tests/ui/macros/format-args-temporaries-async.rs

   1 // check-pass
   2 // edition:2021
   3
   4 use std::fmt::{self, Display};
   5 use std::future::Future;
   6 use std::io;
   7 use std::pin::Pin;
   8 use std::task::{Context, Poll};
   9
  10 struct AsyncStdout;
  11
  12 impl AsyncStdout {
  13     fn write_fmt<'a>(&'a mut self, _args: fmt::Arguments) -> WriteFmtFuture<'a, Self>
  14     where
  15         Self: Unpin,
  16     {
  17         WriteFmtFuture(self)
  18     }
  19 }
  20
  21 struct WriteFmtFuture<'a, T>(&'a mut T);
  22
  23 impl<'a, T> Future for WriteFmtFuture<'a, T> {
  24     type Output = io::Result<()>;
  25     fn poll(self: Pin<&mut Self>, cx: &mut Context) -> Poll<Self::Output> {
  26         unimplemented!()
  27     }
  28 }
  29
  30 async fn async_main() {
  31     let _write = write!(&mut AsyncStdout, "...").await;
  32     let _writeln = writeln!(&mut AsyncStdout, "...").await;
  33 }
  34
  35 fn main() {
  36     let _ = async_main;
  37 }