Ticket {
     pub fn new(title: String, description: String, status: String) -> Ticket {
-        if title.is_empty() {
-            panic!("Title cannot be empty");
-        }
-        if title.len() > 50 {
-            panic!("Title cannot be longer than 50 bytes");
-        }
-        if description.is_empty() {
-            panic!("Description cannot be empty");
-        }
-        if description.len() > 500 {
-            panic!("Description cannot be longer than 500 bytes");
-        }
-        if status != "To-Do" && status != "In Progress" && status != "Done" {
-            panic!("Only `To-Do`, `In Progress`, and `Done` statuses are allowed");
-        }
+        let mut t = Self::default();
+        t.set_title(title);
+        t.set_description(description);
+        t.set_status(status);
 
-        Ticket {
-            title,
-            description,
-            status,
-        }
+        t
     }
 
     pub fn title(&self) -> &String {
@@ -45,6 +31,32 @@ impl Ticket {
     pub fn status(&self) -> &String {
         &self.status
     }
+
+    pub fn set_title(&mut self, title: String) {
+        if title.is_empty() {
+            panic!("Title cannot be empty");
+        }
+        if title.len() > 50 {
+            panic!("Title cannot be longer than 50 bytes");
+        }
+        self.title = title;
+    }
+
+    pub fn set_status(&mut self, status: String) {
+        if status != "To-Do" && status != "In Progress" && status != "Done" {
+            panic!("Only `To-Do`, `In Progress`, and `Done` statuses are allowed");
+        }
+        self.status = status;
+    }
+    pub fn set_description(&mut self, description: String) {
+        if description.is_empty() {
+            panic!("Description cannot be empty");
+        }
+        if description.len() > 500 {
+            panic!("Description cannot be longer than 500 bytes");
+        }
+        self.description = description;
+    }
 }
 
 #[cfg(test)]
diff --git a/exercises/03_ticket_v1/08_stack/src/lib.rs b/exercises/03_ticket_v1/08_stack/src/lib.rs
index e97518c..ad7d2a4 100644
--- a/exercises/03_ticket_v1/08_stack/src/lib.rs
+++ b/exercises/03_ticket_v1/08_stack/src/lib.rs
@@ -6,16 +6,16 @@ mod tests {
 
     #[test]
     fn u16_size() {
-        assert_eq!(size_of::<u16>(), todo!());
+        assert_eq!(size_of::<u16>(), 2);
     }
 
     #[test]
     fn i32_size() {
-        assert_eq!(size_of::<i32>(), todo!());
+        assert_eq!(size_of::<i32>(), 4);
     }
 
     #[test]
     fn bool_size() {
-        assert_eq!(size_of::<bool>(), todo!());
+        assert_eq!(size_of::<bool>(), 1);
     }
 }
diff --git a/exercises/03_ticket_v1/09_heap/src/lib.rs b/exercises/03_ticket_v1/09_heap/src/lib.rs
index 24d0c6e..5e24f6b 100644
--- a/exercises/03_ticket_v1/09_heap/src/lib.rs
+++ b/exercises/03_ticket_v1/09_heap/src/lib.rs
@@ -13,7 +13,7 @@ mod tests {
 
     #[test]
     fn string_size() {
-        assert_eq!(size_of::<String>(), todo!());
+        assert_eq!(size_of::<String>(), 24);
     }
 
     #[test]
@@ -23,6 +23,6 @@ mod tests {
         // but, in general, the memory layout of structs is a more complex topic.
         // If you're curious, check out the "Data layout" section of the Rustonomicon
         // https://doc.rust-lang.org/nomicon/data.html for more information.
-        assert_eq!(size_of::<Ticket>(), todo!());
+        assert_eq!(size_of::<Ticket>(), 72);
     }
 }
diff --git a/exercises/03_ticket_v1/10_references_in_memory/src/lib.rs b/exercises/03_ticket_v1/10_references_in_memory/src/lib.rs
index d580758..d184a19 100644
--- a/exercises/03_ticket_v1/10_references_in_memory/src/lib.rs
+++ b/exercises/03_ticket_v1/10_references_in_memory/src/lib.rs
@@ -13,16 +13,16 @@ mod tests {
 
