Simplify a bunch of trait ref obligation creations

Author: oli-obk

compiler/rustc_const_eval/src/transform/check_consts/check.rs

@@ -10,7 +10,7 @@ use rustc_middle::mir::visit::{MutatingUseContext, NonMutatingUseContext, PlaceC
 use rustc_middle::mir::*;
 use rustc_middle::ty::subst::{GenericArgKind, InternalSubsts};
 use rustc_middle::ty::{self, adjustment::PointerCast, Instance, InstanceDef, Ty, TyCtxt};
-use rustc_middle::ty::{Binder, TraitPredicate, TraitRef, TypeVisitable};
+use rustc_middle::ty::{Binder, TraitRef, TypeVisitable};
 use rustc_mir_dataflow::{self, Analysis};
 use rustc_span::{sym, Span, Symbol};
 use rustc_trait_selection::traits::error_reporting::TypeErrCtxtExt as _;
@@ -735,11 +735,8 @@ impl<'tcx> Visitor<'tcx> for Checker<'_, 'tcx> {
                     }
 
                     let trait_ref = TraitRef::from_method(tcx, trait_id, substs);
-                    let poly_trait_pred = Binder::dummy(TraitPredicate {
-                        trait_ref,
-                        constness: ty::BoundConstness::ConstIfConst,
-                        polarity: ty::ImplPolarity::Positive,
-                    });
+                    let poly_trait_pred =
+                        Binder::dummy(trait_ref).with_constness(ty::BoundConstness::ConstIfConst);
                     let obligation =
                         Obligation::new(tcx, ObligationCause::dummy(), param_env, poly_trait_pred);
 
@@ -828,9 +825,7 @@ impl<'tcx> Visitor<'tcx> for Checker<'_, 'tcx> {
                                     tcx,
                                     ObligationCause::dummy_with_span(*fn_span),
                                     param_env,
-                                    tcx.mk_predicate(
-                                        poly_trait_pred.map_bound(ty::PredicateKind::Trait),
-                                    ),
+                                    poly_trait_pred,
                                 );
 
                                 // improve diagnostics by showing what failed. Our requirements are stricter this time

compiler/rustc_const_eval/src/transform/check_consts/ops.rs

@@ -13,10 +13,9 @@ use rustc_middle::mir;
 use rustc_middle::ty::print::with_no_trimmed_paths;
 use rustc_middle::ty::subst::{GenericArgKind, SubstsRef};
 use rustc_middle::ty::{
-    suggest_constraining_type_param, Adt, Closure, DefIdTree, FnDef, FnPtr, Param, TraitPredicate,
-    Ty,
+    suggest_constraining_type_param, Adt, Closure, DefIdTree, FnDef, FnPtr, Param, Ty,
 };
-use rustc_middle::ty::{Binder, BoundConstness, ImplPolarity, TraitRef};
+use rustc_middle::ty::{Binder, TraitRef};
 use rustc_session::parse::feature_err;
 use rustc_span::symbol::sym;
 use rustc_span::{BytePos, Pos, Span, Symbol};
@@ -150,11 +149,7 @@ impl<'tcx> NonConstOp<'tcx> for FnCallNonConst<'tcx> {
                         tcx,
                         ObligationCause::dummy(),
                         param_env,
-                        Binder::dummy(TraitPredicate {
-                            trait_ref,
-                            constness: BoundConstness::NotConst,
-                            polarity: ImplPolarity::Positive,
-                        }),
+                        Binder::dummy(trait_ref),
                     );
 
                     let infcx = tcx.infer_ctxt().build();

compiler/rustc_const_eval/src/transform/check_consts/qualifs.rs

@@ -157,11 +157,8 @@ impl Qualif for NeedsNonConstDrop {
             cx.tcx,
             ObligationCause::dummy_with_span(cx.body.span),
             cx.param_env,
-            ty::Binder::dummy(ty::TraitPredicate {
-                trait_ref: cx.tcx.at(cx.body.span).mk_trait_ref(LangItem::Destruct, [ty]),
-                constness: ty::BoundConstness::ConstIfConst,
-                polarity: ty::ImplPolarity::Positive,
-            }),
+            ty::Binder::dummy(cx.tcx.at(cx.body.span).mk_trait_ref(LangItem::Destruct, [ty]))
+                .with_constness(ty::BoundConstness::ConstIfConst),
         );
 
