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