From 92299989bd10fd9855b6d77bc2bfabae218d1eea Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?R=C3=A9mi=20Verschelde?= <rverschelde@gmail.com>
Date: Mon, 26 Jul 2021 17:50:35 +0200
Subject: [PATCH] Use Ref<T> references as iterators where relevant

And const when possible.
---
 core/core_bind.cpp                            | 14 ++++-----
 editor/editor_inspector.cpp                   | 10 +++----
 editor/editor_node.cpp                        | 29 +++----------------
 editor/editor_settings.cpp                    |  4 +--
 editor/filesystem_dock.cpp                    |  2 +-
 editor/import/resource_importer_obj.cpp       |  2 +-
 editor/import_defaults_editor.cpp             |  4 +--
 editor/import_dock.cpp                        |  4 +--
 .../plugins/sprite_frames_editor_plugin.cpp   |  2 +-
 editor/plugins/theme_editor_plugin.cpp        |  2 +-
 editor/settings_config_dialog.cpp             |  2 +-
 modules/gdscript/gdscript.cpp                 | 28 +++++++++---------
 modules/mono/csharp_script.cpp                | 10 +++----
 modules/webrtc/webrtc_multiplayer_peer.cpp    | 10 +++----
 modules/websocket/wsl_server.cpp              |  4 +--
 scene/animation/tween.cpp                     |  8 ++---
 scene/main/scene_tree.cpp                     |  8 ++---
 scene/main/viewport.cpp                       |  2 +-
 18 files changed, 62 insertions(+), 83 deletions(-)

diff --git a/core/core_bind.cpp b/core/core_bind.cpp
index 12fca4215ac..9e96d4b0794 100644
--- a/core/core_bind.cpp
+++ b/core/core_bind.cpp
@@ -355,20 +355,20 @@ void _OS::print_all_textures_by_size() {
 		List<Ref<Resource>> rsrc;
 		ResourceCache::get_cached_resources(&rsrc);
 
-		for (Ref<Resource> E : rsrc) {
-			if (!E->is_class("ImageTexture")) {
+		for (Ref<Resource> &res : rsrc) {
+			if (!res->is_class("ImageTexture")) {
 				continue;
 			}
 
-			Size2 size = E->call("get_size");
-			int fmt = E->call("get_format");
+			Size2 size = res->call("get_size");
+			int fmt = res->call("get_format");
 
 			_OSCoreBindImg img;
 			img.size = size;
 			img.fmt = fmt;
-			img.path = E->get_path();
+			img.path = res->get_path();
 			img.vram = Image::get_image_data_size(img.size.width, img.size.height, Image::Format(img.fmt));
-			img.id = E->get_instance_id();
+			img.id = res->get_instance_id();
 			total += img.vram;
 			imgs.push_back(img);
 		}
@@ -387,7 +387,7 @@ void _OS::print_resources_by_type(const Vector<String> &p_types) {
 	List<Ref<Resource>> resources;
 	ResourceCache::get_cached_resources(&resources);
 
-	for (Ref<Resource> r : resources) {
+	for (const Ref<Resource> &r : resources) {
 		bool found = false;
 
 		for (int i = 0; i < p_types.size(); i++) {
diff --git a/editor/editor_inspector.cpp b/editor/editor_inspector.cpp
index cdbe505441e..3db03c02761 100644
--- a/editor/editor_inspector.cpp
+++ b/editor/editor_inspector.cpp
@@ -1648,7 +1648,7 @@ void EditorInspector::update_tree() {
 
 	Color sscolor = get_theme_color(SNAME("prop_subsection"), SNAME("Editor"));
 
-	for (Ref<EditorInspectorPlugin> ped : valid_plugins) {
+	for (Ref<EditorInspectorPlugin> &ped : valid_plugins) {
 		ped->parse_begin(object);
 		_parse_added_editors(main_vbox, ped);
 	}
@@ -1745,7 +1745,7 @@ void EditorInspector::update_tree() {
 				category->set_tooltip(p.name + "::" + (class_descr_cache[type2] == "" ? "" : class_descr_cache[type2]));
 			}
 
