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