use rustc_infer::infer::{self, TyCtxtInferExt};
use rustc_infer::traits::util;
use rustc_middle::ty::error::{ExpectedFound, TypeError};
-use rustc_middle::ty::subst::{InternalSubsts, Subst};
use rustc_middle::ty::util::ExplicitSelf;
+use rustc_middle::ty::InternalSubsts;
use rustc_middle::ty::{
self, AssocItem, DefIdTree, Ty, TypeFoldable, TypeFolder, TypeSuperFoldable, TypeVisitable,
};