Use regular type equating instead of a custom query

2 files changed, 1 insertions, 21 deletions

diff --git a/compiler/rustc_trait_selection/src/traits/misc.rs b/compiler/rustc_trait_selection/src/traits/misc.rs
index da2b004761f..a1094d98276 100644
--- a/compiler/rustc_trait_selection/src/traits/misc.rs
+++ b/compiler/rustc_trait_selection/src/traits/misc.rs
@@ -1,17 +1,14 @@
 //! Miscellaneous type-system utilities that are too small to deserve their own modules.
 
 use crate::regions::InferCtxtRegionExt;
-use crate::traits::{self, ObligationCause, ObligationCtxt};
+use crate::traits::{self, ObligationCause};
 
 use hir::LangItem;
 use rustc_data_structures::fx::FxIndexSet;
 use rustc_hir as hir;
-use rustc_infer::infer::canonical::Canonical;
 use rustc_infer::infer::{RegionResolutionError, TyCtxtInferExt};
-use rustc_infer::traits::query::NoSolution;
 use rustc_infer::{infer::outlives::env::OutlivesEnvironment, traits::FulfillmentError};
 use rustc_middle::ty::{self, AdtDef, Ty, TyCtxt, TypeVisitableExt};
-use rustc_span::DUMMY_SP;
 
 use super::outlives_bounds::InferCtxtExt;
 
@@ -207,19 +204,3 @@ pub fn all_fields_implement_trait<'tcx>(
 
     if infringing.is_empty() { Ok(()) } else { Err(infringing) }
 }
-
-pub fn check_tys_might_be_eq<'tcx>(
-    tcx: TyCtxt<'tcx>,
-    canonical: Canonical<'tcx, ty::ParamEnvAnd<'tcx, (Ty<'tcx>, Ty<'tcx>)>>,
-) -> Result<(), NoSolution> {
-    let (infcx, key, _) = tcx.infer_ctxt().build_with_canonical(DUMMY_SP, &canonical);
-    let (param_env, (ty_a, ty_b)) = key.into_parts();
-    let ocx = ObligationCtxt::new(&infcx);
-
-    let result = ocx.eq(&ObligationCause::dummy(), param_env, ty_a, ty_b);
-    // use `select_where_possible` instead of `select_all_or_error` so that
-    // we don't get errors from obligations being ambiguous.
-    let errors = ocx.select_where_possible();
-
-    if errors.len() > 0 || result.is_err() { Err(NoSolution) } else { Ok(()) }
-}
diff --git a/compiler/rustc_trait_selection/src/traits/mod.rs b/compiler/rustc_trait_selection/src/traits/mod.rs
index 204bb487c86..f6003a25028 100644
--- a/compiler/rustc_trait_selection/src/traits/mod.rs
+++ b/compiler/rustc_trait_selection/src/traits/mod.rs
@@ -551,7 +551,6 @@ pub fn provide(providers: &mut Providers) {
         specialization_graph_of: specialize::specialization_graph_provider,
         specializes: specialize::specializes,
         instantiate_and_check_impossible_predicates,
-        check_tys_might_be_eq: misc::check_tys_might_be_eq,
         is_impossible_associated_item,
         ..*providers
     };