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