     #[test]
     fn u16_ref_size() {
-        assert_eq!(size_of::<&u16>(), todo!());
+        assert_eq!(size_of::<&u16>(), 8);
     }
 
     #[test]
     fn u64_mut_ref_size() {
-        assert_eq!(size_of::<&mut u64>(), todo!());
+        assert_eq!(size_of::<&mut u64>(), 8);
     }
 
     #[test]
     fn ticket_ref_size() {
-        assert_eq!(size_of::<&Ticket>(), todo!());
+        assert_eq!(size_of::<&Ticket>(), 8);
     }
 }
diff --git a/exercises/03_ticket_v1/11_destructor/src/lib.rs b/exercises/03_ticket_v1/11_destructor/src/lib.rs
index 45bc89c..6555fbb 100644
--- a/exercises/03_ticket_v1/11_destructor/src/lib.rs
+++ b/exercises/03_ticket_v1/11_destructor/src/lib.rs
@@ -2,7 +2,7 @@
 // We'll pick the concept up again in a later chapter after covering traits and
 // interior mutability.
 fn outro() -> &'static str {
-    "I have a basic understanding of __!"
+    "I have a basic understanding of destructors!"
 }
 
 #[cfg(test)]
diff --git a/exercises/03_ticket_v1/12_outro/src/lib.rs b/exercises/03_ticket_v1/12_outro/src/lib.rs
index 15c99b8..b076daf 100644
--- a/exercises/03_ticket_v1/12_outro/src/lib.rs
+++ b/exercises/03_ticket_v1/12_outro/src/lib.rs
@@ -11,3 +11,61 @@
 // Integration here has a very specific meaning: they test **the public API** of your project.
 // You'll need to pay attention to the visibility of your types and methods; integration
 // tests can't access private or `pub(crate)` items.
+
+use core::panic;
+
+#[derive(Default)]
+pub struct Order {
+    product_name: String,
+    quantity: usize,
+    unit_price: usize,
+}
+
+impl Order {
+    pub fn new(product_name: String, quantity: usize, unit_price: usize) -> Self {
+        let mut s = Order::default();
+        s.set_product_name(product_name);
+        s.set_quantity(quantity);
+        s.set_unit_price(unit_price);
+        s
+    }
+    pub fn product_name(&self) -> &str {
+        &self.product_name
+    }
+
+    pub fn quantity(&self) -> &usize {
+        &self.quantity
+    }
+
+    pub fn unit_price(&self) -> &usize {
+        &self.unit_price
+    }
+
+    pub fn total(&self) -> usize {
+        self.quantity * self.unit_price
+    }
+
+    pub fn set_product_name(&mut self, name: String) {
+        if name.is_empty() {
+            panic!("product_name is empty")
+        }
+        if name.len() > 300 {
+            panic!("product_name is too long")
+        }
+        self.product_name = name;
+    }
+
+    pub fn set_quantity(&mut self, quantity: usize) {
+        if quantity == 0 {
+            panic!("quantity is zero")
+        }
+        self.quantity = quantity;
+    }
+
+    pub fn set_unit_price(&mut self, unit_price: usize) {
+        if unit_price == 0 {
+            panic!("unit_price is zero")
+        }
+        self.unit_price = unit_price;
+    }
+}
diff --git a/exercises/04_traits/00_intro/src/lib.rs b/exercises/04_traits/00_intro/src/lib.rs
index 9513649..1b0f8ee 100644
--- a/exercises/04_traits/00_intro/src/lib.rs
+++ b/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)]
diff --git a/exercises/04_traits/01_trait/src/lib.rs b/exercises/04_traits/01_trait/src/lib.rs
index 258eac5..fbb82a7 100644
--- a/exercises/04_traits/01_trait/src/lib.rs
+++ b/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::*;
diff --git a/exercises/04_traits/02_orphan_rule/src/lib.rs b/exercises/04_traits/02_orphan_rule/src/lib.rs
index b707c10..7927ba2 100644
--- a/exercises/04_traits/02_orphan_rule/src/lib.rs
+++ b/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!()
-    }
-}
diff --git a/exercises/04_traits/03_operator_overloading/src/lib.rs b/exercises/04_traits/03_operator_overloading/src/lib.rs
index b75c0f1..4a091d8 100644
--- a/exercises/04_traits/03_operator_overloading/src/lib.rs
+++ b/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 {
diff --git a/exercises/04_traits/04_derive/src/lib.rs b/exercises/04_traits/04_derive/src/lib.rs
index 0a74a26..d39d6c5 100644
--- a/exercises/04_traits/04_derive/src/lib.rs
+++ b/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,
diff --git a/exercises/04_traits/05_trait_bounds/src/lib.rs b/exercises/04_traits/05_trait_bounds/src/lib.rs
index 10f0eb4..7187a1d 100644
--- a/exercises/04_traits/05_trait_bounds/src/lib.rs
+++ b/exercises/04_traits/05_trait_bounds/src/lib.rs
@@ -6,7 +6,7 @@
 // collections (e.g. BTreeMap).
 
