diff options
Diffstat (limited to 'src/test/ui/associated-consts/defaults-not-assumed-pass.rs')
-rw-r--r-- | src/test/ui/associated-consts/defaults-not-assumed-pass.rs | 42 |
1 files changed, 42 insertions, 0 deletions
diff --git a/src/test/ui/associated-consts/defaults-not-assumed-pass.rs b/src/test/ui/associated-consts/defaults-not-assumed-pass.rs new file mode 100644 index 000000000..c08e05c8a --- /dev/null +++ b/src/test/ui/associated-consts/defaults-not-assumed-pass.rs @@ -0,0 +1,42 @@ +// run-pass + +trait Tr { + const A: u8 = 255; + + // This should not be a constant evaluation error (overflow). The value of + // `Self::A` must not be assumed to hold inside the trait. + const B: u8 = Self::A + 1; +} + +// An impl that doesn't override any constant will NOT cause a const eval error +// just because it's defined, but only if the bad constant is used anywhere. +// This matches the behavior without defaults. +impl Tr for () {} + +// An impl that overrides either constant with a suitable value will be fine. +impl Tr for u8 { + const A: u8 = 254; +} + +impl Tr for u16 { + const B: u8 = 0; +} + +impl Tr for u32 { + const A: u8 = 254; + const B: u8 = 0; +} + +fn main() { + assert_eq!(<() as Tr>::A, 255); + //assert_eq!(<() as Tr>::B, 0); // using this is an error + + assert_eq!(<u8 as Tr>::A, 254); + assert_eq!(<u8 as Tr>::B, 255); + + assert_eq!(<u16 as Tr>::A, 255); + assert_eq!(<u16 as Tr>::B, 0); + + assert_eq!(<u32 as Tr>::A, 254); + assert_eq!(<u32 as Tr>::B, 0); +} |