finish

Change-Id: I982b607976e26bf3bea46f726b381e67256cc47a

exercises/clippy/clippy1.rs

@@ -6,12 +6,11 @@
 // check clippy's suggestions from the output to solve the exercise.
 // Execute `rustlings hint clippy1` or use the `hint` watch subcommand for a hint.
 
-// I AM NOT DONE
-
 use std::f32;
+use std::f32::consts::PI;
 
 fn main() {
-    let pi = 3.14f32;
+    let pi = PI;
     let radius = 5.00f32;
 
     let area = pi * f32::powi(radius, 2);

exercises/clippy/clippy2.rs

@@ -1,13 +1,11 @@
 // clippy2.rs
 // Execute `rustlings hint clippy2` or use the `hint` watch subcommand for a hint.
 
-// I AM NOT DONE
-
 fn main() {
     let mut res = 42;
     let option = Some(12);
-    for x in option {
-        res += x;
+    if let Some(n) = option {
+        res += n;
     }
     println!("{}", res);
 }

exercises/clippy/clippy3.rs

@@ -1,28 +1,27 @@
 // clippy3.rs
 // Here's a couple more easy Clippy fixes, so you can see its utility.
 
-// I AM NOT DONE
+use std::mem::swap;
 
 #[allow(unused_variables, unused_assignments)]
 fn main() {
     let my_option: Option<()> = None;
-    if my_option.is_none() {
-        my_option.unwrap();
+    if let Some(o) = my_option {
+        println!("{:?}", o)
     }
 
     let my_arr = &[
-        -1, -2, -3
+        -1, -2, -3,
         -4, -5, -6
     ];
     println!("My array! Here it is: {:?}", my_arr);
-
-    let my_empty_vec = vec![1, 2, 3, 4, 5].resize(0, 5);
+    let mut my_empty_vec = vec![1, 2, 3, 4, 5];
+    my_empty_vec.clear();
     println!("This Vec is empty, see? {:?}", my_empty_vec);
 
     let mut value_a = 45;
     let mut value_b = 66;
     // Let's swap these two!
-    value_a = value_b;
-    value_b = value_a;
+    swap(&mut value_a, &mut value_b);
     println!("value a: {}; value b: {}", value_a, value_b);
 }

exercises/macros/macros1.rs

@@ -1,8 +1,6 @@
 // macros1.rs
 // Execute `rustlings hint macros1` or use the `hint` watch subcommand for a hint.
 
-// I AM NOT DONE
-
 macro_rules! my_macro {
     () => {
         println!("Check out my macro!");
@@ -10,5 +8,5 @@ macro_rules! my_macro {
 }
 
 fn main() {
-    my_macro();
+    my_macro!();
 }

exercises/macros/macros2.rs

@@ -1,14 +1,12 @@
 // macros2.rs
 // Execute `rustlings hint macros2` or use the `hint` watch subcommand for a hint.
 
-// I AM NOT DONE
-
-fn main() {
-    my_macro!();
-}
-
 macro_rules! my_macro {
     () => {
         println!("Check out my macro!");
     };
 }
+
+fn main() {
+    my_macro!();
+}

exercises/macros/macros3.rs

@@ -2,9 +2,8 @@
 // Make me compile, without taking the macro out of the module!
 // Execute `rustlings hint macros3` or use the `hint` watch subcommand for a hint.
 
-// I AM NOT DONE
-
 mod macros {
+    #[macro_export]
     macro_rules! my_macro {
         () => {
             println!("Check out my macro!");

exercises/macros/macros4.rs

@@ -1,16 +1,14 @@
 // macros4.rs
 // Execute `rustlings hint macros4` or use the `hint` watch subcommand for a hint.
 
-// I AM NOT DONE
-
 #[rustfmt::skip]
 macro_rules! my_macro {
     () => {
         println!("Check out my macro!");
-    }
+    };
     ($val:expr) => {
         println!("Look at this other macro: {}", $val);
-    }
+    };
 }
 
 fn main() {

exercises/smart_pointers/arc1.rs

@@ -18,19 +18,17 @@
 // where the second TODO comment is. Try not to create any copies of the `numbers` Vec!
 // Execute `rustlings hint arc1` or use the `hint` watch subcommand for a hint.
 
