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// run-pass
#![feature(const_discriminant)]
#![feature(bench_black_box)]
#![allow(dead_code)]
use std::mem::{discriminant, Discriminant};
use std::hint::black_box;
enum Test {
A(u8),
B,
C { a: u8, b: u8 },
}
const TEST_A: Discriminant<Test> = discriminant(&Test::A(5));
const TEST_A_OTHER: Discriminant<Test> = discriminant(&Test::A(17));
const TEST_B: Discriminant<Test> = discriminant(&Test::B);
enum Void {}
enum SingleVariant {
V,
Never(Void),
}
const TEST_V: Discriminant<SingleVariant> = discriminant(&SingleVariant::V);
pub const TEST_VOID: () = {
// This is UB, but CTFE does not check validity so it does not detect this.
// This is a regression test for https://github.com/rust-lang/rust/issues/89765.
unsafe { std::mem::discriminant(&*(&() as *const () as *const Void)); };
};
fn main() {
assert_eq!(TEST_A, TEST_A_OTHER);
assert_eq!(TEST_A, discriminant(black_box(&Test::A(17))));
assert_eq!(TEST_B, discriminant(black_box(&Test::B)));
assert_ne!(TEST_A, TEST_B);
assert_ne!(TEST_B, discriminant(black_box(&Test::C { a: 42, b: 7 })));
assert_eq!(TEST_V, discriminant(black_box(&SingleVariant::V)));
}
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