-			for (Ref<EditorInspectorPlugin> ped : valid_plugins) {
+			for (Ref<EditorInspectorPlugin> &ped : valid_plugins) {
 				ped->parse_category(object, p.name);
 				_parse_added_editors(main_vbox, ped);
 			}
@@ -1946,7 +1946,7 @@ void EditorInspector::update_tree() {
 			doc_hint = descr;
 		}
 
-		for (Ref<EditorInspectorPlugin> ped : valid_plugins) {
+		for (Ref<EditorInspectorPlugin> &ped : valid_plugins) {
 			bool exclusive = ped->parse_property(object, p.type, p.name, p.hint, p.hint_string, p.usage, wide_editors);
 
 			List<EditorInspectorPlugin::AddedEditor> editors = ped->added_editors; //make a copy, since plugins may be used again in a sub-inspector
@@ -2028,7 +2028,7 @@ void EditorInspector::update_tree() {
 		}
 	}
 
-	for (Ref<EditorInspectorPlugin> ped : valid_plugins) {
+	for (Ref<EditorInspectorPlugin> &ped : valid_plugins) {
 		ped->parse_end();
 		_parse_added_editors(main_vbox, ped);
 	}
@@ -2595,7 +2595,7 @@ void EditorInspector::_update_script_class_properties(const Object &p_object, Li
 	}
 
 	Set<StringName> added;
-	for (Ref<Script> s : classes) {
+	for (const Ref<Script> &s : classes) {
 		String path = s->get_path();
 		String name = EditorNode::get_editor_data().script_class_get_name(path);
 		if (name.is_empty()) {
diff --git a/editor/editor_node.cpp b/editor/editor_node.cpp
index 267854d7eca..46d76a946fa 100644
--- a/editor/editor_node.cpp
+++ b/editor/editor_node.cpp
@@ -797,8 +797,8 @@ void EditorNode::_resources_changed(const Vector<String> &p_resources) {
 	}
 
 	if (changed.size()) {
-		for (Ref<Resource> E : changed) {
-			E->reload_from_file();
+		for (Ref<Resource> &res : changed) {
+			res->reload_from_file();
 		}
 	}
 }
@@ -1551,7 +1551,7 @@ int EditorNode::_save_external_resources() {
 	int saved = 0;
 	List<Ref<Resource>> cached;
 	ResourceCache::get_cached_resources(&cached);
-	for (Ref<Resource> res : cached) {
+	for (const Ref<Resource> &res : cached) {
 		if (!res->get_path().is_resource_file()) {
 			continue;
 		}
@@ -1641,7 +1641,7 @@ void EditorNode::_save_scene(String p_file, int idx) {
 
 	editor_data.save_editor_external_data();
 
-	for (Ref<AnimatedValuesBackup> E : anim_backups) {
+	for (Ref<AnimatedValuesBackup> &E : anim_backups) {
 		E->restore();
 	}
 
@@ -5333,27 +5333,6 @@ void EditorNode::_file_access_close_error_notify(const String &p_str) {
 }
 
 void EditorNode::reload_scene(const String &p_path) {
-	/*
-	 * No longer necessary since scenes now reset and reload their internal resource if needed.
-	//first of all, reload internal textures, materials, meshes, etc. as they might have changed on disk
-
-	List<Ref<Resource>> cached;
-	ResourceCache::get_cached_resources(&cached);
-	List<Ref<Resource>> to_clear; //clear internal resources from previous scene from being used
-	for (Ref<Resource> E : cached) {
-		if (E->get_path().begins_with(p_path + "::")) { //subresources of existing scene
-			to_clear.push_back(E);
-		}
-	}
-
-	//so reload reloads everything, clear subresources of previous scene
-	while (to_clear.front()) {
-		to_clear.front()->get()->set_path("");
-		to_clear.pop_front();
-	}
-
-	*/
-
 	int scene_idx = -1;
 	for (int i = 0; i < editor_data.get_edited_scene_count(); i++) {
 		if (editor_data.get_scene_path(i) == p_path) {
diff --git a/editor/editor_settings.cpp b/editor/editor_settings.cpp
index a52b14643e5..df4469b6fed 100644
--- a/editor/editor_settings.cpp
+++ b/editor/editor_settings.cpp
@@ -1580,7 +1580,7 @@ void EditorSettings::set_builtin_action_override(const String &p_name, const Arr
 			int event_idx = 0;
 
