use rustc_infer::traits::query::OutlivesBound;
use rustc_infer::traits::TraitEngineExt as _;
use rustc_middle::ty::query::Providers;
-use rustc_middle::ty::{self, Ty, TyCtxt, TypeFoldable};
+use rustc_middle::ty::{self, Ty, TyCtxt, TypeVisitable};
use rustc_span::source_map::DUMMY_SP;
use rustc_trait_selection::infer::InferCtxtBuilderExt;
use rustc_trait_selection::traits::query::{CanonicalTyGoal, Fallible, NoSolution};
// process it next. Because the resulting predicates aren't always
// guaranteed to be a subset of the original type, so we need to store the
// WF args we've computed in a set.
- let mut checked_wf_args = rustc_data_structures::stable_set::FxHashSet::default();
+ let mut checked_wf_args = rustc_data_structures::fx::FxHashSet::default();
let mut wf_args = vec![ty.into()];
let mut implied_bounds = vec![];