From 99f35197f3d37bc8f05146f67a67a7a11bed2194 Mon Sep 17 00:00:00 2001
From: Daniel Baraniak <dbaraniak2000@gmail.com>
Date: Mon, 11 Sep 2023 21:33:42 +0200
Subject: [PATCH] arc, box, rc

---
 exercises/smart_pointers/arc1.rs |  6 ++----
 exercises/smart_pointers/box1.rs |  8 +++-----
 exercises/smart_pointers/rc1.rs  | 14 ++++++--------
 3 files changed, 11 insertions(+), 17 deletions(-)

diff --git a/exercises/smart_pointers/arc1.rs b/exercises/smart_pointers/arc1.rs
index 3526ddcb..418616f7 100644
--- a/exercises/smart_pointers/arc1.rs
+++ b/exercises/smart_pointers/arc1.rs
@@ -21,19 +21,17 @@
 //
 // 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 = Arc::clone(&shared_numbers);
         joinhandles.push(thread::spawn(move || {
             let sum: u32 = child_numbers.iter().filter(|&&n| n % 8 == offset).sum();
             println!("Sum of offset {} is {}", offset, sum);
diff --git a/exercises/smart_pointers/box1.rs b/exercises/smart_pointers/box1.rs
index 513e7daa..df531fd0 100644
--- a/exercises/smart_pointers/box1.rs
+++ b/exercises/smart_pointers/box1.rs
@@ -18,11 +18,9 @@
 //
 // 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,
 }
 
@@ -35,11 +33,11 @@ fn main() {
 }
 
 pub fn create_empty_list() -> List {
-    todo!()
+    List::Nil
 }
 
 pub fn create_non_empty_list() -> List {
-    todo!()
+    List::Cons(0, Box::new(create_empty_list()))
 }
 
 #[cfg(test)]
diff --git a/exercises/smart_pointers/rc1.rs b/exercises/smart_pointers/rc1.rs
index 1b903469..f6e420a3 100644
--- a/exercises/smart_pointers/rc1.rs
+++ b/exercises/smart_pointers/rc1.rs
@@ -10,8 +10,6 @@
 //
 // Execute `rustlings hint rc1` or use the `hint` watch subcommand for a hint.
 
-// I AM NOT DONE
-
 use std::rc::Rc;
 
 #[derive(Debug)]
@@ -61,17 +59,17 @@ fn main() {
     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();
 
@@ -92,13 +90,13 @@ 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);