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//@ check-pass
//@ edition:2021
#![allow(unreachable_code)]
use std::fmt::{self, Display};
use std::marker::PhantomData;
struct NotSend {
marker: PhantomData<*const u8>,
}
const NOT_SEND: NotSend = NotSend { marker: PhantomData };
impl Display for NotSend {
fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
formatter.write_str("this value does not implement Send")
}
}
async fn f(_: u8) {}
// Exercises this matcher in panic_2021:
// ($($t:tt)+) => $crate::panicking::panic_fmt(...)
async fn panic_fmt() {
// Panic returns `!`, so the await is never reached, and in particular the
// temporaries inside the formatting machinery are not still alive at the
// await point.
let todo = "...";
f(panic!("not yet implemented: {}", todo)).await;
}
// Exercises ("{}", $arg:expr) => $crate::panicking::panic_display(&$arg)
async fn panic_display() {
f(panic!("{}", NOT_SEND)).await;
}
fn require_send(_: impl Send) {}
fn main() {
require_send(panic_fmt());
require_send(panic_display());
}
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