solution to exercise 04_05

Co-authored-by: Felix Pherry <182051.FELIX@klgroup.local>

Cargo.toml

@@ -1,3 +1,6 @@
 [workspace]
 members = ["exercises/*/*", "helpers/common", "helpers/mdbook-exercise-linker", "helpers/ticket_fields"]
 resolver = "2"
+
+[profile.dev]
+overflow-checks = false

book/src/03_ticket_v1/06_ownership.md

@@ -95,8 +95,8 @@ Ownership can be transferred.
 If you own a value, for example, you can transfer ownership to another variable:
 
 ```rust
-let a = 42; // <--- `a` is the owner of the value `42`
-let b = a;  // <--- `b` is now the owner of the value `42`
+let a = "hello, world".to_string(); // <--- `a` is the owner of the String
+let b = a;  // <--- `b` is now the owner of the String
 ```
 
 Rust's ownership system is baked into the type system: each function has to declare in its signature

book/src/04_traits/04_derive.md

@@ -58,7 +58,7 @@ You've already encountered a few macros in past exercises:
 Rust macros are **code generators**.\
 They generate new Rust code based on the input you provide, and that generated code is then compiled alongside
 the rest of your program. Some macros are built into Rust's standard library, but you can also
-write your own. We won't be creating our macro in this course, but you can find some useful
+write your own. We won't be creating our own macro in this course, but you can find some useful
 pointers in the ["Further reading" section](#further-reading).
 
 ### Inspection

book/src/04_traits/05_trait_bounds.md

@@ -58,7 +58,7 @@ We can do better using **generics**.\
 Generics allow us to write code that works with a **type parameter** instead of a concrete type:
 
 ```rust
-fn print_if_even<T>(n: T) 
+fn print_if_even<T>(n: T)
 where
     T: IsEven + Debug
 {
@@ -125,7 +125,7 @@ body is present.
 All the examples above used a **`where` clause** to specify trait bounds:
 
 ```rust
-fn print_if_even<T>(n: T) 
+fn print_if_even<T>(n: T)
 where
     T: IsEven + Debug
 //  ^^^^^^^^^^^^^^^^^
@@ -160,7 +160,7 @@ fn print_if_even<Number: IsEven + Debug>(n: Number) {
 It is actually **desirable** to use meaningful names when there are multiple type parameters at play or when the name
 `T` doesn't convey enough information about the type's role in the function.
 Maximize clarity and readability when naming type parameters, just as you would with variables or function parameters.
-Follow Rust's conventions though: use camel case for type parameter names.
+Follow Rust's conventions, though: use [upper camel case for type parameter names](https://rust-lang.github.io/api-guidelines/naming.html#casing-conforms-to-rfc-430-c-case).
 
 ## The function signature is king
 

book/src/05_ticket_v2/05_nullability.md

@@ -51,7 +51,7 @@ let y = point.1;
 
 ### Tuples
 
-It's weird say that something is tuple-like when we haven't seen tuples yet!\
+It's weird to say that something is tuple-like when we haven't seen tuples yet!\
 Tuples are another example of a primitive Rust type.
 They group together a fixed number of values with (potentially different) types:
 

book/src/05_ticket_v2/09_error_trait.md

@@ -2,12 +2,12 @@
 
 ## Error reporting
 
-In the previous exercise you had to destructure the `InvalidTitle` variant to extract the error message and
+In the previous exercise you had to destructure the `TitleError` variant to extract the error message and
 pass it to the `panic!` macro.\
 This is a (rudimentary) example of **error reporting**: transforming an error type into a representation that can be
 shown to a user, a service operator, or a developer.
 
-It's not practical for each Rust developer to come up with their own error reporting strategy: it'd a waste of time
+It's not practical for each Rust developer to come up with their own error reporting strategy: it'd be a waste of time
 and it wouldn't compose well across projects.
 That's why Rust provides the `std::error::Error` trait.
 

book/src/06_ticket_management/02_vec.md

@@ -66,7 +66,7 @@ assert_eq!(numbers.get(0), Some(&1));
 assert_eq!(numbers.get(3), None);
 ```
 
-Access is bounds-checked, just element access with arrays. It has O(1) complexity.
+Access is bounds-checked, just like element access with arrays. It has O(1) complexity.
 
 ## Memory layout
 

book/src/07_threads/00_intro.md

@@ -12,4 +12,4 @@ We'll have the opportunity to touch most of Rust's core concurrency features, in
 - Shared state, using `Arc`, `Mutex` and `RwLock`
 - `Send` and `Sync`, the traits that encode Rust's concurrency guarantees
 
-We'll also discuss various design patterns for multithreaded systems and some their trade-offs.
+We'll also discuss various design patterns for multithreaded systems and some of their trade-offs.

book/src/07_threads/11_locks.md

@@ -74,7 +74,7 @@ struct TicketStore {
 ```
 
 This approach is more efficient, but it has a downside: `TicketStore` has to become **aware** of the multithreaded
-nature of the system; up until now, `TicketStore` has been blissfully ignored the existence of threads.\
+nature of the system; up until now, `TicketStore` has been blissfully ignoring the existence of threads.\
 Let's go for it anyway.
 
