enum MyEnum { Ok(u8), NotOk }
    
    fn main() {
        let value = MyEnum::Ok(42);
        assert!(matches!(value, MyEnum::Ok(_)));
        
        match value {
            MyEnum::Ok(x) => assert_eq!(x, 42),
            MyEnum::NotOk => unreachable!(),
        }
    }

No unsafe to be found. The feature is there, it just has a different keyword than you might be used to -- the same way Haskell and Java both have something called "class" that mean different things.

Rust enums are a form of tagged unions.

Rust unions are plain old unions that are mainly used for C interop. This is why using them requires unsafe code.