src/test/ui/consts/const-int-pow-rpass.rs

   1 // run-pass
   2
   3 #![feature(const_int_pow)]
   4 #![feature(wrapping_next_power_of_two)]
   5
   6 const IS_POWER_OF_TWO_A: bool = 0u32.is_power_of_two();
   7 const IS_POWER_OF_TWO_B: bool = 32u32.is_power_of_two();
   8 const IS_POWER_OF_TWO_C: bool = 33u32.is_power_of_two();
   9
  10 const POW: u8 = 3u8.pow(5);
  11
  12 const CHECKED_POW_OK: Option<u8> = 3u8.checked_pow(5);
  13 const CHECKED_POW_OVERFLOW: Option<u8> = 3u8.checked_pow(6);
  14
  15 const WRAPPING_POW: u8 = 3u8.wrapping_pow(6);
  16 const OVERFLOWING_POW: (u8, bool) = 3u8.overflowing_pow(6);
  17 const SATURATING_POW: u8 = 3u8.saturating_pow(6);
  18
  19 const NEXT_POWER_OF_TWO: u32 = 3u32.next_power_of_two();
  20
  21 const CHECKED_NEXT_POWER_OF_TWO_OK: Option<u32> = 3u32.checked_next_power_of_two();
  22 const CHECKED_NEXT_POWER_OF_TWO_OVERFLOW: Option<u32> =
  23     u32::max_value().checked_next_power_of_two();
  24
  25 const WRAPPING_NEXT_POWER_OF_TWO: u32 =
  26     u32::max_value().wrapping_next_power_of_two();
  27
  28 fn main() {
  29     assert!(!IS_POWER_OF_TWO_A);
  30     assert!(IS_POWER_OF_TWO_B);
  31     assert!(!IS_POWER_OF_TWO_C);
  32
  33     assert_eq!(POW, 243);
  34
  35     assert_eq!(CHECKED_POW_OK, Some(243));
  36     assert_eq!(CHECKED_POW_OVERFLOW, None);
  37
  38     assert_eq!(WRAPPING_POW, 217);
  39     assert_eq!(OVERFLOWING_POW, (217, true));
  40     assert_eq!(SATURATING_POW, u8::max_value());
  41
  42     assert_eq!(NEXT_POWER_OF_TWO, 4);
  43
  44     assert_eq!(CHECKED_NEXT_POWER_OF_TWO_OK, Some(4));
  45     assert_eq!(CHECKED_NEXT_POWER_OF_TWO_OVERFLOW, None);
  46
  47     assert_eq!(WRAPPING_NEXT_POWER_OF_TWO, 0);
  48 }