 ## Who holds the lock?

book/src/07_threads/13_without_channels.md

@@ -48,7 +48,7 @@ If we remove the channels, we need to introduce (another) lock to synchronize ac
 
 If we use a `Mutex`, then it makes no sense to use an additional `RwLock` for each ticket: the `Mutex` will
 already serialize access to the entire store, so we wouldn't be able to read tickets in parallel anyway.\
-If we use a `RwLock`, instead, we can read tickets in parallel. We just to pause all reads while inserting
+If we use a `RwLock`, instead, we can read tickets in parallel. We just need to pause all reads while inserting
 or removing a ticket.
 
 Let's go down this path and see where it leads us.

book/src/08_futures/02_spawn.md

@@ -99,7 +99,7 @@ pub async fn run() {
         if let Ok(reason) = e.try_into_panic() {
             // The task has panicked
             // We resume unwinding the panic,
-            // thus propagating it to the current thread
+            // thus propagating it to the current task
             panic::resume_unwind(reason);
         }
     }

book/src/going_further.md

@@ -28,8 +28,7 @@ project and on [exercism.io](https://exercism.io)'s Rust track.
 Check out [the Rust book](https://doc.rust-lang.org/book/title-page.html) and
 ["Programming Rust"](https://www.oreilly.com/library/view/programming-rust-2nd/9781492052586/)
 if you're looking for a different perspective on the same concepts we covered throughout this course.
-The material doesn't overlap perfectly, therefore you'll certainly learn something new along the
-way.
+You'll certainly learn something new since they don't cover exactly the same topics; Rust has a lot of surface area!
 
 ### Advanced material
 

exercises/01_intro/00_welcome/src/lib.rs

@@ -17,7 +17,7 @@
 // You can also find solutions to all exercises in the `solutions` git branch.
 fn greeting() -> &'static str {
     // TODO: fix me 👇
-    "I'm ready to __!"
+    "I'm ready to learn Rust!"
 }
 
 // Your solutions will be automatically verified by a set of tests.

exercises/01_intro/01_syntax/src/lib.rs

@@ -3,7 +3,7 @@
 //  partner in this course and it'll often guide you in the right direction!
 //
 // The input parameters should have the same type of the return type.
-fn compute(a, b) -> u32 {
+fn compute(a: u32, b: u32) -> u32 {
     // Don't touch the function body.
     a + b * 2
 }
@@ -16,4 +16,4 @@ mod tests {
     fn case() {
         assert_eq!(compute(1, 2), 5);
     }
-}
+}

exercises/02_basic_calculator/00_intro/src/lib.rs

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

exercises/02_basic_calculator/01_integers/src/lib.rs

@@ -1,6 +1,6 @@
 fn compute(a: u32, b: u32) -> u32 {
     // TODO: change the line below to fix the compiler error and make the tests pass.
-    a + b * 4u8
+    a + b * 4u32
 }
 
 #[cfg(test)]

exercises/02_basic_calculator/02_variables/src/lib.rs

@@ -8,7 +8,7 @@
 pub fn speed(start: u32, end: u32, time_elapsed: u32) -> u32 {
     // TODO: define a variable named `distance` with the right value to get tests to pass
     //  Do you need to annotate the type of `distance`? Why or why not?
-
+    let distance: u32 = end - start;
     // Don't change the line below
     distance / time_elapsed
 }

exercises/02_basic_calculator/03_if_else/src/lib.rs

@@ -1,6 +1,6 @@
 /// Return `true` if `n` is even, `false` otherwise.
 fn is_even(n: u32) -> bool {
-    todo!()
+    n % 2 == 0
 }
 
 #[cfg(test)]

exercises/02_basic_calculator/04_panics/src/lib.rs

@@ -2,7 +2,9 @@
 /// calculate the average speed of the journey.
 fn speed(start: u32, end: u32, time_elapsed: u32) -> u32 {
     // TODO: Panic with a custom message if `time_elapsed` is 0
-
+    if time_elapsed == 0 {
+        panic!("The journey took no time at all, that's impossible!");
+    }
     (end - start) / time_elapsed
 }
 

exercises/02_basic_calculator/05_factorial/src/lib.rs

@@ -9,6 +9,13 @@
 // `factorial(2)` to return `2`, and so on.
 //
 // Use only what you learned! No loops yet, so you'll have to use recursion!
+fn factorial(n: u16) -> u16 {
+    if n == 0 {
+        1
+    } else {
+        n * factorial(n - 1)
+    }
+}
 
