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22 lines
579 B
22 lines
579 B
3 years ago
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enum List {
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Cons(i32, Rc<List>),
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Nil,
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}
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use crate::List::{Cons, Nil};
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use std::rc::Rc;
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// ANCHOR: here
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fn main() {
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let a = Rc::new(Cons(5, Rc::new(Cons(10, Rc::new(Nil)))));
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println!("count after creating a = {}", Rc::strong_count(&a));
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let b = Cons(3, Rc::clone(&a));
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println!("count after creating b = {}", Rc::strong_count(&a));
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{
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let c = Cons(4, Rc::clone(&a));
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println!("count after creating c = {}", Rc::strong_count(&a));
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}
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println!("count after c goes out of scope = {}", Rc::strong_count(&a));
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}
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// ANCHOR_END: here
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