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//@ revisions: with_clause without_clause
// Tests that `EvaluatedToOkModuloRegions` from a projection sub-obligation
// is correctly propagated
#![feature(rustc_attrs)]
trait MyTrait {
type Assoc;
}
struct MyStruct;
impl MyTrait for MyStruct {
// Evaluating this projection will result in `EvaluatedToOkModuloRegions`
// (when `with_clause` is enabled)
type Assoc = <Bar as MyTrait>::Assoc;
}
struct Bar;
// The `where` clause on this impl will cause us to produce `EvaluatedToOkModuloRegions`
// when evaluating a projection involving this impl
#[cfg(with_clause)]
impl MyTrait for Bar where for<'b> &'b (): 'b {
type Assoc = bool;
}
// This impl tests that the `EvaluatedToOkModuoRegions` result that we get
// is really due to the `where` clause on the `with_clause` impl
#[cfg(without_clause)]
impl MyTrait for Bar {
type Assoc = bool;
}
// The implementation of `#[rustc_evaluate_where_clauses]` doesn't perform
// normalization, so we need to place the projection predicate behind a normal
// trait predicate
struct Helper {}
trait HelperTrait {}
impl HelperTrait for Helper where <MyStruct as MyTrait>::Assoc: Sized {}
// Evaluating this 'where' clause will (recursively) end up evaluating
// `for<'b> &'b (): 'b`, which will produce `EvaluatedToOkModuloRegions`
#[rustc_evaluate_where_clauses]
fn test(val: MyStruct) where Helper: HelperTrait {
panic!()
}
fn foo(val: MyStruct) {
test(val);
//[with_clause]~^ ERROR evaluate(Binder { value: TraitPredicate(<Helper as HelperTrait>, polarity:Positive), bound_vars: [] }) = Ok(EvaluatedToOkModuloRegions)
//[without_clause]~^^ ERROR evaluate(Binder { value: TraitPredicate(<Helper as HelperTrait>, polarity:Positive), bound_vars: [] }) = Ok(EvaluatedToOk)
}
fn main() {}
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