 #[cfg(test)]
 mod tests {

exercises/02_basic_calculator/06_while/src/lib.rs

@@ -4,7 +4,13 @@ pub fn factorial(n: u32) -> u32 {
     // interprets as "I'll get back to this later", thus
     // suppressing type errors.
     // It panics at runtime.
-    todo!()
+    let mut result: u32 = 1; // base case
+    let mut i: u32 = 1;
+    while i <= n {
+        result *= i;
+        i += 1;
+    }
+    result
 }
 
 #[cfg(test)]

exercises/02_basic_calculator/07_for/src/lib.rs

@@ -1,6 +1,10 @@
 // Rewrite the factorial function using a `for` loop.
 pub fn factorial(n: u32) -> u32 {
-    todo!()
+    let mut result: u32 = 1; // base case
+    for i in 2..=n {
+        result *= i;
+    }
+    result
 }
 
 #[cfg(test)]

exercises/02_basic_calculator/09_saturating/src/lib.rs

@@ -1,9 +1,9 @@
 pub fn factorial(n: u32) -> u32 {
-    let mut result = 1;
+    let mut result: u32 = 1;
     for i in 1..=n {
         // Use saturating multiplication to stop at the maximum value of u32
         // rather than overflowing and wrapping around
-        result *= i;
+        result = result.saturating_mul(i);
     }
     result
 }

exercises/02_basic_calculator/10_as_casting/src/lib.rs

@@ -6,7 +6,7 @@ mod tests {
 
     #[test]
     fn u16_to_u32() {
-        let v: u32 = todo!();
+        let v: u32 = 47;
         assert_eq!(47u16 as u32, v);
     }
 
@@ -24,14 +24,14 @@ mod tests {
         // You could solve this by using exactly the same expression as above,
         // but that would defeat the purpose of the exercise. Instead, use a genuine
         // `i8` value that is equivalent to `255` when converted from `u8`.
-        let y: i8 = todo!();
+        let y: i8 = -1;
 
         assert_eq!(x, y);
     }
 
     #[test]
     fn bool_to_u8() {
-        let v: u8 = todo!();
+        let v: u8 = 1;
         assert_eq!(true as u8, v);
     }
 }

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)]

exercises/03_ticket_v1/01_struct/src/lib.rs

@@ -4,6 +4,16 @@
 //
 // 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 {

exercises/03_ticket_v1/02_validation/src/lib.rs

@@ -17,7 +17,22 @@ 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 status != "To-Do" && status != "In Progress" && status != "Done" {
+            panic!("Only `To-Do`, `In Progress`, and `Done` statuses are allowed")
+        }
+        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")
+        }
+
         Self {
             title,
             description,

exercises/03_ticket_v1/03_modules/src/lib.rs

@@ -1,6 +1,7 @@
 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 super::Ticket;
 
     fn create_todo_ticket(title: String, description: String) -> Ticket {
         Ticket::new(title, description, "To-Do".into())

exercises/03_ticket_v1/04_visibility/src/lib.rs

@@ -1,12 +1,12 @@
 mod ticket {
-    struct Ticket {
+    pub struct Ticket {
         title: String,
         description: String,
         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");
             }
@@ -55,7 +55,7 @@ mod tests {
         //
         // TODO: Once you have verified that the below does not compile,
         //   comment the line out to move on to the next exercise!
-        assert_eq!(ticket.description, "A description");
+        // assert_eq!(ticket.description, "A description");
     }
 
     fn encapsulation_cannot_be_violated() {
@@ -68,10 +68,10 @@ mod tests {
         //
         // TODO: Once you have verified that the below does not compile,
         //   comment the lines out to move on to the next exercise!
-        let ticket = Ticket {
-            title: "A title".into(),
-            description: "A description".into(),
-            status: "To-Do".into(),
-        };
+        // let ticket = Ticket {
+        //    title: "A title".into(),
+        //    description: "A description".into(),
+        //    status: "To-Do".into(),
+        // };
     }
 }

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 title(self) -> String {
+            self.title
+        }
+
+        pub fn description(self) -> String {
+            self.description
+        }
+
+        pub fn status(self) -> String {
+            self.status
+        }
     }
 }
 

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) -> &String {
+        &self.title
     }
 
-    pub fn description(self) -> String {
-        self.description
+    pub fn description(&self) -> &String {
+        &self.description
     }
 
