Reduce unnecessary COW on Vector by make writing explicit

This commit makes operator[] on Vector const and adds a write proxy to it.  From
now on writes to Vectors need to happen through the .write proxy. So for
instance:

Vector<int> vec;
vec.push_back(10);
std::cout << vec[0] << std::endl;
vec.write[0] = 20;

Failing to use the .write proxy will cause a compilation error.

In addition COWable datatypes can now embed a CowData pointer to their data.
This means that String, CharString, and VMap no longer use or derive from
Vector.

_ALWAYS_INLINE_ and _FORCE_INLINE_ are now equivalent for debug and non-debug
builds. This is a lot faster for Vector in the editor and while running tests.
The reason why this difference used to exist is because force-inlined methods
used to give a bad debugging experience. After extensive testing with modern
compilers this is no longer the case.

8 files changed, 164 insertions, 164 deletions

diff --git a/scene/gui/gradient_edit.cpp b/scene/gui/gradient_edit.cpp
index b5622604e2..749efe8364 100644
--- a/scene/gui/gradient_edit.cpp
+++ b/scene/gui/gradient_edit.cpp
@@ -256,7 +256,7 @@ void GradientEdit::_gui_input(const Ref<InputEvent> &p_event) {
 		if (!valid)
 			return;
 
-		points[grabbed].offset = newofs;
+		points.write[grabbed].offset = newofs;
 
 		points.sort();
 		for (int i = 0; i < points.size(); i++) {
@@ -407,7 +407,7 @@ void GradientEdit::_color_changed(const Color &p_color) {
 
 	if (grabbed == -1)
 		return;
-	points[grabbed].color = p_color;
+	points.write[grabbed].color = p_color;
 	update();
 	emit_signal("ramp_changed");
 }
diff --git a/scene/gui/item_list.cpp b/scene/gui/item_list.cpp
index aa52739b0a..5c79741682 100644
--- a/scene/gui/item_list.cpp
+++ b/scene/gui/item_list.cpp
@@ -72,7 +72,7 @@ void ItemList::set_item_text(int p_idx, const String &p_text) {
 
 	ERR_FAIL_INDEX(p_idx, items.size());
 
-	items[p_idx].text = p_text;
+	items.write[p_idx].text = p_text;
 	update();
 	shape_changed = true;
 }
@@ -85,7 +85,7 @@ String ItemList::get_item_text(int p_idx) const {
 
 void ItemList::set_item_tooltip_enabled(int p_idx, const bool p_enabled) {
 	ERR_FAIL_INDEX(p_idx, items.size());
-	items[p_idx].tooltip_enabled = p_enabled;
+	items.write[p_idx].tooltip_enabled = p_enabled;
 }
 
 bool ItemList::is_item_tooltip_enabled(int p_idx) const {
@@ -97,7 +97,7 @@ void ItemList::set_item_tooltip(int p_idx, const String &p_tooltip) {
 
 	ERR_FAIL_INDEX(p_idx, items.size());
 
-	items[p_idx].tooltip = p_tooltip;
+	items.write[p_idx].tooltip = p_tooltip;
 	update();
 	shape_changed = true;
 }
@@ -112,7 +112,7 @@ void ItemList::set_item_icon(int p_idx, const Ref<Texture> &p_icon) {
 
 	ERR_FAIL_INDEX(p_idx, items.size());
 
-	items[p_idx].icon = p_icon;
+	items.write[p_idx].icon = p_icon;
 	update();
 	shape_changed = true;
 }
@@ -128,7 +128,7 @@ void ItemList::set_item_icon_region(int p_idx, const Rect2 &p_region) {
 
 	ERR_FAIL_INDEX(p_idx, items.size());
 
-	items[p_idx].icon_region = p_region;
+	items.write[p_idx].icon_region = p_region;
 	update();
 	shape_changed = true;
 }
@@ -144,7 +144,7 @@ void ItemList::set_item_icon_modulate(int p_idx, const Color &p_modulate) {
 
 	ERR_FAIL_INDEX(p_idx, items.size());
 
-	items[p_idx].icon_modulate = p_modulate;
+	items.write[p_idx].icon_modulate = p_modulate;
 	update();
 }
 
@@ -159,7 +159,7 @@ void ItemList::set_item_custom_bg_color(int p_idx, const Color &p_custom_bg_colo
 
 	ERR_FAIL_INDEX(p_idx, items.size());
 
