error[E0308]: intrinsic has wrong type --> $DIR/E0308.rs:4:5 | LL | fn size_of(); | ^^^^^^^^^^^^^^^^ expected (), found usize | = note: expected fn pointer `extern "rust-intrinsic" fn()` found fn pointer `extern "rust-intrinsic" fn() -> usize` error: aborting due to previous error For more information about this error, try `rustc --explain E0308`.