-    pub fn status(self) -> String {
-        self.status
+    pub fn status(&self) -> &String {
+        &self.status
     }
 }
 

exercises/03_ticket_v1/07_setters/src/lib.rs

@@ -11,21 +11,9 @@ 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");
-        }
+        validate_title(&title);
+        validate_description(&description);
+        validate_status(&status);
 
         Ticket {
             title,
@@ -45,6 +33,45 @@ impl Ticket {
     pub fn status(&self) -> &String {
         &self.status
     }
+
+    pub fn set_title(&mut self, title: String) {
+        validate_title(&title);
+        self.title = title;
+    }
+
+    pub fn set_description(&mut self, description: String) {
+        validate_description(&description);
+        self.description = description;
+    }
+
+    pub fn set_status(&mut self, status: String) {
+        validate_status(&status);
+        self.status = status;
+    }
+}
+
+fn validate_title(title: &String) {
+    if title.is_empty() {
+        panic!("Title cannot be empty");
+    }
+    if title.len() > 50 {
+        panic!("Title cannot be longer than 50 bytes");
+    }
+}
+
+fn validate_description(description: &String) {
+    if description.is_empty() {
+        panic!("Description cannot be empty");
+    }
+    if description.len() > 500 {
+        panic!("Description cannot be longer than 500 bytes");
+    }
+}
+
+fn validate_status(status: &String) {
+    if status != "To-Do" && status != "In Progress" && status != "Done" {
+        panic!("Only `To-Do`, `In Progress`, and `Done` statuses are allowed");
+    }
 }
 
 #[cfg(test)]

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);
     }
 }

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);
     }
 }

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);
     }
 }

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)]

exercises/03_ticket_v1/12_outro/src/lib.rs

@@ -11,3 +11,74 @@
 // 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.
+pub struct Order {
+    product_name: String,
+    quantity: u32,
+    unit_price: u32,
+}
+
+impl Order {
+    pub fn new(product_name: String, quantity: u32, unit_price: u32) -> Order {
+        validate_product_name(&product_name);
+        validate_quantity(&quantity);
+        validate_unit_price(&unit_price);
+
+        Order {
+            product_name,
+            quantity,
+            unit_price,
+        }
+    }
+
+    pub fn product_name(&self) -> &String {
+        &self.product_name
+    }
+
+    pub fn quantity(&self) -> &u32 {
+        &self.quantity
+    }
+
+    pub fn unit_price(&self) -> &u32 {
+        &self.unit_price
+    }
+
+    pub fn set_product_name(&mut self, product_name: String) {
+        validate_product_name(&product_name);
+        self.product_name = product_name;
+    }
+
+    pub fn set_quantity(&mut self, quantity: u32) {
+        validate_quantity(&quantity);
+        self.quantity = quantity;
+    }
+
+    pub fn set_unit_price(&mut self, unit_price: u32) {
+        validate_unit_price(&unit_price);
+        self.unit_price = unit_price;
+    }
+
+    pub fn total(&self) -> u32 {
+        self.quantity * self.unit_price
+    }
+}
+
+fn validate_product_name(product_name: &String) {
+    if product_name.is_empty() {
+        panic!("Product name cannot be empty");
+    }
+    if product_name.len() > 300 {
+        panic!("Product name cannot be longer than 300 bytes");
+    }
+}
+
+fn validate_quantity(quantity: &u32) {
+    if quantity == &0 {
+        panic!("Quantity must be greater than zero");
+    }
+}
+
+fn validate_unit_price(unit_price: &u32) {
+    if unit_price == &0 {
+        panic!("Unit price must be greater than zero");
+    }
+}

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 {

exercises/07_threads/01_threads/src/lib.rs

@@ -8,7 +8,7 @@
 // You _could_ pass this test by just returning `v.iter().sum()`,
 // but that would defeat the purpose of the exercise.
 //
-// Hint: you won't be able to get the spawn threads to _borrow_
+// Hint: you won't be able to get the spawned threads to _borrow_
 // slices of the vector directly. You'll need to allocate new
 // vectors for each half of the original vector. We'll see why
 // this is necessary in the next exercise.

exercises/07_threads/05_channels/tests/insert.rs

@@ -1,3 +1,5 @@
+// TODO: Set `move_forward` to `true` in `ready` when you think you're done with this exercise.
+//  Feel free to call an instructor to verify your solution!
 use channels::data::TicketDraft;
 use channels::{launch, Command};
 use std::time::Duration;
@@ -24,8 +26,6 @@ fn ready() {
     // since our server doesn't expose any **read** actions.
     // We have no way to know if the inserts are actually happening and if they
     // are happening correctly.
-    // Set `move_forward` to `true` when you think you're done with this exercise.
-    // Feel free to call an instructor to verify your solution!
     let move_forward = false;
 
     assert!(move_forward);