 			// Check equality of each event.
-			for (Ref<InputEvent> E : builtin_events) {
+			for (const Ref<InputEvent> &E : builtin_events) {
 				if (!E->is_match(p_events[event_idx])) {
 					same_as_builtin = false;
 					break;
@@ -1610,7 +1610,7 @@ const Array EditorSettings::get_builtin_action_overrides(const String &p_name) c
 		Array event_array;
 
 		List<Ref<InputEvent>> events_list = AO->get();
-		for (Ref<InputEvent> E : events_list) {
+		for (const Ref<InputEvent> &E : events_list) {
 			event_array.push_back(E);
 		}
 		return event_array;
diff --git a/editor/filesystem_dock.cpp b/editor/filesystem_dock.cpp
index dbbbb03864a..daee61c2ddc 100644
--- a/editor/filesystem_dock.cpp
+++ b/editor/filesystem_dock.cpp
@@ -1237,7 +1237,7 @@ void FileSystemDock::_update_resource_paths_after_move(const Map<String, String>
 	List<Ref<Resource>> cached;
 	ResourceCache::get_cached_resources(&cached);
 
-	for (Ref<Resource> r : cached) {
+	for (Ref<Resource> &r : cached) {
 		String base_path = r->get_path();
 		String extra_path;
 		int sep_pos = r->get_path().find("::");
diff --git a/editor/import/resource_importer_obj.cpp b/editor/import/resource_importer_obj.cpp
index 8b6bd8066f9..34bc0a7d8de 100644
--- a/editor/import/resource_importer_obj.cpp
+++ b/editor/import/resource_importer_obj.cpp
@@ -438,7 +438,7 @@ Node *EditorOBJImporter::import_scene(const String &p_path, uint32_t p_flags, in
 
 	Node3D *scene = memnew(Node3D);
 
-	for (Ref<Mesh> m : meshes) {
+	for (const Ref<Mesh> &m : meshes) {
 		Ref<EditorSceneImporterMesh> mesh;
 		mesh.instantiate();
 		for (int i = 0; i < m->get_surface_count(); i++) {
diff --git a/editor/import_defaults_editor.cpp b/editor/import_defaults_editor.cpp
index 7c06ef45160..25bca1d4f45 100644
--- a/editor/import_defaults_editor.cpp
+++ b/editor/import_defaults_editor.cpp
@@ -106,7 +106,7 @@ void ImportDefaultsEditor::_update_importer() {
 	List<Ref<ResourceImporter>> importer_list;
 	ResourceFormatImporter::get_singleton()->get_importers(&importer_list);
 	Ref<ResourceImporter> importer;
-	for (Ref<ResourceImporter> E : importer_list) {
+	for (const Ref<ResourceImporter> &E : importer_list) {
 		if (E->get_visible_name() == importers->get_item_text(importers->get_selected())) {
 			importer = E;
 			break;
@@ -166,7 +166,7 @@ void ImportDefaultsEditor::clear() {
 	List<Ref<ResourceImporter>> importer_list;
 	ResourceFormatImporter::get_singleton()->get_importers(&importer_list);
 	Vector<String> names;
-	for (Ref<ResourceImporter> E : importer_list) {
+	for (const Ref<ResourceImporter> &E : importer_list) {
 		String vn = E->get_visible_name();
 		names.push_back(vn);
 	}
diff --git a/editor/import_dock.cpp b/editor/import_dock.cpp
index 1f8fefbe6e7..648e60a5543 100644
--- a/editor/import_dock.cpp
+++ b/editor/import_dock.cpp
@@ -111,7 +111,7 @@ void ImportDock::set_edit_path(const String &p_path) {
 	ResourceFormatImporter::get_singleton()->get_importers_for_extension(p_path.get_extension(), &importers);
 	List<Pair<String, String>> importer_names;
 
