src/test/ui/logging-only-prints-once.rs

   1 // run-pass
   2 // ignore-windows
   3 // ignore-emscripten no threads support
   4
   5 use std::cell::Cell;
   6 use std::fmt;
   7 use std::thread;
   8
   9 struct Foo(Cell<isize>);
  10
  11 impl fmt::Debug for Foo {
  12     fn fmt(&self, _fmt: &mut fmt::Formatter) -> fmt::Result {
  13         let Foo(ref f) = *self;
  14         assert_eq!(f.get(), 0);
  15         f.set(1);
  16         Ok(())
  17     }
  18 }
  19
  20 pub fn main() {
  21     thread::spawn(move || {
  22         let mut f = Foo(Cell::new(0));
  23         println!("{:?}", f);
  24         let Foo(ref mut f) = f;
  25         assert_eq!(f.get(), 1);
  26     })
  27     .join()
  28     .ok()
  29     .unwrap();
  30 }