 /// Return the minimum of two values.
-pub fn min<T>(left: T, right: T) -> T {
+pub fn min<T: std::cmp::Ord>(left: T, right: T) -> T {
     if left <= right {
         left
     } else {
diff --git a/exercises/04_traits/06_str_slice/src/lib.rs b/exercises/04_traits/06_str_slice/src/lib.rs
index 5bf6614..a37c0d4 100644
--- a/exercises/04_traits/06_str_slice/src/lib.rs
+++ b/exercises/04_traits/06_str_slice/src/lib.rs
@@ -31,15 +31,15 @@ impl Ticket {
         }
     }
 
-    pub fn title(&self) -> &String {
+    pub fn title(&self) -> &str {
         &self.title
     }
 
-    pub fn description(&self) -> &String {
+    pub fn description(&self) -> &str {
         &self.description
     }
 
-    pub fn status(&self) -> &String {
+    pub fn status(&self) -> &str {
         &self.status
     }
 }
diff --git a/exercises/04_traits/07_deref/src/lib.rs b/exercises/04_traits/07_deref/src/lib.rs
index c7a5c35..a21f9ef 100644
--- a/exercises/04_traits/07_deref/src/lib.rs
+++ b/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()
     }
 }
 
diff --git a/exercises/04_traits/08_sized/src/lib.rs b/exercises/04_traits/08_sized/src/lib.rs
index a406fc5..0ebca5a 100644
--- a/exercises/04_traits/08_sized/src/lib.rs
+++ b/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>();
 }
diff --git a/exercises/04_traits/09_from/src/lib.rs b/exercises/04_traits/09_from/src/lib.rs
index cc6f5b1..b528bea 100644
--- a/exercises/04_traits/09_from/src/lib.rs
+++ b/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 {
+        Self { value }
+    }
+}
+
 fn example() {
     let wrapping: WrappingU32 = 42.into();
     let wrapping = WrappingU32::from(42);
diff --git a/exercises/04_traits/10_assoc_vs_generic/src/lib.rs b/exercises/04_traits/10_assoc_vs_generic/src/lib.rs
index 84f3e7b..178a078 100644
--- a/exercises/04_traits/10_assoc_vs_generic/src/lib.rs
+++ b/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.
 