-	for (Ref<ResourceImporter> E : importers) {
+	for (const Ref<ResourceImporter> &E : importers) {
 		importer_names.push_back(Pair<String, String>(E->get_visible_name(), E->get_importer_name()));
 	}
 
@@ -254,7 +254,7 @@ void ImportDock::set_edit_multiple_paths(const Vector<String> &p_paths) {
 	ResourceFormatImporter::get_singleton()->get_importers_for_extension(p_paths[0].get_extension(), &importers);
 	List<Pair<String, String>> importer_names;
 
-	for (Ref<ResourceImporter> E : importers) {
+	for (const Ref<ResourceImporter> &E : importers) {
 		importer_names.push_back(Pair<String, String>(E->get_visible_name(), E->get_importer_name()));
 	}
 
diff --git a/editor/plugins/sprite_frames_editor_plugin.cpp b/editor/plugins/sprite_frames_editor_plugin.cpp
index a5d0ebbc128..42f7d23da22 100644
--- a/editor/plugins/sprite_frames_editor_plugin.cpp
+++ b/editor/plugins/sprite_frames_editor_plugin.cpp
@@ -365,7 +365,7 @@ void SpriteFramesEditor::_file_load_request(const Vector<String> &p_path, int p_
 
 	int count = 0;
 
-	for (Ref<Texture2D> &E : resources) {
+	for (const Ref<Texture2D> &E : resources) {
 		undo_redo->add_do_method(frames, "add_frame", edited_anim, E, p_at_pos == -1 ? -1 : p_at_pos + count);
 		undo_redo->add_undo_method(frames, "remove_frame", edited_anim, p_at_pos == -1 ? fc : p_at_pos);
 		count++;
diff --git a/editor/plugins/theme_editor_plugin.cpp b/editor/plugins/theme_editor_plugin.cpp
index 6bd901ceada..6bcc65e30cd 100644
--- a/editor/plugins/theme_editor_plugin.cpp
+++ b/editor/plugins/theme_editor_plugin.cpp
@@ -2906,7 +2906,7 @@ void ThemeTypeEditor::_update_stylebox_from_leading() {
 			continue;
 		}
 
-		for (Ref<StyleBox> F : styleboxes) {
+		for (const Ref<StyleBox> &F : styleboxes) {
 			Ref<StyleBox> sb = F;
 			sb->set(E.name, value);
 		}
diff --git a/editor/settings_config_dialog.cpp b/editor/settings_config_dialog.cpp
index aefa8e434e8..b3ec0c96c43 100644
--- a/editor/settings_config_dialog.cpp
+++ b/editor/settings_config_dialog.cpp
@@ -403,7 +403,7 @@ void EditorSettingsDialog::_shortcut_button_pressed(Object *p_item, int p_column
 				List<Ref<InputEvent>> defaults = InputMap::get_singleton()->get_builtins()[current_action];
 
 				// Convert the list to an array, and only keep key events as this is for the editor.
-				for (Ref<InputEvent> k : defaults) {
+				for (const Ref<InputEvent> &k : defaults) {
 					if (k.is_valid()) {
 						events.append(k);
 					}
diff --git a/modules/gdscript/gdscript.cpp b/modules/gdscript/gdscript.cpp
index bcb53508eae..8957b00a1ba 100644
--- a/modules/gdscript/gdscript.cpp
+++ b/modules/gdscript/gdscript.cpp
@@ -1804,10 +1804,10 @@ void GDScriptLanguage::reload_all_scripts() {
 
 	scripts.sort_custom<GDScriptDepSort>(); //update in inheritance dependency order
 
-	for (Ref<GDScript> E : scripts) {
-		print_verbose("GDScript: Reloading: " + E->get_path());
-		E->load_source_code(E->get_path());
-		E->reload(true);
+	for (Ref<GDScript> &script : scripts) {
+		print_verbose("GDScript: Reloading: " + script->get_path());
+		script->load_source_code(script->get_path());
+		script->reload(true);
 	}
 #endif
 }
@@ -1836,21 +1836,21 @@ void GDScriptLanguage::reload_tool_script(const Ref<Script> &p_script, bool p_so
 
