use rustc_middle::mir::interpret::{ErrorHandled, EvalToConstValueResult};
use rustc_middle::traits::select;
use rustc_middle::ty::error::{ExpectedFound, TypeError};
-use rustc_middle::ty::fold::{TypeFoldable, TypeFolder};
+use rustc_middle::ty::fold::{TypeFoldable, TypeFolder, TypeSuperFoldable};
use rustc_middle::ty::relate::RelateResult;
use rustc_middle::ty::subst::{GenericArg, GenericArgKind, InternalSubsts, SubstsRef};
pub use rustc_middle::ty::IntVarValue;