use crate::traits::specialization_graph;
use crate::ty::fast_reject::{self, SimplifiedType, TreatParams};
-use crate::ty::fold::TypeFoldable;
+use crate::ty::visit::TypeVisitable;
use crate::ty::{Ident, Ty, TyCtxt};
use hir::def_id::LOCAL_CRATE;
use rustc_hir as hir;