 	scripts.sort_custom<GDScriptDepSort>(); //update in inheritance dependency order
 
-	for (Ref<GDScript> E : scripts) {
-		bool reload = E == p_script || to_reload.has(E->get_base());
+	for (Ref<GDScript> &script : scripts) {
+		bool reload = script == p_script || to_reload.has(script->get_base());
 
 		if (!reload) {
 			continue;
 		}
 
-		to_reload.insert(E, Map<ObjectID, List<Pair<StringName, Variant>>>());
+		to_reload.insert(script, Map<ObjectID, List<Pair<StringName, Variant>>>());
 
 		if (!p_soft_reload) {
 			//save state and remove script from instances
-			Map<ObjectID, List<Pair<StringName, Variant>>> &map = to_reload[E];
+			Map<ObjectID, List<Pair<StringName, Variant>>> &map = to_reload[script];
 
-			while (E->instances.front()) {
-				Object *obj = E->instances.front()->get();
+			while (script->instances.front()) {
+				Object *obj = script->instances.front()->get();
 				//save instance info
 				List<Pair<StringName, Variant>> state;
 				if (obj->get_script_instance()) {
@@ -1863,8 +1863,8 @@ void GDScriptLanguage::reload_tool_script(const Ref<Script> &p_script, bool p_so
 //same thing for placeholders
 #ifdef TOOLS_ENABLED
 
-			while (E->placeholders.size()) {
-				Object *obj = E->placeholders.front()->get()->get_owner();
+			while (script->placeholders.size()) {
+				Object *obj = script->placeholders.front()->get()->get_owner();
 
 				//save instance info
 				if (obj->get_script_instance()) {
@@ -1874,13 +1874,13 @@ void GDScriptLanguage::reload_tool_script(const Ref<Script> &p_script, bool p_so
 					obj->set_script(Variant());
 				} else {
 					// no instance found. Let's remove it so we don't loop forever
-					E->placeholders.erase(E->placeholders.front()->get());
+					script->placeholders.erase(script->placeholders.front()->get());
 				}
 			}
 
 #endif
 
-			for (Map<ObjectID, List<Pair<StringName, Variant>>>::Element *F = E->pending_reload_state.front(); F; F = F->next()) {
+			for (Map<ObjectID, List<Pair<StringName, Variant>>>::Element *F = script->pending_reload_state.front(); F; F = F->next()) {
 				map[F->key()] = F->get(); //pending to reload, use this one instead
 			}
 		}
diff --git a/modules/mono/csharp_script.cpp b/modules/mono/csharp_script.cpp
index b52277974f2..9e8b4d38bf6 100644
--- a/modules/mono/csharp_script.cpp
+++ b/modules/mono/csharp_script.cpp
@@ -874,7 +874,7 @@ void CSharpLanguage::reload_assemblies(bool p_soft_reload) {
 
 	// As scripts are going to be reloaded, must proceed without locking here
 
-	for (Ref<CSharpScript> script : scripts) {
+	for (Ref<CSharpScript> &script : scripts) {
 		to_reload.push_back(script);
 
 		if (script->get_path().is_empty()) {
@@ -934,7 +934,7 @@ void CSharpLanguage::reload_assemblies(bool p_soft_reload) {
 	}
 
 	// After the state of all instances is saved, clear scripts and script instances
-	for (Ref<CSharpScript> script : scripts) {
+	for (Ref<CSharpScript> &script : scripts) {
 		while (script->instances.front()) {
 			Object *obj = script->instances.front()->get();
 			obj->set_script(REF()); // Remove script and existing script instances (placeholder are not removed before domain reload)
@@ -947,7 +947,7 @@ void CSharpLanguage::reload_assemblies(bool p_soft_reload) {
 	if (gdmono->reload_scripts_domain() != OK) {
 		// Failed to reload the scripts domain
 		// Make sure to add the scripts back to their owners before returning
-		for (Ref<CSharpScript> scr : to_reload) {
+		for (Ref<CSharpScript> &scr : to_reload) {
 			for (const Map<ObjectID, CSharpScript::StateBackup>::Element *F = scr->pending_reload_state.front(); F; F = F->next()) {
 				Object *obj = ObjectDB::get_instance(F->key());
 
