remove questionable calls to commit_if_ok

compiler/rustc_infer/src/infer/at.rs

@@ -285,13 +285,11 @@ pub fn sub<T>(self, define_opaque_types: DefineOpaqueTypes, a: T, b: T) -> Infer
         T: Relate<'tcx>,
     {
         let Trace { at, trace, a_is_expected } = self;
-        at.infcx.commit_if_ok(|_| {
         let mut fields = at.infcx.combine_fields(trace, at.param_env, define_opaque_types);
         fields
             .sub(a_is_expected)
             .relate(a, b)
             .map(move |_| InferOk { value: (), obligations: fields.obligations })
-        })
     }
 
     /// Makes `a == b`; the expectation is set by the call to
@@ -302,13 +300,11 @@ pub fn eq<T>(self, define_opaque_types: DefineOpaqueTypes, a: T, b: T) -> InferR
         T: Relate<'tcx>,
     {
         let Trace { at, trace, a_is_expected } = self;
-        at.infcx.commit_if_ok(|_| {
         let mut fields = at.infcx.combine_fields(trace, at.param_env, define_opaque_types);
         fields
             .equate(a_is_expected)
             .relate(a, b)
             .map(move |_| InferOk { value: (), obligations: fields.obligations })
-        })
     }
 
     #[instrument(skip(self), level = "debug")]
@@ -317,13 +313,11 @@ pub fn lub<T>(self, define_opaque_types: DefineOpaqueTypes, a: T, b: T) -> Infer
         T: Relate<'tcx>,
     {
         let Trace { at, trace, a_is_expected } = self;
-        at.infcx.commit_if_ok(|_| {
         let mut fields = at.infcx.combine_fields(trace, at.param_env, define_opaque_types);
         fields
             .lub(a_is_expected)
             .relate(a, b)
             .map(move |t| InferOk { value: t, obligations: fields.obligations })
-        })
     }
 
     #[instrument(skip(self), level = "debug")]
@@ -332,13 +326,11 @@ pub fn glb<T>(self, define_opaque_types: DefineOpaqueTypes, a: T, b: T) -> Infer
         T: Relate<'tcx>,
     {
         let Trace { at, trace, a_is_expected } = self;
-        at.infcx.commit_if_ok(|_| {
         let mut fields = at.infcx.combine_fields(trace, at.param_env, define_opaque_types);
         fields
             .glb(a_is_expected)
             .relate(a, b)
             .map(move |t| InferOk { value: t, obligations: fields.obligations })
-        })
     }
 }
 

compiler/rustc_infer/src/infer/canonical/query_response.rs

@@ -620,7 +620,6 @@ fn unify_canonical_vars(
         variables1: &OriginalQueryValues<'tcx>,
         variables2: impl Fn(BoundVar) -> GenericArg<'tcx>,
     ) -> InferResult<'tcx, ()> {
-        self.commit_if_ok(|_| {
         let mut obligations = vec![];
         for (index, value1) in variables1.var_values.iter().enumerate() {
             let value2 = variables2(BoundVar::new(index));
@@ -655,7 +654,6 @@ fn unify_canonical_vars(
             }
         }
         Ok(InferOk { value: (), obligations })
-        })
     }
 }
 

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

@@ -192,13 +192,13 @@ fn confirm_projection_candidate(
             &mut obligations,
         );
 
-        obligations.extend(self.infcx.commit_if_ok(|_| {
+        obligations.extend(
             self.infcx
                 .at(&obligation.cause, obligation.param_env)
                 .sup(DefineOpaqueTypes::No, placeholder_trait_predicate, candidate)
                 .map(|InferOk { obligations, .. }| obligations)
-                .map_err(|_| Unimplemented)
-        })?);
+                .map_err(|_| Unimplemented)?,
+        );
 
         // FIXME(compiler-errors): I don't think this is needed.
         if let ty::Alias(ty::Projection, alias_ty) = placeholder_self_ty.kind() {
@@ -532,13 +532,13 @@ fn confirm_object_candidate(
             &mut nested,
         );
 
-        nested.extend(self.infcx.commit_if_ok(|_| {
+        nested.extend(
             self.infcx
                 .at(&obligation.cause, obligation.param_env)
                 .sup(DefineOpaqueTypes::No, obligation_trait_ref, upcast_trait_ref)
                 .map(|InferOk { obligations, .. }| obligations)
-                .map_err(|_| Unimplemented)
-        })?);
+                .map_err(|_| Unimplemented)?,
+        );
 
         // Check supertraits hold. This is so that their associated type bounds
         // will be checked in the code below.

tests/ui/closure-expected-type/expect-infer-var-appearing-twice.stderr

@@ -9,8 +9,8 @@ LL | |
 LL | |     });
    | |______^ expected due to this
    |
-   = note: expected closure signature `fn(_, _) -> _`
-              found closure signature `fn(u32, i32) -> _`
+   = note: expected closure signature `fn(_, u32) -> _`
+              found closure signature `fn(_, i32) -> _`
 note: required by a bound in `with_closure`
   --> $DIR/expect-infer-var-appearing-twice.rs:2:14
    |