use rustc::ty::{self, Ty, TyCtxt};
use rustc::ty::maps::Providers;
use rustc::traits::{FulfillmentContext, ObligationCause, ObligationCauseCode, Reveal};
use rustc::ty::{self, Ty, TyCtxt};
use rustc::ty::maps::Providers;
use rustc::traits::{FulfillmentContext, ObligationCause, ObligationCauseCode, Reveal};