use rustc::ty::{self, print::Printer, subst::GenericArg, Ty, TyCtxt};
use rustc_data_structures::fx::FxHashMap;
use rustc_data_structures::sync;
-use rustc_error_codes::*;
use rustc_errors::{struct_span_err, Applicability, DiagnosticBuilder};
use rustc_hir as hir;
use rustc_hir::def_id::{CrateNum, DefId};