const fn foo() -> ! { unsafe { std::mem::transmute(()) } //~^ ERROR evaluation of constant value failed //~| WARN the type `!` does not permit zero-initialization [invalid_value] } // Type defined in a submodule, so that it is not "visibly" // uninhabited (which would change interpreter behavior). pub mod empty { #[derive(Clone, Copy)] enum Void {} #[derive(Clone, Copy)] pub struct Empty(Void); } const FOO: [empty::Empty; 3] = [foo(); 3]; const BAR: [empty::Empty; 3] = [unsafe { std::mem::transmute(()) }; 3]; //~^ ERROR evaluation of constant value failed //~| WARN the type `empty::Empty` does not permit zero-initialization fn main() { FOO; BAR; }