//@ run-crash //@ compile-flags: -C debug-assertions //@ error-pattern: trying to construct an enum from an invalid value #[allow(dead_code)] #[repr(u32)] enum Foo { A, B, } #[allow(dead_code)] struct Bar { a: u32, b: u32, } fn main() { let _val: Option<(u32, Foo)> = unsafe { std::mem::transmute::<_, Option<(u32, Foo)>>(Bar { a: 3, b: 3 }) }; }