rust/tests/ui/traits/inheritance/repeated-supertrait-ambig.rs

44 lines
1.3 KiB
Rust

// Test a case of a trait which extends the same supertrait twice, but
// with difference type parameters. Test then that when we don't give
// enough information to pick between these, no selection is made. In
// this particular case, the two choices are i64/u64 -- so when we use
// an integer literal, we wind up falling this literal back to i32.
// See also `run-pass/trait-repeated-supertrait.rs`.
trait CompareTo<T> {
fn same_as(&self, t: T) -> bool;
}
trait CompareToInts : CompareTo<i64> + CompareTo<u64> {
}
impl CompareTo<i64> for i64 {
fn same_as(&self, t: i64) -> bool { *self == t }
}
impl CompareTo<u64> for i64 {
fn same_as(&self, t: u64) -> bool { *self == (t as i64) }
}
impl CompareToInts for i64 { }
fn with_obj(c: &dyn CompareToInts) -> bool {
c.same_as(22) //~ ERROR `dyn CompareToInts: CompareTo<i32>` is not satisfied
}
fn with_trait<C:CompareToInts>(c: &C) -> bool {
c.same_as(22) //~ ERROR `C: CompareTo<i32>` is not satisfied
}
fn with_ufcs1<C:CompareToInts>(c: &C) -> bool {
<dyn CompareToInts>::same_as(c, 22) //~ ERROR `dyn CompareToInts: CompareTo<i32>` is not satisfi
}
fn with_ufcs2<C:CompareToInts>(c: &C) -> bool {
CompareTo::same_as(c, 22) //~ ERROR `C: CompareTo<i32>` is not satisfied
}
fn main() {
assert_eq!(22_i64.same_as(22), true); //~ ERROR `i64: CompareTo<i32>` is not satisfied
}