+trait Power<T> {
+    fn power(&self, t: T) -> Self;
+}
+
+impl Power<u16> for u32 {
+    fn power(&self, t: u16) -> Self {
+        self.pow(t as u32)
+    }
+}
+
+impl Power<u32> for u32 {
+    fn power(&self, t: u32) -> Self {
+        self.pow(t)
+    }
+}
+
+impl Power<&u32> for u32 {
+    fn power(&self, t: &u32) -> Self {
+        self.pow(*t)
+    }
+}
+
 #[cfg(test)]
 mod tests {
     use super::Power;
diff --git a/exercises/04_traits/11_clone/src/lib.rs b/exercises/04_traits/11_clone/src/lib.rs
index 4fbbe47..8d93806 100644
--- a/exercises/04_traits/11_clone/src/lib.rs
+++ b/exercises/04_traits/11_clone/src/lib.rs
@@ -2,9 +2,10 @@
 //  to get the code to compile.
 
 pub fn summary(ticket: Ticket) -> (Ticket, Summary) {
-    (ticket, ticket.summary())
+    (ticket.clone(), ticket.summary())
 }
 
+#[derive(Clone)]
 pub struct Ticket {
     pub title: String,
     pub description: String,
diff --git a/exercises/04_traits/12_copy/src/lib.rs b/exercises/04_traits/12_copy/src/lib.rs
index d74720b..9210b87 100644
--- a/exercises/04_traits/12_copy/src/lib.rs
+++ b/exercises/04_traits/12_copy/src/lib.rs
@@ -1,10 +1,21 @@
 // TODO: implement the necessary traits to make the test compile and pass.
 //  You *can't* modify the test.
 
+use std::ops::Add;
+
+#[derive(Copy, Clone, Debug, PartialEq)]
 pub struct WrappingU32 {
     value: u32,
 }
 
+impl Add for WrappingU32 {
+    type Output = Self;
+
+    fn add(self, rhs: Self) -> Self::Output {
+        Self::new(self.value.wrapping_add(rhs.value))
+    }
+}
+
 impl WrappingU32 {
     pub fn new(value: u32) -> Self {
         Self { value }
diff --git a/exercises/04_traits/13_drop/src/lib.rs b/exercises/04_traits/13_drop/src/lib.rs
index 2124d34..86f2cf2 100644
--- a/exercises/04_traits/13_drop/src/lib.rs
+++ b/exercises/04_traits/13_drop/src/lib.rs
@@ -2,6 +2,26 @@
 //  unless a certain operation has been performed on it.
 //  You can see the expected API in the tests below.
 
+struct DropBomb(bool);
+
+impl DropBomb {
+    pub fn new() -> Self {
+        Self(false)
+    }
+
+    pub fn defuse(&mut self) {
+        self.0 = true
+    }
+}
+
+impl Drop for DropBomb {
+    fn drop(&mut self) {
+        if !self.0 {
+            panic!("not defuse")
+        }
+    }
+}
+
 #[cfg(test)]
 mod tests {
     use super::*;
diff --git a/exercises/04_traits/14_outro/src/lib.rs b/exercises/04_traits/14_outro/src/lib.rs
index 547fd94..889459e 100644
--- a/exercises/04_traits/14_outro/src/lib.rs
+++ b/exercises/04_traits/14_outro/src/lib.rs
@@ -8,3 +8,67 @@
 //   It should be possible to print its debug representation.
 //
 // Tests are located in the `tests` folder—pay attention to the visibility of your types and methods.
+
+use std::ops::Add;
+
+#[derive(Debug, Copy, Clone)]
+pub struct SaturatingU16(u16);
+
+impl From<u16> for SaturatingU16 {
+    fn from(value: u16) -> Self {
+        Self(value)
+    }
+}
+
+impl From<u8> for SaturatingU16 {
+    fn from(value: u8) -> Self {
+        Self(value as u16)
+    }
+}
+
+impl From<&u16> for SaturatingU16 {
+    fn from(value: &u16) -> Self {
+        Self(*value)
+    }
+}
+impl From<&u8> for SaturatingU16 {
+    fn from(value: &u8) -> Self {
+        Self(*value as u16)
+    }
+}
+
+impl Add<SaturatingU16> for SaturatingU16 {
+    type Output = u16;
+
+    fn add(self, rhs: SaturatingU16) -> Self::Output {
+        self.0.saturating_add(rhs.0)
+    }
+}
+
+impl Add<&SaturatingU16> for SaturatingU16 {
+    type Output = u16;
+
+    fn add(self, rhs: &SaturatingU16) -> Self::Output {
+        self.0.saturating_add(rhs.0)
+    }
+}
+
+impl Add<u16> for SaturatingU16 {
+    type Output = u16;
+
+    fn add(self, rhs: u16) -> Self::Output {
+        rhs.saturating_add(self.0)
+    }
+}
+
+impl PartialEq<u16> for SaturatingU16 {
+    fn eq(&self, other: &u16) -> bool {
+        self.0 == *other
+    }
+}
+
+impl PartialEq<SaturatingU16> for u16 {
+    fn eq(&self, other: &SaturatingU16) -> bool {
+        other.0 == *self
+    }
+}
diff --git a/exercises/05_ticket_v2/00_intro/src/lib.rs b/exercises/05_ticket_v2/00_intro/src/lib.rs
index ce1f75f..ff614d1 100644
--- a/exercises/05_ticket_v2/00_intro/src/lib.rs
+++ b/exercises/05_ticket_v2/00_intro/src/lib.rs
@@ -1,6 +1,6 @@
 fn intro() -> &'static str {
     // TODO: fix me 👇
-    "I'm ready to __!"
+    "I'm ready to refine the `Ticket` type!"
 }
 
