src/test/ui/issues/issue-47706-trait.stderr

   1 error[E0593]: function is expected to take a single 0-tuple as argument, but it takes 2 distinct arguments
   2   --> $DIR/issue-47706-trait.rs:3:24
   3    |
   4 LL |     fn f(&self, _: ()) {
   5    |     ------------------ takes 2 distinct arguments
   6 LL |         None::<()>.map(Self::f);
   7    |                    --- ^^^^^^^ expected function that takes a single 0-tuple as argument
   8    |                    |
   9    |                    required by a bound introduced by this call
  10    |
  11 note: required by a bound in `Option::<T>::map`
  12   --> $SRC_DIR/core/src/option.rs:LL:COL
  13    |
  14 LL |         F: ~const FnOnce(T) -> U,
  15    |            ^^^^^^^^^^^^^^^^^^^^^ required by this bound in `Option::<T>::map`
  16
  17 error: aborting due to previous error
  18
  19 For more information about this error, try `rustc --explain E0593`.