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// Copyright 2017 The Rust Project Developers. See the COPYRIGHT
// file at the top-level directory of this distribution and at
// http://rust-lang.org/COPYRIGHT.
//
// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
// option. This file may not be copied, modified, or distributed
// except according to those terms.
#![feature(generators, generator_trait)]
use std::ops::{GeneratorState, Generator};
fn finish<T>(mut amt: usize, mut t: T) -> T::Return
where T: Generator<Yield = ()>
{
loop {
match unsafe { t.resume() } {
GeneratorState::Yielded(()) => amt = amt.checked_sub(1).unwrap(),
GeneratorState::Complete(ret) => {
assert_eq!(amt, 0);
return ret
}
}
}
}
fn main() {
finish(1, || yield);
finish(8, || {
for _ in 0..8 {
yield;
}
});
finish(1, || {
if true {
yield;
} else {
}
});
finish(1, || {
if false {
} else {
yield;
}
});
finish(2, || {
if { yield; false } {
yield;
panic!()
}
yield
});
}
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