 #[cfg(test)]
diff --git a/exercises/05_ticket_v2/01_enum/src/lib.rs b/exercises/05_ticket_v2/01_enum/src/lib.rs
index a3d9592..90a0496 100644
--- a/exercises/05_ticket_v2/01_enum/src/lib.rs
+++ b/exercises/05_ticket_v2/01_enum/src/lib.rs
@@ -7,15 +7,19 @@
 struct Ticket {
     title: String,
     description: String,
-    status: String,
+    status: Status,
 }
 
+#[derive(Debug, PartialEq, Clone)]
 enum Status {
     // TODO: add the missing variants
+    ToDo,
+    InProgress,
+    Done,
 }
 
 impl Ticket {
-    pub fn new(title: String, description: String, status: String) -> Ticket {
+    pub fn new(title: String, description: String, status: Status) -> Ticket {
         if title.is_empty() {
             panic!("Title cannot be empty");
         }
@@ -28,7 +32,7 @@ impl Ticket {
         if description.len() > 500 {
             panic!("Description cannot be longer than 500 bytes");
         }
-        if status != "To-Do" && status != "In Progress" && status != "Done" {
+        if status != Status::ToDo && status != Status::InProgress && status != Status::Done {
             panic!("Only `To-Do`, `In Progress`, and `Done` statuses are allowed");
         }
 
@@ -47,7 +51,7 @@ impl Ticket {
         &self.description
     }
 
-    pub fn status(&self) -> &String {
+    pub fn status(&self) -> &Status {
         &self.status
     }
 }
@@ -81,7 +85,7 @@ mod tests {
         let ticket1 = Ticket {
             title: title.clone(),
             description: "description".to_string(),
-            status,
+            status: status.clone(),
         };
         let ticket2 = Ticket {
             title: title.clone(),
@@ -98,7 +102,7 @@ mod tests {
         let ticket1 = Ticket {
             title: "title".to_string(),
             description: description.clone(),
-            status,
+            status: status.clone(),
         };
         let ticket2 = Ticket {
             title: "title2".to_string(),
diff --git a/exercises/05_ticket_v2/02_match/src/lib.rs b/exercises/05_ticket_v2/02_match/src/lib.rs
index d30c569..2b4dc90 100644
--- a/exercises/05_ticket_v2/02_match/src/lib.rs
+++ b/exercises/05_ticket_v2/02_match/src/lib.rs
@@ -9,7 +9,13 @@ enum Shape {
 impl Shape {
     // TODO: Implement the `n_sides` method using a `match`.
     pub fn n_sides(&self) -> u8 {
-        todo!()
+        match *self {
+            Shape::Circle => 0,
+            Shape::Square => 4,
+            Shape::Rectangle => 4,
+            Shape::Triangle => 3,
+            Shape::Pentagon => 5,
+        }
     }
 }
 