-// I AM NOT DONE
-
 #![forbid(unused_imports)] // Do not change this, (or the next) line.
 use std::sync::Arc;
 use std::thread;
 
 fn main() {
     let numbers: Vec<_> = (0..100u32).collect();
-    let shared_numbers = // TODO
+    let shared_numbers = Arc::new(numbers);
     let mut joinhandles = Vec::new();
 
     for offset in 0..8 {
-        let child_numbers = // TODO
+        let child_numbers = shared_numbers.clone();
         joinhandles.push(thread::spawn(move || {
             let sum: u32 = child_numbers.iter().filter(|&&n| n % 8 == offset).sum();
             println!("Sum of offset {} is {}", offset, sum);

exercises/smart_pointers/box1.rs

@@ -16,11 +16,9 @@
 //
 // Execute `rustlings hint box1` or use the `hint` watch subcommand for a hint.
 
-// I AM NOT DONE
-
 #[derive(PartialEq, Debug)]
 pub enum List {
-    Cons(i32, List),
+    Cons(i32, Box<List>),
     Nil,
 }
 
@@ -33,11 +31,11 @@ fn main() {
 }
 
 pub fn create_empty_list() -> List {
-    todo!()
+    List::Nil
 }
 
 pub fn create_non_empty_list() -> List {
-    todo!()
+    List::Cons(1, Box::new(List::Nil))
 }
 
 #[cfg(test)]

exercises/smart_pointers/cow1.rs

@@ -8,8 +8,6 @@
 // This exercise is meant to show you what to expect when passing data to Cow.
 // Fix the unit tests by checking for Cow::Owned(_) and Cow::Borrowed(_) at the TODO markers.
 
-// I AM NOT DONE
-
 use std::borrow::Cow;
 
 fn abs_all<'a, 'b>(input: &'a mut Cow<'b, [i32]>) -> &'a mut Cow<'b, [i32]> {
@@ -43,8 +41,10 @@ mod tests {
         // No clone occurs because `input` doesn't need to be mutated.
         let slice = [0, 1, 2];
         let mut input = Cow::from(&slice[..]);
+        // there's no to_mut() invoked because of the elements of slice has no negative number
         match abs_all(&mut input) {
-            // TODO
+            Cow::Borrowed(_) => Ok(()),
+            _ => Err("Expected borrowed value"),
         }
     }
 
@@ -57,7 +57,8 @@ mod tests {
         let slice = vec![0, 1, 2];
         let mut input = Cow::from(slice);
         match abs_all(&mut input) {
-            // TODO
+            Cow::Owned(_) => Ok(()),
+            _ => Err("Expected owned value"),
         }
     }
 
@@ -69,7 +70,8 @@ mod tests {
         let slice = vec![-1, 0, 1];
         let mut input = Cow::from(slice);
         match abs_all(&mut input) {
-            // TODO
+            Cow::Owned(_) => Ok(()),
+            _ => Err("Expected owned value"),
         }
     }
 }

exercises/smart_pointers/rc1.rs

@@ -5,8 +5,6 @@
 
 // Make this code compile by using the proper Rc primitives to express that the sun has multiple owners.
 
-// I AM NOT DONE
-
 use std::rc::Rc;
 
 #[derive(Debug)]
@@ -54,18 +52,15 @@ fn main() {
     println!("reference count = {}", Rc::strong_count(&sun)); // 6 references
     jupiter.details();
 
-    // TODO
-    let saturn = Planet::Saturn(Rc::new(Sun {}));
+    let saturn = Planet::Saturn(Rc::clone(&sun));
     println!("reference count = {}", Rc::strong_count(&sun)); // 7 references
     saturn.details();
 
-    // TODO
-    let uranus = Planet::Uranus(Rc::new(Sun {}));
+    let uranus = Planet::Uranus(Rc::clone(&sun));
     println!("reference count = {}", Rc::strong_count(&sun)); // 8 references
     uranus.details();
 