-	items[p_idx].custom_bg = p_custom_bg_color;
+	items.write[p_idx].custom_bg = p_custom_bg_color;
 }
 
 Color ItemList::get_item_custom_bg_color(int p_idx) const {
@@ -173,7 +173,7 @@ void ItemList::set_item_custom_fg_color(int p_idx, const Color &p_custom_fg_colo
 
 	ERR_FAIL_INDEX(p_idx, items.size());
 
-	items[p_idx].custom_fg = p_custom_fg_color;
+	items.write[p_idx].custom_fg = p_custom_fg_color;
 }
 
 Color ItemList::get_item_custom_fg_color(int p_idx) const {
@@ -187,7 +187,7 @@ void ItemList::set_item_tag_icon(int p_idx, const Ref<Texture> &p_tag_icon) {
 
 	ERR_FAIL_INDEX(p_idx, items.size());
 
-	items[p_idx].tag_icon = p_tag_icon;
+	items.write[p_idx].tag_icon = p_tag_icon;
 	update();
 	shape_changed = true;
 }
@@ -202,7 +202,7 @@ void ItemList::set_item_selectable(int p_idx, bool p_selectable) {
 
 	ERR_FAIL_INDEX(p_idx, items.size());
 
-	items[p_idx].selectable = p_selectable;
+	items.write[p_idx].selectable = p_selectable;
 }
 
 bool ItemList::is_item_selectable(int p_idx) const {
@@ -215,7 +215,7 @@ void ItemList::set_item_disabled(int p_idx, bool p_disabled) {
 
 	ERR_FAIL_INDEX(p_idx, items.size());
 
-	items[p_idx].disabled = p_disabled;
+	items.write[p_idx].disabled = p_disabled;
 	update();
 }
 
@@ -229,7 +229,7 @@ void ItemList::set_item_metadata(int p_idx, const Variant &p_metadata) {
 
 	ERR_FAIL_INDEX(p_idx, items.size());
 
-	items[p_idx].metadata = p_metadata;
+	items.write[p_idx].metadata = p_metadata;
 	update();
 	shape_changed = true;
 }
@@ -250,7 +250,7 @@ void ItemList::select(int p_idx, bool p_single) {
 		}
 
 		for (int i = 0; i < items.size(); i++) {
-			items[i].selected = p_idx == i;
+			items.write[i].selected = p_idx == i;
 		}
 
 		current = p_idx;
@@ -258,7 +258,7 @@ void ItemList::select(int p_idx, bool p_single) {
 	} else {
 
 		if (items[p_idx].selectable && !items[p_idx].disabled) {
-			items[p_idx].selected = true;
+			items.write[p_idx].selected = true;
 		}
 	}
 	update();
@@ -268,10 +268,10 @@ void ItemList::unselect(int p_idx) {
 	ERR_FAIL_INDEX(p_idx, items.size());
 
 	if (select_mode != SELECT_MULTI) {
-		items[p_idx].selected = false;
+		items.write[p_idx].selected = false;
 		current = -1;
 	} else {
-		items[p_idx].selected = false;
+		items.write[p_idx].selected = false;
 	}
 	update();
 }
@@ -283,7 +283,7 @@ void ItemList::unselect_all() {
 
 	for (int i = 0; i < items.size(); i++) {
 
-		items[i].selected = false;
+		items.write[i].selected = false;
 	}
 	current = -1;
 	update();
@@ -869,8 +869,8 @@ void ItemList::_notification(int p_what) {
 				// elements need to adapt to the selected size
 				minsize.y += vseparation;
 				minsize.x += hseparation;
-				items[i].rect_cache.size = minsize;
-				items[i].min_rect_cache.size = minsize;
+				items.write[i].rect_cache.size = minsize;
+				items.write[i].min_rect_cache.size = minsize;
 			}
 
 			int fit_size = size.x - bg->get_minimum_size().width - mw;
@@ -897,8 +897,8 @@ void ItemList::_notification(int p_what) {
 					}
 
 					if (same_column_width)
-						items[i].rect_cache.size.x = max_column_width;
-					items[i].rect_cache.position = ofs;
+						items.write[i].rect_cache.size.x = max_column_width;
+					items.write[i].rect_cache.position = ofs;
 					max_h = MAX(max_h, items[i].rect_cache.size.y);
 					ofs.x += items[i].rect_cache.size.x + hseparation;
 					col++;
@@ -908,7 +908,7 @@ void ItemList::_notification(int p_what) {
 							separators.push_back(ofs.y + max_h + vseparation / 2);
 
