-use rustc::hir;
use rustc::infer::canonical::{Canonical, QueryResponse};
use rustc::traits::query::{normalize::NormalizationResult, CanonicalProjectionGoal, NoSolution};
use rustc::traits::{self, ObligationCause, SelectionContext, TraitEngineExt};
use rustc::ty::query::Providers;
use rustc::ty::{ParamEnvAnd, TyCtxt};
+use rustc_hir as hir;
use rustc_span::DUMMY_SP;
use std::sync::atomic::Ordering;