feat: Implement where clauses on impls

compiler/noirc_frontend/src/hir/def_collector/dc_mod.rs

@@ -145,12 +145,13 @@
         for trait_impl in impls {
             let trait_name = trait_impl.trait_name.clone();
 
-            let unresolved_functions =
+            let mut unresolved_functions =
                 self.collect_trait_impl_function_overrides(context, &trait_impl, krate);
 
             let module = ModuleId { krate, local_id: self.module_id };
 
-            for (_, func_id, noir_function) in &unresolved_functions.functions {
+            for (_, func_id, noir_function) in &mut unresolved_functions.functions {
+                noir_function.def.where_clause.append(&mut trait_impl.where_clause.clone());
                 context.def_interner.push_function(*func_id, &noir_function.def, module);
             }
 
@@ -382,7 +383,7 @@
                         let modifiers = FunctionModifiers {
                             name: name.to_string(),
                             visibility: crate::FunctionVisibility::Public,
                             // TODO(Maddiaa): Investigate trait implementations with attributes see: https://github.com/noir-lang/noir/issues/2629
                             attributes: crate::token::Attributes::empty(),
                             is_unconstrained: false,
                             contract_function_type: None,
@@ -438,7 +439,7 @@
                         }
                     }
                     TraitItem::Type { name } => {
                         // TODO(nickysn or alexvitkov): implement context.def_interner.push_empty_type_alias and get an id, instead of using TypeAliasId::dummy_id()
                         if let Err((first_def, second_def)) = self.def_collector.def_map.modules
                             [id.0.local_id.0]
                             .declare_type_alias(name.clone(), TypeAliasId::dummy_id())

tooling/nargo_cli/tests/compile_success_empty/impl_with_where_clause/Nargo.toml

@@ -0,0 +1,7 @@
+[package]
+name = "impl_with_where_clause"
+type = "bin"
+authors = [""]
+compiler_version = "0.10.5"
+
+[dependencies]

tooling/nargo_cli/tests/compile_success_empty/impl_with_where_clause/src/main.nr

@@ -0,0 +1,29 @@
+
+fn main() {
+    let array: [Field; 3] = [1, 2, 3];
+    assert(array.eq(array));
+
+    // Ensure this still works if we have to infer the type of the integer literals
+    let array = [1, 2, 3];
+    assert(array.eq(array));
+}
+
+trait Eq {
+    fn eq(self, other: Self) -> bool;
+}
+
+impl<T, N> Eq for [T; N] where T: Eq {
+    fn eq(self, other: Self) -> bool {
+        let mut ret = true;
+        for i in 0 .. self.len() {
+            ret &= self[i].eq(other[i]);
+        }
+        ret
+    }
+}
+
+impl Eq for Field {
+    fn eq(self, other: Field) -> bool {
+        self == other
+    }
+}