 						for (int j = i; j >= 0 && col > 0; j--, col--) {
-							items[j].rect_cache.size.y = max_h;
+							items.write[j].rect_cache.size.y = max_h;
 						}
 
 						ofs.x = 0;
@@ -919,7 +919,7 @@ void ItemList::_notification(int p_what) {
 				}
 
 				for (int j = items.size() - 1; j >= 0 && col > 0; j--, col--) {
-					items[j].rect_cache.size.y = max_h;
+					items.write[j].rect_cache.size.y = max_h;
 				}
 
 				if (all_fit) {
@@ -1103,8 +1103,8 @@ void ItemList::_notification(int p_what) {
 
 						int cs = j < ss ? font->get_char_size(items[i].text[j], items[i].text[j + 1]).x : 0;
 						if (ofs + cs > max_len || j == ss) {
-							line_limit_cache[line] = j;
-							line_size_cache[line] = ofs;
+							line_limit_cache.write[line] = j;
+							line_size_cache.write[line] = ofs;
 							line++;
 							ofs = 0;
 							if (line >= max_text_lines)
diff --git a/scene/gui/popup_menu.cpp b/scene/gui/popup_menu.cpp
index ebec61ee6d..cd4ece0950 100644
--- a/scene/gui/popup_menu.cpp
+++ b/scene/gui/popup_menu.cpp
@@ -410,7 +410,7 @@ void PopupMenu::_notification(int p_what) {
 		case NOTIFICATION_TRANSLATION_CHANGED: {
 
 			for (int i = 0; i < items.size(); i++) {
-				items[i].xl_text = tr(items[i].text);
+				items.write[i].xl_text = tr(items[i].text);
 			}
 
 			minimum_size_changed();
@@ -524,7 +524,7 @@ void PopupMenu::_notification(int p_what) {
 					font->draw(ci, item_ofs + Point2(0, Math::floor((h - font_h) / 2.0)), text, i == mouse_over ? font_color_hover : font_color_accel);
 				}
 
-				items[i]._ofs_cache = ofs.y;
+				items.write[i]._ofs_cache = ofs.y;
 
 				ofs.y += h;
 			}
@@ -622,7 +622,7 @@ void PopupMenu::add_check_item(const String &p_label, int p_ID, uint32_t p_accel
 void PopupMenu::add_radio_check_item(const String &p_label, int p_ID, uint32_t p_accel) {
 
 	add_check_item(p_label, p_ID, p_accel);
-	items[items.size() - 1].checkable_type = Item::CHECKABLE_TYPE_RADIO_BUTTON;
+	items.write[items.size() - 1].checkable_type = Item::CHECKABLE_TYPE_RADIO_BUTTON;
 	update();
 	minimum_size_changed();
 }
@@ -630,7 +630,7 @@ void PopupMenu::add_radio_check_item(const String &p_label, int p_ID, uint32_t p
 void PopupMenu::add_icon_radio_check_item(const Ref<Texture> &p_icon, const String &p_label, int p_ID, uint32_t p_accel) {
 
 	add_icon_check_item(p_icon, p_label, p_ID, p_accel);
-	items[items.size() - 1].checkable_type = Item::CHECKABLE_TYPE_RADIO_BUTTON;
+	items.write[items.size() - 1].checkable_type = Item::CHECKABLE_TYPE_RADIO_BUTTON;
 	update();
 	minimum_size_changed();
 }
@@ -702,7 +702,7 @@ void PopupMenu::add_check_shortcut(const Ref<ShortCut> &p_shortcut, int p_ID, bo
 void PopupMenu::add_radio_check_shortcut(const Ref<ShortCut> &p_shortcut, int p_ID, bool p_global) {
 
 	add_check_shortcut(p_shortcut, p_ID, p_global);
-	items[items.size() - 1].checkable_type = Item::CHECKABLE_TYPE_RADIO_BUTTON;
+	items.write[items.size() - 1].checkable_type = Item::CHECKABLE_TYPE_RADIO_BUTTON;
 	update();
 	minimum_size_changed();
 }
@@ -724,8 +724,8 @@ void PopupMenu::add_multistate_item(const String &p_label, int p_max_states, int
 void PopupMenu::set_item_text(int p_idx, const String &p_text) {
 
