Update Exercises Directory Names to Reflect Order

1 files changed, 105 insertions, 0 deletions

diff --git a/exercises/19_smart_pointers/rc1.rs b/exercises/19_smart_pointers/rc1.rs
new file mode 100644
index 0000000..1b90346
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+++ b/exercises/19_smart_pointers/rc1.rs
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+// rc1.rs
+//
+// In this exercise, we want to express the concept of multiple owners via the
+// Rc<T> type. This is a model of our solar system - there is a Sun type and
+// multiple Planets. The Planets take ownership of the sun, indicating that they
+// revolve around the sun.
+//
+// Make this code compile by using the proper Rc primitives to express that the
+// sun has multiple owners.
+//
+// Execute `rustlings hint rc1` or use the `hint` watch subcommand for a hint.
+
+// I AM NOT DONE
+
+use std::rc::Rc;
+
+#[derive(Debug)]
+struct Sun {}
+
+#[derive(Debug)]
+enum Planet {
+    Mercury(Rc<Sun>),
+    Venus(Rc<Sun>),
+    Earth(Rc<Sun>),
+    Mars(Rc<Sun>),
+    Jupiter(Rc<Sun>),
+    Saturn(Rc<Sun>),
+    Uranus(Rc<Sun>),
+    Neptune(Rc<Sun>),
+}
+
+impl Planet {
+    fn details(&self) {
+        println!("Hi from {:?}!", self)
+    }
+}
+
+#[test]
+fn main() {
+    let sun = Rc::new(Sun {});
+    println!("reference count = {}", Rc::strong_count(&sun)); // 1 reference
+
+    let mercury = Planet::Mercury(Rc::clone(&sun));
+    println!("reference count = {}", Rc::strong_count(&sun)); // 2 references
+    mercury.details();
+
+    let venus = Planet::Venus(Rc::clone(&sun));
+    println!("reference count = {}", Rc::strong_count(&sun)); // 3 references
+    venus.details();
+
+    let earth = Planet::Earth(Rc::clone(&sun));
+    println!("reference count = {}", Rc::strong_count(&sun)); // 4 references
+    earth.details();
+
+    let mars = Planet::Mars(Rc::clone(&sun));
+    println!("reference count = {}", Rc::strong_count(&sun)); // 5 references
+    mars.details();
+
+    let jupiter = Planet::Jupiter(Rc::clone(&sun));
+    println!("reference count = {}", Rc::strong_count(&sun)); // 6 references
+    jupiter.details();
+
+    // TODO
+    let saturn = Planet::Saturn(Rc::new(Sun {}));
+    println!("reference count = {}", Rc::strong_count(&sun)); // 7 references
+    saturn.details();
+
+    // TODO
+    let uranus = Planet::Uranus(Rc::new(Sun {}));
+    println!("reference count = {}", Rc::strong_count(&sun)); // 8 references
+    uranus.details();
+
+    // TODO
+    let neptune = Planet::Neptune(Rc::new(Sun {}));
+    println!("reference count = {}", Rc::strong_count(&sun)); // 9 references
+    neptune.details();
+
+    assert_eq!(Rc::strong_count(&sun), 9);
+
+    drop(neptune);
+    println!("reference count = {}", Rc::strong_count(&sun)); // 8 references
+
+    drop(uranus);
+    println!("reference count = {}", Rc::strong_count(&sun)); // 7 references
+
+    drop(saturn);
+    println!("reference count = {}", Rc::strong_count(&sun)); // 6 references
+
+    drop(jupiter);
+    println!("reference count = {}", Rc::strong_count(&sun)); // 5 references
+
+    drop(mars);
+    println!("reference count = {}", Rc::strong_count(&sun)); // 4 references
+
+    // TODO
+    println!("reference count = {}", Rc::strong_count(&sun)); // 3 references
+
+    // TODO
+    println!("reference count = {}", Rc::strong_count(&sun)); // 2 references
+
+    // TODO
+    println!("reference count = {}", Rc::strong_count(&sun)); // 1 reference
+
+    assert_eq!(Rc::strong_count(&sun), 1);
+}