src/test/ui/consts/assoc_const_generic_impl.rs

   1 // build-fail
   2
   3 trait ZeroSized: Sized {
   4     const I_AM_ZERO_SIZED: ();
   5     fn requires_zero_size(self);
   6 }
   7
   8 impl<T: Sized> ZeroSized for T {
   9     const I_AM_ZERO_SIZED: ()  = [()][std::mem::size_of::<Self>()]; //~ ERROR evaluation of `<u32 as ZeroSized>::I_AM_ZERO_SIZED` failed
  10     fn requires_zero_size(self) {
  11         let () = Self::I_AM_ZERO_SIZED;
  12         println!("requires_zero_size called");
  13     }
  14 }
  15
  16 fn main() {
  17     ().requires_zero_size();
  18     42_u32.requires_zero_size();
  19 }