-    // TODO
-    let neptune = Planet::Neptune(Rc::new(Sun {}));
+    let neptune = Planet::Neptune(Rc::clone(&sun));
     println!("reference count = {}", Rc::strong_count(&sun)); // 9 references
     neptune.details();
 
@@ -86,13 +81,13 @@ fn main() {
     drop(mars);
     println!("reference count = {}", Rc::strong_count(&sun)); // 4 references
 
-    // TODO
+    drop(earth);
     println!("reference count = {}", Rc::strong_count(&sun)); // 3 references
 
-    // TODO
+    drop(venus);
     println!("reference count = {}", Rc::strong_count(&sun)); // 2 references
 
-    // TODO
+    drop(mercury);
     println!("reference count = {}", Rc::strong_count(&sun)); // 1 reference
 
     assert_eq!(Rc::strong_count(&sun), 1);

exercises/threads/threads1.rs

@@ -6,8 +6,6 @@
 // The program should wait until all the spawned threads have finished and
 // should collect their return values into a vector.
 
-// I AM NOT DONE
-
 use std::thread;
 use std::time::{Duration, Instant};
 
@@ -24,7 +22,7 @@ fn main() {
 
     let mut results: Vec<u128> = vec![];
     for handle in handles {
-        // TODO: a struct is returned from thread::spawn, can you use it?
+        results.push(handle.join().unwrap_or(0));
     }
 
     if results.len() != 10 {

exercises/threads/threads2.rs

@@ -3,9 +3,7 @@
 // Building on the last exercise, we want all of the threads to complete their work but this time
 // the spawned threads need to be in charge of updating a shared value: JobStatus.jobs_completed
 
-// I AM NOT DONE
-
-use std::sync::Arc;
+use std::sync::{Arc, Mutex};
 use std::thread;
 use std::time::Duration;
 
@@ -14,21 +12,18 @@ struct JobStatus {
 }
 
 fn main() {
-    let status = Arc::new(JobStatus { jobs_completed: 0 });
+    let status = Arc::new(Mutex::new(JobStatus { jobs_completed: 0 }));
     let mut handles = vec![];
     for _ in 0..10 {
         let status_shared = Arc::clone(&status);
         let handle = thread::spawn(move || {
             thread::sleep(Duration::from_millis(250));
-            // TODO: You must take an action before you update a shared value
-            status_shared.jobs_completed += 1;
+            status_shared.lock().unwrap().jobs_completed += 1;
         });
         handles.push(handle);
     }
     for handle in handles {
         handle.join().unwrap();
-        // TODO: Print the value of the JobStatus.jobs_completed. Did you notice anything
-        // interesting in the output? Do you have to 'join' on all the handles?
-        println!("jobs completed {}", ???);
+        println!("jobs completed {}", status.lock().unwrap().jobs_completed)
     }
 }

exercises/threads/threads3.rs

@@ -1,8 +1,6 @@
 // threads3.rs
 // Execute `rustlings hint threads3` or use the `hint` watch subcommand for a hint.
 
-// I AM NOT DONE
-
 use std::sync::mpsc;
 use std::sync::Arc;
 use std::thread;
@@ -29,10 +27,13 @@ fn send_tx(q: Queue, tx: mpsc::Sender<u32>) -> () {
     let qc1 = Arc::clone(&qc);
     let qc2 = Arc::clone(&qc);
 
+    let sender1 = tx.clone();
+    let sender2 = tx.clone();
+
     thread::spawn(move || {
         for val in &qc1.first_half {
             println!("sending {:?}", val);
-            tx.send(*val).unwrap();
+            sender1.send(*val).unwrap();
             thread::sleep(Duration::from_secs(1));
         }
     });
@@ -40,7 +41,7 @@ fn send_tx(q: Queue, tx: mpsc::Sender<u32>) -> () {
     thread::spawn(move || {
         for val in &qc2.second_half {
             println!("sending {:?}", val);
-            tx.send(*val).unwrap();
+            sender2.send(*val).unwrap();
             thread::sleep(Duration::from_secs(1));
         }
     });