src/librustc_typeck/check/assoc.rs

   1 // Copyright 2014 The Rust Project Developers. See the COPYRIGHT
   2 // file at the top-level directory of this distribution and at
   3 // http://rust-lang.org/COPYRIGHT.
   4 //
   5 // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
   6 // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
   7 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
   8 // option. This file may not be copied, modified, or distributed
   9 // except according to those terms.
  10
  11 use rustc::infer::InferCtxt;
  12 use rustc::traits::{self, FulfillmentContext, Normalized, MiscObligation,
  13                      SelectionContext, ObligationCause};
  14 use rustc::ty::fold::TypeFoldable;
  15 use syntax::ast;
  16 use syntax::codemap::Span;
  17
  18 //FIXME(@jroesch): Ideally we should be able to drop the fulfillment_cx argument.
  19 pub fn normalize_associated_types_in<'a, 'gcx, 'tcx, T>(
  20     infcx: &InferCtxt<'a, 'gcx, 'tcx>,
  21     fulfillment_cx: &mut FulfillmentContext<'tcx>,
  22     span: Span,
  23     body_id: ast::NodeId,
  24     value: &T) -> T
  25
  26     where T : TypeFoldable<'tcx>
  27 {
  28     debug!("normalize_associated_types_in(value={:?})", value);
  29     let mut selcx = SelectionContext::new(infcx);
  30     let cause = ObligationCause::new(span, body_id, MiscObligation);
  31     let Normalized { value: result, obligations } = traits::normalize(&mut selcx, cause, value);
  32     debug!("normalize_associated_types_in: result={:?} predicates={:?}",
  33            result,
  34            obligations);
  35     for obligation in obligations {
  36         fulfillment_cx.register_predicate_obligation(infcx, obligation);
  37     }
  38     result
  39 }