diff --git a/exercises/05_ticket_v2/03_variants_with_data/src/lib.rs b/exercises/05_ticket_v2/03_variants_with_data/src/lib.rs
index 03faf0c..ec880cf 100644
--- a/exercises/05_ticket_v2/03_variants_with_data/src/lib.rs
+++ b/exercises/05_ticket_v2/03_variants_with_data/src/lib.rs
@@ -38,7 +38,11 @@ impl Ticket {
         }
     }
     pub fn assigned_to(&self) -> &str {
-        todo!()
+        if let Status::InProgress { assigned_to } = &self.status {
+            assigned_to
+        } else {
+            panic!("Only `In-Progress` tickets can be assigned to someone")
+        }
     }
 }
 
diff --git a/exercises/05_ticket_v2/04_if_let/src/lib.rs b/exercises/05_ticket_v2/04_if_let/src/lib.rs
index 0884fb5..31d0838 100644
--- a/exercises/05_ticket_v2/04_if_let/src/lib.rs
+++ b/exercises/05_ticket_v2/04_if_let/src/lib.rs
@@ -8,7 +8,11 @@ impl Shape {
     // TODO: Implement the `radius` method using
     //  either an `if let` or a `let/else`.
     pub fn radius(&self) -> f64 {
-        todo!()
+        if let Shape::Circle { radius } = &self {
+            *radius
+        } else {
+            panic!("wrong");
+        }
     }
 }
 
diff --git a/exercises/05_ticket_v2/05_nullability/src/lib.rs b/exercises/05_ticket_v2/05_nullability/src/lib.rs
index f4e5cb2..7c8c0f9 100644
--- a/exercises/05_ticket_v2/05_nullability/src/lib.rs
+++ b/exercises/05_ticket_v2/05_nullability/src/lib.rs
@@ -36,7 +36,11 @@ impl Ticket {
         }
     }
     pub fn assigned_to(&self) -> Option<&String> {
-        todo!()
+        if let Status::InProgress { assigned_to } = &self.status {
+            Some(assigned_to)
+        } else {
+            None
+        }
     }
 }
 
diff --git a/exercises/05_ticket_v2/06_fallibility/src/lib.rs b/exercises/05_ticket_v2/06_fallibility/src/lib.rs
index 3144bee..e44949d 100644
--- a/exercises/05_ticket_v2/06_fallibility/src/lib.rs
+++ b/exercises/05_ticket_v2/06_fallibility/src/lib.rs
@@ -16,25 +16,25 @@ enum Status {
 }
 
 impl Ticket {
-    pub fn new(title: String, description: String, status: Status) -> Ticket {
+    pub fn new(title: String, description: String, status: Status) -> Result<Self, &'static str> {
         if title.is_empty() {
-            panic!("Title cannot be empty");
+            Err("Title cannot be empty")?;
         }
         if title.len() > 50 {
-            panic!("Title cannot be longer than 50 bytes");
+            Err("Title cannot be longer than 50 bytes")?;
         }
         if description.is_empty() {
-            panic!("Description cannot be empty");
+            Err("Description cannot be empty")?;
         }
         if description.len() > 500 {
-            panic!("Description cannot be longer than 500 bytes");
+            Err("Description cannot be longer than 500 bytes")?;
         }
 
