src/test/ui/consts/const_discriminant.rs

   1 // run-pass
   2 #![feature(const_discriminant)]
   3
   4 use std::mem::{discriminant, Discriminant};
   5
   6 fn identity<T>(x: T) -> T { x }
   7
   8 enum Test {
   9     A(u8),
  10     B,
  11     C { a: u8, b: u8 },
  12 }
  13
  14 const TEST_A: Discriminant<Test> = discriminant(&Test::A(5));
  15 const TEST_A_OTHER: Discriminant<Test> = discriminant(&Test::A(17));
  16 const TEST_B: Discriminant<Test> = discriminant(&Test::B);
  17
  18 fn main() {
  19     assert_eq!(TEST_A, TEST_A_OTHER);
  20     assert_eq!(TEST_A, discriminant(identity(&Test::A(17))));
  21     assert_eq!(TEST_B, discriminant(identity(&Test::B)));
  22     assert_ne!(TEST_A, TEST_B);
  23     assert_ne!(TEST_B, discriminant(identity(&Test::C { a: 42, b: 7 })));
  24 }