use rustc::infer::InferCtxt;
use rustc::traits::query::outlives_bounds::OutlivesBound;
use rustc::traits::query::{CanonicalTyGoal, Fallible, NoSolution};
+use rustc::traits::wf;
use rustc::traits::FulfillmentContext;
use rustc::traits::{TraitEngine, TraitEngineExt};
use rustc::ty::outlives::Component;
use rustc::ty::query::Providers;
-use rustc::ty::wf;
use rustc::ty::{self, Ty, TyCtxt, TypeFoldable};
use rustc_hir as hir;
use rustc_span::source_map::DUMMY_SP;