2 #![feature(const_discriminant)]
3 #![feature(bench_black_box)]
6 use std::mem::{discriminant, Discriminant};
7 use std::hint::black_box;
15 const TEST_A: Discriminant<Test> = discriminant(&Test::A(5));
16 const TEST_A_OTHER: Discriminant<Test> = discriminant(&Test::A(17));
17 const TEST_B: Discriminant<Test> = discriminant(&Test::B);
26 const TEST_V: Discriminant<SingleVariant> = discriminant(&SingleVariant::V);
28 pub const TEST_VOID: () = {
29 // This is UB, but CTFE does not check validity so it does not detect this.
30 // This is a regression test for https://github.com/rust-lang/rust/issues/89765.
31 unsafe { std::mem::discriminant(&*(&() as *const () as *const Void)); };
36 assert_eq!(TEST_A, TEST_A_OTHER);
37 assert_eq!(TEST_A, discriminant(black_box(&Test::A(17))));
38 assert_eq!(TEST_B, discriminant(black_box(&Test::B)));
39 assert_ne!(TEST_A, TEST_B);
40 assert_ne!(TEST_B, discriminant(black_box(&Test::C { a: 42, b: 7 })));
42 assert_eq!(TEST_V, discriminant(black_box(&SingleVariant::V)));