src/librustc_typeck/outlives/explicit.rs

   1 use rustc::hir::def_id::DefId;
   2 use rustc::ty::{self, OutlivesPredicate, TyCtxt};
   3 use crate::util::nodemap::FxHashMap;
   4
   5 use super::utils::*;
   6
   7 #[derive(Debug)]
   8 pub struct ExplicitPredicatesMap<'tcx> {
   9     map: FxHashMap<DefId, RequiredPredicates<'tcx>>,
  10 }
  11
  12 impl<'tcx> ExplicitPredicatesMap<'tcx> {
  13     pub fn new() -> ExplicitPredicatesMap<'tcx> {
  14         ExplicitPredicatesMap {
  15             map: FxHashMap::default(),
  16         }
  17     }
  18
  19     pub fn explicit_predicates_of(
  20         &mut self,
  21         tcx: TyCtxt<'tcx>,
  22         def_id: DefId,
  23     ) -> &RequiredPredicates<'tcx> {
  24         self.map.entry(def_id).or_insert_with(|| {
  25             let predicates = if def_id.is_local() {
  26                 tcx.explicit_predicates_of(def_id)
  27             } else {
  28                 tcx.predicates_of(def_id)
  29             };
  30             let mut required_predicates = RequiredPredicates::default();
  31
  32             // process predicates and convert to `RequiredPredicates` entry, see below
  33             for (pred, _) in predicates.predicates.iter() {
  34                 match pred {
  35                     ty::Predicate::TypeOutlives(predicate) => {
  36                         let OutlivesPredicate(ref ty, ref reg) = predicate.skip_binder();
  37                         insert_outlives_predicate(tcx, (*ty).into(), reg, &mut required_predicates)
  38                     }
  39
  40                     ty::Predicate::RegionOutlives(predicate) => {
  41                         let OutlivesPredicate(ref reg1, ref reg2) = predicate.skip_binder();
  42                         insert_outlives_predicate(
  43                             tcx,
  44                             (*reg1).into(),
  45                             reg2,
  46                             &mut required_predicates,
  47                         )
  48                     }
  49
  50                     ty::Predicate::Trait(..)
  51                     | ty::Predicate::Projection(..)
  52                     | ty::Predicate::WellFormed(..)
  53                     | ty::Predicate::ObjectSafe(..)
  54                     | ty::Predicate::ClosureKind(..)
  55                     | ty::Predicate::Subtype(..)
  56                     | ty::Predicate::ConstEvaluatable(..) => (),
  57                 }
  58             }
  59
  60             required_predicates
  61         })
  62     }
  63 }