- Incorrect type checking when &[] and [] return optional values.

- Failed to find subscript overloading on optional values.
- Added `&[]` overload to HashMap.

lib/std/collections/hashmap.c3

@@ -182,6 +182,24 @@ fn Value*? HashMap.get_ref(&map, Key key)
 	return NOT_FOUND?;
 }
 
+fn Value* HashMap.get_or_create_ref(&map, Key key) @operator(&[])
+{
+	uint hash = rehash(key.hash());
+	if (map.count)
+	{
+		for (Entry *e = map.table[index_for(hash, map.table.len)]; e != null; e = e.next)
+		{
+			if (e.hash == hash && equals(key, e.key)) return &e.value;
+		}
+	}
+	map.set(key, {});
+	for (Entry *e = map.table[index_for(hash, map.table.len)]; e != null; e = e.next)
+    {
+    	if (e.hash == hash && equals(key, e.key)) return &e.value;
+    }
+	unreachable();
+}
+
 fn Entry*? HashMap.get_entry(&map, Key key)
 {
 	if (!map.count) return NOT_FOUND?;

releasenotes.md

@@ -51,6 +51,8 @@
 - Compiler assert when calling unassigned CT functions #2418.
 - Fixed crash in header generation when exporting functions with const enums (#2384).
 - Fix incorrect panic message when slicing with negative size.
+- Incorrect type checking when &[] and [] return optional values.
+- Failed to find subscript overloading on optional values.
 
 ### Stdlib changes
 - Add `==` to `Pair`, `Triple` and TzDateTime. Add print to `Pair` and `Triple`.
@@ -65,6 +67,7 @@
 - Add Freestanding OS types to runtime `env::` booleans.
 - Added libloaderapi to `std::os::win32`.
 - Added `HashSet.values` and `String.contains_char` #2386
+- Added `&[]` overload to HashMap.
 
 ## 0.7.4 Change list
 

src/compiler/sema_decls.c

@@ -1851,7 +1851,7 @@ static bool sema_analyse_operator_common(SemaContext *context, Decl *method, Typ
 
 Decl *sema_find_untyped_operator(Type *type, OperatorOverload operator_overload, Decl *skipped)
 {
-	type = type->canonical;
+	type = type_no_optional(type)->canonical;
 	assert(operator_overload < OVERLOAD_TYPED_START);
 	if (!type_may_have_sub_elements(type)) return NULL;
 	Decl *def = type->decl;
@@ -2098,7 +2098,7 @@ static inline bool sema_analyse_operator_element_at(SemaContext *context, Decl *
 			RETURN_SEMA_ERROR(rtype, "%s has unknown size and cannot be used as a return type.",
 			                  type_quoted_error_string(rtype->type));
 	}
-	if (method->func_decl.operator == OVERLOAD_ELEMENT_REF && !type_is_pointer(rtype->type))
+	if (method->func_decl.operator == OVERLOAD_ELEMENT_REF && !type_is_pointer(type_no_optional(rtype->type)))
 	{
 		RETURN_SEMA_ERROR(rtype, "The return type must be a pointer, but it is returning %s, did you mean to overload [] instead?",
 		                  type_quoted_error_string(rtype->type));
@@ -2224,7 +2224,7 @@ static inline void sema_get_overload_arguments(Decl *method, Type **value_ref, T
 			*index_ref = method->func_decl.signature.params[1]->type->canonical;
 			return;
 		case OVERLOAD_ELEMENT_REF:
-			*value_ref = type_no_optional(typeget(method->func_decl.signature.rtype)->canonical->pointer);
+			*value_ref = type_no_optional(typeget(method->func_decl.signature.rtype))->canonical->pointer;
 			*index_ref = method->func_decl.signature.params[1]->type->canonical;
 			return;
 		case OVERLOAD_ELEMENT_SET:

src/compiler/sema_expr.c

@@ -11781,7 +11781,7 @@ bool sema_insert_method_call(SemaContext *context, Expr *method_call, Decl *meth
 			.call_expr.is_func_ref = true,
 			.call_expr.is_type_method = true,
 	};
-	Type *type = parent->type->canonical;
+	Type *type = type_no_optional(parent->type)->canonical;
 	Decl *first_param = method_decl->func_decl.signature.params[0];
 	Type *first = first_param->type->canonical;
 	// Deref / addr as needed.
@@ -11796,7 +11796,7 @@ bool sema_insert_method_call(SemaContext *context, Expr *method_call, Decl *meth
 			if (!sema_expr_rewrite_insert_deref(context, parent)) return false;
 		}
 	}
-	ASSERT_SPAN(method_call, parent && parent->type && first == parent->type->canonical);
+	ASSERT_SPAN(method_call, first == type_no_optional(parent->type)->canonical);
 	unit_register_external_symbol(context, method_decl);
 	if (!sema_expr_analyse_general_call(context, method_call, method_decl, parent, false,
 										NULL)) return expr_poison(method_call);

test/unit/stdlib/collections/map.c3

@@ -103,3 +103,16 @@ fn void map_copy()
 	assert(hash_map_copy.len() == hash_map.len());
 
 }
+
+alias Test = HashMap{String, HashMap {String, String}};
+fn void test_ref()
+{
+    Test t;
+    t.init(tmem);
+    (&t["a"]).init(tmem);
+
+    (*&t["a"])["b"] = "ab";
+    test::eq("ab", t["a"]["b"]!!);
+}
+
+