src/test/ui/enum-discriminant/discriminant_value.rs

   1 // run-pass
   2 #![allow(stable_features)]
   3 #![feature(arbitrary_enum_discriminant, core, core_intrinsics)]
   4
   5 extern crate core;
   6 use core::intrinsics::discriminant_value;
   7
   8 enum CLike1 {
   9     A,
  10     B,
  11     C,
  12     D
  13 }
  14
  15 enum CLike2 {
  16     A = 5,
  17     B = 2,
  18     C = 19,
  19     D
  20 }
  21
  22 #[repr(i8)]
  23 enum CLike3 {
  24     A = 5,
  25     B,
  26     C = -1,
  27     D
  28 }
  29
  30 enum ADT {
  31     First(u32, u32),
  32     Second(u64)
  33 }
  34
  35 enum NullablePointer {
  36     Something(&'static u32),
  37     Nothing
  38 }
  39
  40 static CONST : u32 = 0xBEEF;
  41
  42 #[allow(dead_code)]
  43 #[repr(isize)]
  44 enum Mixed {
  45     Unit = 3,
  46     Tuple(u16) = 2,
  47     Struct {
  48         a: u8,
  49         b: u16,
  50     } = 1,
  51 }
  52
  53 pub fn main() {
  54     assert_eq!(discriminant_value(&CLike1::A), 0);
  55     assert_eq!(discriminant_value(&CLike1::B), 1);
  56     assert_eq!(discriminant_value(&CLike1::C), 2);
  57     assert_eq!(discriminant_value(&CLike1::D), 3);
  58
  59     assert_eq!(discriminant_value(&CLike2::A), 5);
  60     assert_eq!(discriminant_value(&CLike2::B), 2);
  61     assert_eq!(discriminant_value(&CLike2::C), 19);
  62     assert_eq!(discriminant_value(&CLike2::D), 20);
  63
  64     assert_eq!(discriminant_value(&CLike3::A), 5);
  65     assert_eq!(discriminant_value(&CLike3::B), 6);
  66     assert_eq!(discriminant_value(&CLike3::C), -1_i8 as u64);
  67     assert_eq!(discriminant_value(&CLike3::D), 0);
  68
  69     assert_eq!(discriminant_value(&ADT::First(0,0)), 0);
  70     assert_eq!(discriminant_value(&ADT::Second(5)), 1);
  71
  72     assert_eq!(discriminant_value(&NullablePointer::Nothing), 1);
  73     assert_eq!(discriminant_value(&NullablePointer::Something(&CONST)), 0);
  74
  75     assert_eq!(discriminant_value(&10), 0);
  76     assert_eq!(discriminant_value(&"test"), 0);
  77
  78     assert_eq!(3, discriminant_value(&Mixed::Unit));
  79     assert_eq!(2, discriminant_value(&Mixed::Tuple(5)));
  80     assert_eq!(1, discriminant_value(&Mixed::Struct{a: 7, b: 11}));
  81 }