error[E0308]: intrinsic has wrong type --> $DIR/E0308.rs:14:5 | LL | fn size_of(); //~ ERROR E0308 | ^^^^^^^^^^^^^^^^ expected (), found usize | = note: expected type `extern "rust-intrinsic" fn()` found type `extern "rust-intrinsic" fn() -> usize` error: aborting due to previous error For more information about this error, try `rustc --explain E0308`.