use rustc_middle::ty::error::{ExpectedFound, TypeError};
use rustc_middle::ty::relate::{self, Relate, RelateResult, TypeRelation};
use rustc_middle::ty::subst::SubstsRef;
-use rustc_middle::ty::{self, InferConst, ToPredicate, Ty, TyCtxt, TypeFoldable};
+use rustc_middle::ty::{self, InferConst, ToPredicate, Ty, TyCtxt, TypeVisitable};
use rustc_middle::ty::{IntType, UintType};
use rustc_span::{Span, DUMMY_SP};