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1 | 1 | #![feature(generators, generator_trait, never_type)]
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2 | 2 |
|
3 |
| -use std::ops::{GeneratorState, Generator}; |
| 3 | +use std::ops::{GeneratorState::{self, *}, Generator}; |
4 | 4 | use std::pin::Pin;
|
| 5 | +use std::sync::atomic::{AtomicUsize, Ordering}; |
| 6 | +use std::fmt::Debug; |
5 | 7 |
|
6 |
| -fn finish<T>(mut amt: usize, mut t: T) -> T::Return |
7 |
| - where T: Generator<Yield = usize> |
8 |
| -{ |
9 |
| - // We are not moving the `t` around until it gets dropped, so this is okay. |
10 |
| - let mut t = unsafe { Pin::new_unchecked(&mut t) }; |
11 |
| - loop { |
12 |
| - match t.as_mut().resume() { |
13 |
| - GeneratorState::Yielded(y) => amt -= y, |
14 |
| - GeneratorState::Complete(ret) => { |
15 |
| - assert_eq!(amt, 0); |
16 |
| - return ret |
| 8 | +fn basic() { |
| 9 | + fn finish<T>(mut amt: usize, mut t: T) -> T::Return |
| 10 | + where T: Generator<Yield = usize> |
| 11 | + { |
| 12 | + // We are not moving the `t` around until it gets dropped, so this is okay. |
| 13 | + let mut t = unsafe { Pin::new_unchecked(&mut t) }; |
| 14 | + loop { |
| 15 | + match t.as_mut().resume(()) { |
| 16 | + GeneratorState::Yielded(y) => amt -= y, |
| 17 | + GeneratorState::Complete(ret) => { |
| 18 | + assert_eq!(amt, 0); |
| 19 | + return ret |
| 20 | + } |
17 | 21 | }
|
18 | 22 | }
|
19 | 23 | }
|
20 |
| -} |
21 | 24 |
|
22 |
| -enum Never {} |
23 |
| -fn never() -> Never { |
24 |
| - panic!() |
25 |
| -} |
| 25 | + enum Never {} |
| 26 | + fn never() -> Never { |
| 27 | + panic!() |
| 28 | + } |
26 | 29 |
|
27 |
| -fn main() { |
28 | 30 | finish(1, || yield 1);
|
29 | 31 |
|
30 | 32 | finish(3, || {
|
@@ -94,3 +96,93 @@ fn main() {
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94 | 96 | let _x: (String, !) = (String::new(), { yield 2; return });
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95 | 97 | });
|
96 | 98 | }
|
| 99 | + |
| 100 | +fn smoke_resume_arg() { |
| 101 | + fn drain<G: Generator<R, Yield = Y> + Unpin, R, Y>( |
| 102 | + gen: &mut G, |
| 103 | + inout: Vec<(R, GeneratorState<Y, G::Return>)>, |
| 104 | + ) where |
| 105 | + Y: Debug + PartialEq, |
| 106 | + G::Return: Debug + PartialEq, |
| 107 | + { |
| 108 | + let mut gen = Pin::new(gen); |
| 109 | + |
| 110 | + for (input, out) in inout { |
| 111 | + assert_eq!(gen.as_mut().resume(input), out); |
| 112 | + } |
| 113 | + } |
| 114 | + |
| 115 | + static DROPS: AtomicUsize = AtomicUsize::new(0); |
| 116 | + |
| 117 | + #[derive(Debug, PartialEq)] |
| 118 | + struct DropMe; |
| 119 | + |
| 120 | + impl Drop for DropMe { |
| 121 | + fn drop(&mut self) { |
| 122 | + DROPS.fetch_add(1, Ordering::SeqCst); |
| 123 | + } |
| 124 | + } |
| 125 | + |
| 126 | + fn expect_drops<T>(expected_drops: usize, f: impl FnOnce() -> T) -> T { |
| 127 | + DROPS.store(0, Ordering::SeqCst); |
| 128 | + |
| 129 | + let res = f(); |
| 130 | + |
| 131 | + let actual_drops = DROPS.load(Ordering::SeqCst); |
| 132 | + assert_eq!(actual_drops, expected_drops); |
| 133 | + res |
| 134 | + } |
| 135 | + |
| 136 | + drain( |
| 137 | + &mut |mut b| { |
| 138 | + while b != 0 { |
| 139 | + b = yield (b + 1); |
| 140 | + } |
| 141 | + -1 |
| 142 | + }, |
| 143 | + vec![(1, Yielded(2)), (-45, Yielded(-44)), (500, Yielded(501)), (0, Complete(-1))], |
| 144 | + ); |
| 145 | + |
| 146 | + expect_drops(2, || drain(&mut |a| yield a, vec![(DropMe, Yielded(DropMe))])); |
| 147 | + |
| 148 | + expect_drops(6, || { |
| 149 | + drain( |
| 150 | + &mut |a| yield yield a, |
| 151 | + vec![(DropMe, Yielded(DropMe)), (DropMe, Yielded(DropMe)), (DropMe, Complete(DropMe))], |
| 152 | + ) |
| 153 | + }); |
| 154 | + |
| 155 | + #[allow(unreachable_code)] |
| 156 | + expect_drops(2, || drain(&mut |a| yield return a, vec![(DropMe, Complete(DropMe))])); |
| 157 | + |
| 158 | + expect_drops(2, || { |
| 159 | + drain( |
| 160 | + &mut |a: DropMe| { |
| 161 | + if false { yield () } else { a } |
| 162 | + }, |
| 163 | + vec![(DropMe, Complete(DropMe))], |
| 164 | + ) |
| 165 | + }); |
| 166 | + |
| 167 | + expect_drops(4, || { |
| 168 | + drain( |
| 169 | + #[allow(unused_assignments, unused_variables)] |
| 170 | + &mut |mut a: DropMe| { |
| 171 | + a = yield; |
| 172 | + a = yield; |
| 173 | + a = yield; |
| 174 | + }, |
| 175 | + vec![ |
| 176 | + (DropMe, Yielded(())), |
| 177 | + (DropMe, Yielded(())), |
| 178 | + (DropMe, Yielded(())), |
| 179 | + (DropMe, Complete(())), |
| 180 | + ], |
| 181 | + ) |
| 182 | + }); |
| 183 | +} |
| 184 | + |
| 185 | +fn main() { |
| 186 | + basic(); |
| 187 | + smoke_resume_arg(); |
| 188 | +} |
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