use rustc::ty::query::Providers;
use rustc::ty::subst::{InternalSubsts, Subst};
use rustc::ty::{self, ParamEnvAnd, Ty, TyCtxt};
use rustc::ty::query::Providers;
use rustc::ty::subst::{InternalSubsts, Subst};
use rustc::ty::{self, ParamEnvAnd, Ty, TyCtxt};