rust/tests/ui/associated-consts/defaults-cyclic-pass.rs
2024-02-16 20:02:50 +00:00

37 lines
691 B
Rust

//@ run-pass
// Cyclic assoc. const defaults don't error unless *used*
trait Tr {
const A: u8 = Self::B;
const B: u8 = Self::A;
}
// This impl is *allowed* unless its assoc. consts are used, matching the
// behavior without defaults.
impl Tr for () {}
// Overriding either constant breaks the cycle
impl Tr for u8 {
const A: u8 = 42;
}
impl Tr for u16 {
const B: u8 = 0;
}
impl Tr for u32 {
const A: u8 = 100;
const B: u8 = 123;
}
fn main() {
assert_eq!(<u8 as Tr>::A, 42);
assert_eq!(<u8 as Tr>::B, 42);
assert_eq!(<u16 as Tr>::A, 0);
assert_eq!(<u16 as Tr>::B, 0);
assert_eq!(<u32 as Tr>::A, 100);
assert_eq!(<u32 as Tr>::B, 123);
}