| #![feature(generators, generator_trait)] |
| |
| use std::{ |
| cell::RefCell, |
| sync::Arc, |
| pin::Pin, |
| ops::{Generator, GeneratorState}, |
| }; |
| |
| pub struct Ready<T>(Option<T>); |
| impl<T: Unpin> Generator<()> for Ready<T> { |
| type Return = T; |
| type Yield = (); |
| fn resume(mut self: Pin<&mut Self>, _args: ()) -> GeneratorState<(), T> { |
| GeneratorState::Complete(self.0.take().unwrap()) |
| } |
| } |
| pub fn make_gen1<T>(t: T) -> Ready<T> { |
| Ready(Some(t)) |
| } |
| |
| fn require_send(_: impl Send) {} |
| //~^ NOTE required by a bound |
| //~| NOTE required by a bound |
| //~| NOTE required by this bound |
| //~| NOTE required by this bound |
| |
| fn make_non_send_generator() -> impl Generator<Return = Arc<RefCell<i32>>> { |
| make_gen1(Arc::new(RefCell::new(0))) |
| } |
| |
| fn test1() { |
| let send_gen = || { |
| let _non_send_gen = make_non_send_generator(); |
| //~^ NOTE not `Send` |
| yield; |
| //~^ NOTE yield occurs here |
| //~| NOTE value is used across a yield |
| }; |
| require_send(send_gen); |
| //~^ ERROR generator cannot be sent between threads |
| //~| NOTE not `Send` |
| //~| NOTE use `std::sync::RwLock` instead |
| } |
| |
| pub fn make_gen2<T>(t: T) -> impl Generator<Return = T> { |
| //~^ NOTE appears within the type |
| //~| NOTE expansion of desugaring |
| || { //~ NOTE used within this generator |
| yield; |
| t |
| } |
| } |
| fn make_non_send_generator2() -> impl Generator<Return = Arc<RefCell<i32>>> { //~ NOTE appears within the type |
| //~^ NOTE expansion of desugaring |
| make_gen2(Arc::new(RefCell::new(0))) |
| } |
| |
| fn test2() { |
| let send_gen = || { //~ NOTE used within this generator |
| let _non_send_gen = make_non_send_generator2(); |
| yield; |
| }; |
| require_send(send_gen); |
| //~^ ERROR `RefCell<i32>` cannot be shared between threads safely |
| //~| NOTE `RefCell<i32>` cannot be shared between threads safely |
| //~| NOTE required for |
| //~| NOTE captures the following types |
| //~| NOTE use `std::sync::RwLock` instead |
| } |
| |
| fn main() {} |