@@ -982,7 +982,7 @@ void CSharpLanguage::reload_assemblies(bool p_soft_reload) {
 
 	List<Ref<CSharpScript>> to_reload_state;
 
-	for (Ref<CSharpScript> script : to_reload) {
+	for (Ref<CSharpScript> &script : to_reload) {
 #ifdef TOOLS_ENABLED
 		script->exports_invalidated = true;
 #endif
@@ -1087,7 +1087,7 @@ void CSharpLanguage::reload_assemblies(bool p_soft_reload) {
 		to_reload_state.push_back(script);
 	}
 
-	for (Ref<CSharpScript> script : to_reload_state) {
+	for (Ref<CSharpScript> &script : to_reload_state) {
 		for (Set<ObjectID>::Element *F = script->pending_reload_instances.front(); F; F = F->next()) {
 			ObjectID obj_id = F->get();
 			Object *obj = ObjectDB::get_instance(obj_id);
diff --git a/modules/webrtc/webrtc_multiplayer_peer.cpp b/modules/webrtc/webrtc_multiplayer_peer.cpp
index 77857255c16..9b08a26aede 100644
--- a/modules/webrtc/webrtc_multiplayer_peer.cpp
+++ b/modules/webrtc/webrtc_multiplayer_peer.cpp
@@ -154,7 +154,7 @@ void WebRTCMultiplayerPeer::_find_next_peer() {
 	}
 	// After last.
 	while (E) {
-		for (Ref<WebRTCDataChannel> F : E->get()->channels) {
+		for (const Ref<WebRTCDataChannel> &F : E->get()->channels) {
 			if (F->get_available_packet_count()) {
 				next_packet_peer = E->key();
 				return;
@@ -165,7 +165,7 @@ void WebRTCMultiplayerPeer::_find_next_peer() {
 	E = peer_map.front();
 	// Before last
 	while (E) {
-		for (Ref<WebRTCDataChannel> F : E->get()->channels) {
+		for (const Ref<WebRTCDataChannel> &F : E->get()->channels) {
 			if (F->get_available_packet_count()) {
 				next_packet_peer = E->key();
 				return;
@@ -213,7 +213,7 @@ int WebRTCMultiplayerPeer::get_unique_id() const {
 
 void WebRTCMultiplayerPeer::_peer_to_dict(Ref<ConnectedPeer> p_connected_peer, Dictionary &r_dict) {
 	Array channels;
-	for (Ref<WebRTCDataChannel> F : p_connected_peer->channels) {
+	for (Ref<WebRTCDataChannel> &F : p_connected_peer->channels) {
 		channels.push_back(F);
 	}
 	r_dict["connection"] = p_connected_peer->connection;
@@ -297,7 +297,7 @@ Error WebRTCMultiplayerPeer::get_packet(const uint8_t **r_buffer, int &r_buffer_
 		_find_next_peer();
 		ERR_FAIL_V(ERR_UNAVAILABLE);
 	}
-	for (Ref<WebRTCDataChannel> E : peer_map[next_packet_peer]->channels) {
+	for (Ref<WebRTCDataChannel> &E : peer_map[next_packet_peer]->channels) {
 		if (E->get_available_packet_count()) {
 			Error err = E->get_packet(r_buffer, r_buffer_size);
 			_find_next_peer();
@@ -357,7 +357,7 @@ int WebRTCMultiplayerPeer::get_available_packet_count() const {
 	}
 	int size = 0;
 	for (Map<int, Ref<ConnectedPeer>>::Element *E = peer_map.front(); E; E = E->next()) {
-		for (Ref<WebRTCDataChannel> F : E->get()->channels) {
+		for (const Ref<WebRTCDataChannel> &F : E->get()->channels) {
 			size += F->get_available_packet_count();
 		}
 	}
diff --git a/modules/websocket/wsl_server.cpp b/modules/websocket/wsl_server.cpp
index 1df001f86e8..c6eb3d44b47 100644
--- a/modules/websocket/wsl_server.cpp
+++ b/modules/websocket/wsl_server.cpp
@@ -196,7 +196,7 @@ void WSLServer::poll() {
 	remove_ids.clear();
 
