Inputs and output in closure datum are contained in a binder

Author: jackh726

chalk-solve/src/clauses/builtin_traits/fn_family.rs

@@ -87,36 +87,41 @@ pub fn add_fn_family_program_clauses<I: Interner>(
                     _ => false,
                 };
                 if trait_matches {
-                    let substitution = Substitution::from(
-                        interner,
-                        Some(ty.clone().intern(interner).cast(interner))
-                            .into_iter()
-                            .chain(
-                                closure_datum
-                                    .argument_types
-                                    .iter()
-                                    .cloned()
-                                    .map(|ty| ty.cast(interner)),
-                            ),
-                    );
-                    builder.push_fact(TraitRef {
-                        trait_id,
-                        substitution: substitution.clone(),
-                    });
+                    builder.push_binders(
+                        &closure_datum.inputs_and_output,
+                        |builder, inputs_and_output| {
+                            let substitution = Substitution::from(
+                                interner,
+                                Some(ty.clone().intern(interner).cast(interner))
+                                    .into_iter()
+                                    .chain(
+                                        inputs_and_output
+                                            .argument_types
+                                            .iter()
+                                            .cloned()
+                                            .map(|ty| ty.cast(interner)),
+                                    ),
+                            );
+                            builder.push_fact(TraitRef {
+                                trait_id,
+                                substitution: substitution.clone(),
+                            });
 
-                    if let WellKnownTrait::FnOnceTrait = well_known {
-                        let trait_datum = db.trait_datum(trait_id);
-                        let output_id = trait_datum.associated_ty_ids[0];
-                        let alias = AliasTy::Projection(ProjectionTy {
-                            associated_ty_id: output_id,
-                            substitution,
-                        });
-                        let return_type = closure_datum.return_type.clone();
-                        builder.push_fact(Normalize {
-                            alias,
-                            ty: return_type,
-                        });
-                    }
+                            if let WellKnownTrait::FnOnceTrait = well_known {
+                                let trait_datum = db.trait_datum(trait_id);
+                                let output_id = trait_datum.associated_ty_ids[0];
+                                let alias = AliasTy::Projection(ProjectionTy {
+                                    associated_ty_id: output_id,
+                                    substitution,
+                                });
+                                let return_type = inputs_and_output.return_type.clone();
+                                builder.push_fact(Normalize {
+                                    alias,
+                                    ty: return_type,
+                                });
+                            }
+                        },
+                    );
                 }
             }
             _ => {}

chalk-solve/src/rust_ir.rs

@@ -165,11 +165,7 @@ pub struct FnDefDatumBound<I: Interner> {
 }
 
 pub struct ClosureDatum<I: Interner> {
-    /// Types of the closure's arguments
-    pub argument_types: Vec<Ty<I>>,
-
-    /// Return type of the closure
-    pub return_type: Ty<I>,
+    pub inputs_and_output: Binders<FnDefInputsAndOutputDatum<I>>,
 
     pub kind: ClosureKind,
 }