54 lines
1.1 KiB
Rust
54 lines
1.1 KiB
Rust
// run-pass
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#![allow(unused_imports)]
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// A model for how the `Fn` traits could work. You can implement at
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// most one of `Go`, `GoMut`, or `GoOnce`, and then the others follow
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// automatically.
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// aux-build:go_trait.rs
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extern crate go_trait;
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use go_trait::{Go, GoMut, GoOnce, go, go_mut, go_once};
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use std::rc::Rc;
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use std::cell::Cell;
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struct SomeGoableThing {
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counter: Rc<Cell<isize>>
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}
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impl Go for SomeGoableThing {
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fn go(&self, arg: isize) {
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self.counter.set(self.counter.get() + arg);
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}
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}
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struct SomeGoOnceableThing {
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counter: Rc<Cell<isize>>
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}
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impl GoOnce for SomeGoOnceableThing {
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fn go_once(self, arg: isize) {
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self.counter.set(self.counter.get() + arg);
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}
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}
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fn main() {
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let counter = Rc::new(Cell::new(0));
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let mut x = SomeGoableThing { counter: counter.clone() };
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go(&x, 10);
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assert_eq!(counter.get(), 10);
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go_mut(&mut x, 100);
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assert_eq!(counter.get(), 110);
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go_once(x, 1_000);
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assert_eq!(counter.get(), 1_110);
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let x = SomeGoOnceableThing { counter: counter.clone() };
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go_once(x, 10_000);
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assert_eq!(counter.get(), 11_110);
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}
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