mirror of
https://github.com/notohh/rustlings.git
synced 2024-11-23 14:12:23 -05:00
4771a7b9e7
Missed a blank line, which causes the prompt incorrect like below: ```rust You can keep working on this exercise, or jump into the next one by removing the `I AM NOT DONE` comment: 6 | // Make this code compile by using the proper Rc primitives to express that the sun has multiple owners. 7 | 8 | // I AM NOT DONE 9 | use std::rc::Rc; ```
99 lines
2.9 KiB
Rust
99 lines
2.9 KiB
Rust
// 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.
|
|
|
|
// 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)
|
|
}
|
|
}
|
|
|
|
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);
|
|
}
|