LL| |#![feature(coroutines, coroutine_trait)] | |
LL| | | |
LL| |use std::ops::{Coroutine, CoroutineState}; | |
LL| |use std::pin::Pin; | |
LL| | | |
LL| |// The following implementation of a function called from a `yield` statement | |
LL| |// (apparently requiring the Result and the `String` type or constructor) | |
LL| |// creates conditions where the `coroutine::StateTransform` MIR transform will | |
LL| |// drop all `Counter` `Coverage` statements from a MIR. `simplify.rs` has logic | |
LL| |// to handle this condition, and still report dead block coverage. | |
LL| 1|fn get_u32(val: bool) -> Result<u32, String> { | |
LL| 1| if val { Ok(1) } else { Err(String::from("some error")) } | |
^0 | |
LL| 1|} | |
LL| | | |
LL| 1|fn main() { | |
LL| 1| let is_true = std::env::args().len() == 1; | |
LL| 1| let mut coroutine = || { | |
LL| 1| yield get_u32(is_true); | |
LL| 1| return "foo"; | |
LL| 1| }; | |
LL| | | |
LL| 1| match Pin::new(&mut coroutine).resume(()) { | |
LL| 1| CoroutineState::Yielded(Ok(1)) => {} | |
LL| 0| _ => panic!("unexpected return from resume"), | |
LL| | } | |
LL| 1| match Pin::new(&mut coroutine).resume(()) { | |
LL| 1| CoroutineState::Complete("foo") => {} | |
LL| 0| _ => panic!("unexpected return from resume"), | |
LL| | } | |
LL| 1|} | |