         let infcx = cx.tcx.infer_ctxt().build();

compiler/rustc_hir_analysis/src/check/wfcheck.rs

@@ -1784,7 +1784,7 @@ fn receiver_is_implemented<'tcx>(
     let tcx = wfcx.tcx();
     let trait_ref = ty::Binder::dummy(tcx.mk_trait_ref(receiver_trait_def_id, [receiver_ty]));
 
-    let obligation = traits::Obligation::new(tcx, cause, wfcx.param_env, trait_ref.without_const());
+    let obligation = traits::Obligation::new(tcx, cause, wfcx.param_env, trait_ref);
 
     if wfcx.infcx.predicate_must_hold_modulo_regions(&obligation) {
         true

compiler/rustc_hir_typeck/src/fn_ctxt/checks.rs

@@ -2149,11 +2149,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                             self.tcx,
                             traits::ObligationCause::dummy(),
                             self.param_env,
-                            ty::Binder::dummy(ty::TraitPredicate {
-                                trait_ref,
-                                constness: ty::BoundConstness::NotConst,
-                                polarity: ty::ImplPolarity::Positive,
-                            }),
+                            ty::Binder::dummy(trait_ref),
                         );
                         match SelectionContext::new(&self).select(&obligation) {
                             Ok(Some(traits::ImplSource::UserDefined(impl_source))) => {

compiler/rustc_hir_typeck/src/method/mod.rs

@@ -348,7 +348,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                     },
                 ),
                 self.param_env,
-                poly_trait_ref.without_const(),
+                poly_trait_ref,
             ),
             substs,
         )

compiler/rustc_trait_selection/src/autoderef.rs

@@ -131,7 +131,7 @@ impl<'a, 'tcx> Autoderef<'a, 'tcx> {
             tcx,
             cause.clone(),
             self.param_env,
-            ty::Binder::dummy(trait_ref).without_const(),
+            ty::Binder::dummy(trait_ref),
         );
         if !self.infcx.predicate_may_hold(&obligation) {
             debug!("overloaded_deref_ty: cannot match obligation");

compiler/rustc_trait_selection/src/traits/object_safety.rs

@@ -723,8 +723,7 @@ fn receiver_is_dispatchable<'tcx>(
     let obligation = {
         let predicate = ty::Binder::dummy(
             tcx.mk_trait_ref(dispatch_from_dyn_did, [receiver_ty, unsized_receiver_ty]),
-        )
-        .without_const();
+        );
 
         Obligation::new(tcx, ObligationCause::dummy(), param_env, predicate)
     };

compiler/rustc_trait_selection/src/traits/select/candidate_assembly.rs

@@ -731,12 +731,8 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
         // <ty as Deref>
         let trait_ref = tcx.mk_trait_ref(tcx.lang_items().deref_trait()?, [ty]);
 
-        let obligation = traits::Obligation::new(
-            tcx,
-            cause.clone(),
-            param_env,
-            ty::Binder::dummy(trait_ref).without_const(),
-        );
+        let obligation =
+            traits::Obligation::new(tcx, cause.clone(), param_env, ty::Binder::dummy(trait_ref));
         if !self.infcx.predicate_may_hold(&obligation) {
             return None;
         }

src/tools/clippy/clippy_lints/src/ptr.rs

@@ -698,9 +698,8 @@ fn matches_preds<'tcx>(
             cx.tcx,
             ObligationCause::dummy(),
             cx.param_env,
-            cx.tcx.mk_predicate(Binder::bind_with_vars(
+            cx.tcx.mk_predicate(Binder::dummy(
                 PredicateKind::Projection(p.with_self_ty(cx.tcx, ty)),
-                List::empty(),
             )),
         )),
         ExistentialPredicate::AutoTrait(p) => infcx