 	List<Ref<PendingPeer>> remove_peers;
-	for (Ref<PendingPeer> E : _pending) {
+	for (const Ref<PendingPeer> &E : _pending) {
 		String resource_name;
 		Ref<PendingPeer> ppeer = E;
 		Error err = ppeer->do_handshake(_protocols, handshake_timeout, resource_name);
@@ -224,7 +224,7 @@ void WSLServer::poll() {
 		remove_peers.push_back(ppeer);
 		_on_connect(id, ppeer->protocol, resource_name);
 	}
-	for (Ref<PendingPeer> E : remove_peers) {
+	for (const Ref<PendingPeer> &E : remove_peers) {
 		_pending.erase(E);
 	}
 	remove_peers.clear();
diff --git a/scene/animation/tween.cpp b/scene/animation/tween.cpp
index b31c3d57f98..a57e9868772 100644
--- a/scene/animation/tween.cpp
+++ b/scene/animation/tween.cpp
@@ -46,8 +46,8 @@ void Tween::start_tweeners() {
 		ERR_FAIL_MSG("Tween without commands, aborting.");
 	}
 
-	for (Ref<Tweener> E : tweeners.write[current_step]) {
-		E->start();
+	for (Ref<Tweener> &tweener : tweeners.write[current_step]) {
+		tweener->start();
 	}
 }
 
@@ -253,11 +253,11 @@ bool Tween::step(float p_delta) {
 		float step_delta = rem_delta;
 		step_active = false;
 
-		for (Ref<Tweener> E : tweeners.write[current_step]) {
+		for (Ref<Tweener> &tweener : tweeners.write[current_step]) {
 			// Modified inside Tweener.step().
 			float temp_delta = rem_delta;
 			// Turns to true if any Tweener returns true (i.e. is still not finished).
-			step_active = E->step(temp_delta) || step_active;
+			step_active = tweener->step(temp_delta) || step_active;
 			step_delta = MIN(temp_delta, rem_delta);
 		}
 
diff --git a/scene/main/scene_tree.cpp b/scene/main/scene_tree.cpp
index adba7f1a31a..ea4748da79f 100644
--- a/scene/main/scene_tree.cpp
+++ b/scene/main/scene_tree.cpp
@@ -571,8 +571,8 @@ void SceneTree::finalize() {
 	}
 
 	// cleanup timers
-	for (Ref<SceneTreeTimer> E : timers) {
-		E->release_connections();
+	for (Ref<SceneTreeTimer> &timer : timers) {
+		timer->release_connections();
 	}
 	timers.clear();
 }
@@ -1146,8 +1146,8 @@ Array SceneTree::get_processed_tweens() {
 	ret.resize(tweens.size());
 
 	int i = 0;
-	for (Ref<Tween> E : tweens) {
-		ret[i] = E;
+	for (const Ref<Tween> &tween : tweens) {
+		ret[i] = tween;
 		i++;
 	}
 
diff --git a/scene/main/viewport.cpp b/scene/main/viewport.cpp
index 4231072ed93..27e42db1bde 100644
--- a/scene/main/viewport.cpp
+++ b/scene/main/viewport.cpp
@@ -573,7 +573,7 @@ void Viewport::_process_picking() {
 		// if no mouse event exists, create a motion one. This is necessary because objects or camera may have moved.
 		// while this extra event is sent, it is checked if both camera and last object and last ID did not move. If nothing changed, the event is discarded to avoid flooding with unnecessary motion events every frame
 		bool has_mouse_event = false;
-		for (Ref<InputEvent> m : physics_picking_events) {
+		for (const Ref<InputEvent> &m : physics_picking_events) {
 			if (m.is_valid()) {
 				has_mouse_event = true;
 				break;