error[E0053]: method `call` has an incompatible type for trait
  --> $DIR/inline-wrong-abi.rs:7:5
   |
LL |     extern "C" fn call(&self, _: ()) -> T {
   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ expected "rust-call" fn, found "C" fn
   |
   = note: expected signature `extern "rust-call" fn(&Foo<_>, ()) -> _`
              found signature `extern "C" fn(&Foo<_>, ()) -> _`

error: aborting due to 1 previous error

For more information about this error, try `rustc --explain E0053`.