1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
|
//@ compile-flags: -Znext-solver
#![feature(rustc_attrs)]
// A test showcasing that the solver may need to
// compute a goal which is already in the provisional
// cache.
//
// However, given that `(): BInd` and `(): B` are currently distinct
// goals, this is actually not possible right now.
//
// FIXME(-Znext-solver=coinductive): With the new coinduction approach
// the same goal stack can be both inductive and coinductive, depending
// on why we're proving a specific nested goal. Rewrite this test
// at that point.
#[rustc_coinductive]
trait A {}
#[rustc_coinductive]
trait B {}
trait BInd {}
impl<T: ?Sized + B> BInd for T {}
impl<T: ?Sized + BInd + B> A for T {}
impl<T: ?Sized + BInd> B for T {}
fn impls_a<T: A>() {}
fn main() {
impls_a::<()>();
//~^ ERROR overflow evaluating the requirement `(): A`
}
|