 	ERR_FAIL_INDEX(p_idx, items.size());
-	items[p_idx].text = p_text;
-	items[p_idx].xl_text = tr(p_text);
+	items.write[p_idx].text = p_text;
+	items.write[p_idx].xl_text = tr(p_text);
 
 	update();
 	minimum_size_changed();
@@ -733,7 +733,7 @@ void PopupMenu::set_item_text(int p_idx, const String &p_text) {
 void PopupMenu::set_item_icon(int p_idx, const Ref<Texture> &p_icon) {
 
 	ERR_FAIL_INDEX(p_idx, items.size());
-	items[p_idx].icon = p_icon;
+	items.write[p_idx].icon = p_icon;
 
 	update();
 	minimum_size_changed();
@@ -742,7 +742,7 @@ void PopupMenu::set_item_checked(int p_idx, bool p_checked) {
 
 	ERR_FAIL_INDEX(p_idx, items.size());
 
-	items[p_idx].checked = p_checked;
+	items.write[p_idx].checked = p_checked;
 
 	update();
 	minimum_size_changed();
@@ -750,7 +750,7 @@ void PopupMenu::set_item_checked(int p_idx, bool p_checked) {
 void PopupMenu::set_item_id(int p_idx, int p_ID) {
 
 	ERR_FAIL_INDEX(p_idx, items.size());
-	items[p_idx].ID = p_ID;
+	items.write[p_idx].ID = p_ID;
 
 	update();
 	minimum_size_changed();
@@ -759,7 +759,7 @@ void PopupMenu::set_item_id(int p_idx, int p_ID) {
 void PopupMenu::set_item_accelerator(int p_idx, uint32_t p_accel) {
 
 	ERR_FAIL_INDEX(p_idx, items.size());
-	items[p_idx].accel = p_accel;
+	items.write[p_idx].accel = p_accel;
 
 	update();
 	minimum_size_changed();
@@ -768,7 +768,7 @@ void PopupMenu::set_item_accelerator(int p_idx, uint32_t p_accel) {
 void PopupMenu::set_item_metadata(int p_idx, const Variant &p_meta) {
 
 	ERR_FAIL_INDEX(p_idx, items.size());
-	items[p_idx].metadata = p_meta;
+	items.write[p_idx].metadata = p_meta;
 	update();
 	minimum_size_changed();
 }
@@ -776,7 +776,7 @@ void PopupMenu::set_item_metadata(int p_idx, const Variant &p_meta) {
 void PopupMenu::set_item_disabled(int p_idx, bool p_disabled) {
 
 	ERR_FAIL_INDEX(p_idx, items.size());
-	items[p_idx].disabled = p_disabled;
+	items.write[p_idx].disabled = p_disabled;
 	update();
 	minimum_size_changed();
 }
@@ -784,7 +784,7 @@ void PopupMenu::set_item_disabled(int p_idx, bool p_disabled) {
 void PopupMenu::set_item_submenu(int p_idx, const String &p_submenu) {
 
 	ERR_FAIL_INDEX(p_idx, items.size());
-	items[p_idx].submenu = p_submenu;
+	items.write[p_idx].submenu = p_submenu;
 	update();
 	minimum_size_changed();
 }
@@ -792,7 +792,7 @@ void PopupMenu::set_item_submenu(int p_idx, const String &p_submenu) {
 void PopupMenu::toggle_item_checked(int p_idx) {
 
 	ERR_FAIL_INDEX(p_idx, items.size());
-	items[p_idx].checked = !items[p_idx].checked;
+	items.write[p_idx].checked = !items[p_idx].checked;
 	update();
 	minimum_size_changed();
 }
@@ -886,7 +886,7 @@ int PopupMenu::get_item_state(int p_idx) const {
 void PopupMenu::set_item_as_separator(int p_idx, bool p_separator) {
 
 	ERR_FAIL_INDEX(p_idx, items.size());
-	items[p_idx].separator = p_separator;
+	items.write[p_idx].separator = p_separator;
 	update();
 }
 
@@ -898,21 +898,21 @@ bool PopupMenu::is_item_separator(int p_idx) const {
 void PopupMenu::set_item_as_checkable(int p_idx, bool p_checkable) {
 
