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#![feature(rustc_attrs)]
// Test for a particular corner case where the evaluation
// cache can get out of date. The problem here is that
// when we cache C, we have observed that it reaches
// to depth 2 (the node for B), but we later realize
// that B itself depends on A (reached depth 0). We
// failed to update the depth for C transitively, which
// resulted in an assertion failure when it was referenced
// from D.
//
// A (reached depth 0)
// E
// B // depth 2 -- reached depth = 0
// C // depth 3 -- reached depth = 2 (should be 0)
// B
// A // depth 0
// D (depth 1)
// C (cache -- reached depth = 2)
struct A {
e: E,
d: C,
}
struct E {
b: B,
}
struct B {
a: Option<Box<A>>,
c: C,
}
struct C {
b: Option<Box<B>>,
}
#[rustc_evaluate_where_clauses]
fn test<X: ?Sized + Send>() {}
fn main() {
test::<A>();
//~^ ERROR evaluate(Binder { value: TraitPredicate(<A as std::marker::Send>, polarity:Positive), bound_vars: [] }) = Ok(EvaluatedToOk)
}
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