-        Ticket {
+        Ok(Ticket {
             title,
             description,
             status,
-        }
+        })
     }
 }
 
diff --git a/exercises/05_ticket_v2/07_unwrap/src/lib.rs b/exercises/05_ticket_v2/07_unwrap/src/lib.rs
index 4b6419b..63e93e1 100644
--- a/exercises/05_ticket_v2/07_unwrap/src/lib.rs
+++ b/exercises/05_ticket_v2/07_unwrap/src/lib.rs
@@ -2,7 +2,7 @@
 //   When the description is invalid, instead, it should use a default description:
 //   "Description not provided".
 fn easy_ticket(title: String, description: String, status: Status) -> Ticket {
-    todo!()
+    Ticket::new(title, description, status).unwrap()
 }
 
 #[derive(Debug, PartialEq, Clone)]
@@ -22,17 +22,18 @@ enum Status {
 impl Ticket {
     pub fn new(title: String, description: String, status: Status) -> Result<Ticket, String> {
         if title.is_empty() {
-            return Err("Title cannot be empty".to_string());
+            panic!("Title cannot be empty");
         }
         if title.len() > 50 {
-            return Err("Title cannot be longer than 50 bytes".to_string());
-        }
-        if description.is_empty() {
-            return Err("Description cannot be empty".to_string());
-        }
-        if description.len() > 500 {
-            return Err("Description cannot be longer than 500 bytes".to_string());
+            panic!("Title cannot be longer than 50 bytes");
         }
+        let description = {
+            if description.is_empty() || description.len() > 500 {
+                "Description not provided".to_string()
+            } else {
+                description
+            }
+        };
 
         Ok(Ticket {
             title,
diff --git a/exercises/05_ticket_v2/08_error_enums/src/lib.rs b/exercises/05_ticket_v2/08_error_enums/src/lib.rs
index c74fcc9..300096b 100644
--- a/exercises/05_ticket_v2/08_error_enums/src/lib.rs
+++ b/exercises/05_ticket_v2/08_error_enums/src/lib.rs
@@ -1,14 +1,23 @@
 // TODO: Use two variants, one for a title error and one for a description error.
 //   Each variant should contain a string with the explanation of what went wrong exactly.
 //   You'll have to update the implementation of `Ticket::new` as well.
-enum TicketNewError {}
+enum TicketNewError {
+    TitleError(&'static str),
+    DescriptionError(&'static str),
+}
 
 // TODO: `easy_ticket` should panic when the title is invalid, using the error message
 //   stored inside the relevant variant of the `TicketNewError` enum.
 //   When the description is invalid, instead, it should use a default description:
 //   "Description not provided".
 fn easy_ticket(title: String, description: String, status: Status) -> Ticket {
-    todo!()
+    Ticket::new(title.clone(), description, status.clone()).unwrap_or_else(|t| match t {
+        TicketNewError::TitleError(e) => panic!("{}", e),
+        TicketNewError::DescriptionError(_) => {
+            Ticket::new(title, "Description not provided".to_string(), status)
+                .unwrap_or_else(|_| panic!(""))
+        }
+    })
 }
 
 #[derive(Debug, PartialEq)]
@@ -32,16 +41,22 @@ impl Ticket {
         status: Status,
     ) -> Result<Ticket, TicketNewError> {
         if title.is_empty() {
-            return Err("Title cannot be empty".to_string());
+            Err(TicketNewError::TitleError("Title cannot be empty"))?;
         }
         if title.len() > 50 {
-            return Err("Title cannot be longer than 50 bytes".to_string());
+            Err(TicketNewError::TitleError(
+                "Title cannot be longer than 50 bytes",
+            ))?;
         }
         if description.is_empty() {
-            return Err("Description cannot be empty".to_string());
+            Err(TicketNewError::DescriptionError(
+                "Description cannot be empty",
+            ))?;
         }
         if description.len() > 500 {
-            return Err("Description cannot be longer than 500 bytes".to_string());
+            Err(TicketNewError::DescriptionError(
+                "Description cannot be longer than 500 bytes",
+            ))?;
         }
 
         Ok(Ticket {