error[E0601]: `main` function not found in crate `issue_53251`
   |
   = note: consider adding a `main` function to `$DIR/issue-53251.rs`

error[E0087]: too many type parameters provided: expected at most 0 type parameters, found 1 type parameter
  --> $DIR/issue-53251.rs:21:24
   |
LL |                 S::f::<i64>();
   |                        ^^^ expected 0 type parameters
...
LL | impl_add!(a b);
   | --------------- in this macro invocation

error: aborting due to 2 previous errors

Some errors occurred: E0087, E0601.
For more information about an error, try `rustc --explain E0087`.