compiler/rustc_infer/src/infer/outlives/mod.rs

   1 //! Various code related to computing outlives relations.
   2
   3 pub mod components;
   4 pub mod env;
   5 pub mod obligations;
   6 pub mod test_type_match;
   7 pub mod verify;
   8
   9 use rustc_middle::traits::query::OutlivesBound;
  10 use rustc_middle::ty;
  11
  12 #[instrument(level = "debug", skip(param_env))]
  13 pub fn explicit_outlives_bounds<'tcx>(
  14     param_env: ty::ParamEnv<'tcx>,
  15 ) -> impl Iterator<Item = OutlivesBound<'tcx>> + 'tcx {
  16     param_env
  17         .caller_bounds()
  18         .into_iter()
  19         .map(ty::Predicate::kind)
  20         .filter_map(ty::Binder::no_bound_vars)
  21         .filter_map(move |kind| match kind {
  22             ty::PredicateKind::Projection(..)
  23             | ty::PredicateKind::Trait(..)
  24             | ty::PredicateKind::Coerce(..)
  25             | ty::PredicateKind::Subtype(..)
  26             | ty::PredicateKind::WellFormed(..)
  27             | ty::PredicateKind::ObjectSafe(..)
  28             | ty::PredicateKind::ClosureKind(..)
  29             | ty::PredicateKind::TypeOutlives(..)
  30             | ty::PredicateKind::ConstEvaluatable(..)
  31             | ty::PredicateKind::ConstEquate(..)
  32             | ty::PredicateKind::TypeWellFormedFromEnv(..) => None,
  33             ty::PredicateKind::RegionOutlives(ty::OutlivesPredicate(r_a, r_b)) => {
  34                 Some(OutlivesBound::RegionSubRegion(r_b, r_a))
  35             }
  36         })
  37 }