Reduce and prevent unnecessary random-access to `List`

Random-access access to `List` when iterating is `O(n^2)` (`O(n)` when
accessing a single element)

* Removed subscript operator, in favor of a more explicit `get`
* Added conversion from `Iterator` to `ConstIterator`
* Remade existing operations into other solutions when applicable

3 files changed, 12 insertions, 11 deletions

diff --git a/core/object/class_db.cpp b/core/object/class_db.cpp
index 876635529c..6b84dfcee9 100644
--- a/core/object/class_db.cpp
+++ b/core/object/class_db.cpp
@@ -425,8 +425,8 @@ uint32_t ClassDB::get_api_hash(APIType p_api) {
 			for (const StringName &F : snames) {
 				MethodInfo &mi = t->signal_map[F];
 				hash = hash_murmur3_one_64(F.hash(), hash);
-				for (int i = 0; i < mi.arguments.size(); i++) {
-					hash = hash_murmur3_one_64(mi.arguments[i].type, hash);
+				for (const PropertyInfo &pi : mi.arguments) {
+					hash = hash_murmur3_one_64(pi.type, hash);
 				}
 			}
 		}
@@ -1856,8 +1856,9 @@ void ClassDB::add_virtual_method(const StringName &p_class, const MethodInfo &p_
 		if (p_arg_names.size() != mi.arguments.size()) {
 			WARN_PRINT("Mismatch argument name count for virtual method: " + String(p_class) + "::" + p_method.name);
 		} else {
-			for (int i = 0; i < p_arg_names.size(); i++) {
-				mi.arguments[i].name = p_arg_names[i];
+			List<PropertyInfo>::Iterator itr = mi.arguments.begin();
+			for (int i = 0; i < p_arg_names.size(); ++itr, ++i) {
+				itr->name = p_arg_names[i];
 			}
 		}
 	}
diff --git a/core/object/method_bind.h b/core/object/method_bind.h
index e97f4abc6a..2f9a2d1679 100644
--- a/core/object/method_bind.h
+++ b/core/object/method_bind.h
@@ -152,7 +152,7 @@ public:
 		if (p_arg < 0) {
 			return _gen_return_type_info();
 		} else if (p_arg < method_info.arguments.size()) {
-			return method_info.arguments[p_arg];
+			return method_info.arguments.get(p_arg);
 		} else {
 			return PropertyInfo(Variant::NIL, "arg_" + itos(p_arg), PROPERTY_HINT_NONE, String(), PROPERTY_USAGE_DEFAULT | PROPERTY_USAGE_NIL_IS_VARIANT);
 		}
@@ -193,10 +193,11 @@ public:
 			Vector<StringName> names;
 			names.resize(method_info.arguments.size());
 #endif
-			for (int i = 0; i < method_info.arguments.size(); i++) {
-				at[i + 1] = method_info.arguments[i].type;
+			int i = 0;
+			for (List<PropertyInfo>::ConstIterator itr = method_info.arguments.begin(); itr != method_info.arguments.end(); ++itr, ++i) {
+				at[i + 1] = itr->type;
 #ifdef DEBUG_METHODS_ENABLED
-				names.write[i] = method_info.arguments[i].name;
+				names.write[i] = itr->name;
 #endif
 			}
 
diff --git a/core/object/object.cpp b/core/object/object.cpp
index b6c8a87a22..ab89f96a0d 100644
--- a/core/object/object.cpp
+++ b/core/object/object.cpp
@@ -1302,9 +1302,8 @@ TypedArray<Dictionary> Object::_get_signal_connection_list(const StringName &p_s
 
 TypedArray<Dictionary> Object::_get_incoming_connections() const {
 	TypedArray<Dictionary> ret;
-	int connections_amount = connections.size();
-	for (int idx_conn = 0; idx_conn < connections_amount; idx_conn++) {
-		ret.push_back(connections[idx_conn]);
+	for (const Object::Connection &connection : connections) {
+		ret.push_back(connection);
 	}
 
 	return ret;