 	ERR_FAIL_INDEX(p_idx, items.size());
-	items[p_idx].checkable_type = p_checkable ? Item::CHECKABLE_TYPE_CHECK_BOX : Item::CHECKABLE_TYPE_NONE;
+	items.write[p_idx].checkable_type = p_checkable ? Item::CHECKABLE_TYPE_CHECK_BOX : Item::CHECKABLE_TYPE_NONE;
 	update();
 }
 
 void PopupMenu::set_item_as_radio_checkable(int p_idx, bool p_radio_checkable) {
 
 	ERR_FAIL_INDEX(p_idx, items.size());
-	items[p_idx].checkable_type = p_radio_checkable ? Item::CHECKABLE_TYPE_RADIO_BUTTON : Item::CHECKABLE_TYPE_NONE;
+	items.write[p_idx].checkable_type = p_radio_checkable ? Item::CHECKABLE_TYPE_RADIO_BUTTON : Item::CHECKABLE_TYPE_NONE;
 	update();
 }
 
 void PopupMenu::set_item_tooltip(int p_idx, const String &p_tooltip) {
 
 	ERR_FAIL_INDEX(p_idx, items.size());
-	items[p_idx].tooltip = p_tooltip;
+	items.write[p_idx].tooltip = p_tooltip;
 	update();
 }
 
@@ -921,8 +921,8 @@ void PopupMenu::set_item_shortcut(int p_idx, const Ref<ShortCut> &p_shortcut, bo
 	if (items[p_idx].shortcut.is_valid()) {
 		_unref_shortcut(items[p_idx].shortcut);
 	}
-	items[p_idx].shortcut = p_shortcut;
-	items[p_idx].shortcut_is_global = p_global;
+	items.write[p_idx].shortcut = p_shortcut;
+	items.write[p_idx].shortcut_is_global = p_global;
 
 	if (items[p_idx].shortcut.is_valid()) {
 		_ref_shortcut(items[p_idx].shortcut);
@@ -934,7 +934,7 @@ void PopupMenu::set_item_shortcut(int p_idx, const Ref<ShortCut> &p_shortcut, bo
 void PopupMenu::set_item_h_offset(int p_idx, int p_offset) {
 
 	ERR_FAIL_INDEX(p_idx, items.size());
-	items[p_idx].h_ofs = p_offset;
+	items.write[p_idx].h_ofs = p_offset;
 	update();
 	minimum_size_changed();
 }
@@ -942,14 +942,14 @@ void PopupMenu::set_item_h_offset(int p_idx, int p_offset) {
 void PopupMenu::set_item_multistate(int p_idx, int p_state) {
 
 	ERR_FAIL_INDEX(p_idx, items.size());
-	items[p_idx].state = p_state;
+	items.write[p_idx].state = p_state;
 	update();
 }
 
 void PopupMenu::set_item_shortcut_disabled(int p_idx, bool p_disabled) {
 
 	ERR_FAIL_INDEX(p_idx, items.size());
-	items[p_idx].shortcut_is_disabled = p_disabled;
+	items.write[p_idx].shortcut_is_disabled = p_disabled;
 	update();
 }
 
@@ -960,9 +960,9 @@ void PopupMenu::toggle_item_multistate(int p_idx) {
 		return;
 	}
 
-	++items[p_idx].state;
-	if (items[p_idx].max_states <= items[p_idx].state)
-		items[p_idx].state = 0;
+	++items.write[p_idx].state;
+	if (items.write[p_idx].max_states <= items[p_idx].state)
+		items.write[p_idx].state = 0;
 
 	update();
 }
diff --git a/scene/gui/rich_text_label.cpp b/scene/gui/rich_text_label.cpp
index 857ae8ff4c..a3748bf14c 100644
--- a/scene/gui/rich_text_label.cpp
+++ b/scene/gui/rich_text_label.cpp
@@ -149,7 +149,7 @@ int RichTextLabel::_process_line(ItemFrame *p_frame, const Vector2 &p_ofs, int &
 		if (r_click_item)
 			*r_click_item = NULL;
 	}
-	Line &l = p_frame->lines[p_line];
+	Line &l = p_frame->lines.write[p_line];
 	Item *it = l.from;
 
 	int line_ofs = 0;
@@ -535,9 +535,9 @@ int RichTextLabel::_process_line(ItemFrame *p_frame, const Vector2 &p_ofs, int &
 					int idx = 0;
 					//set minimums to zero
 					for (int i = 0; i < table->columns.size(); i++) {
-						table->columns[i].min_width = 0;
-						table->columns[i].max_width = 0;
-						table->columns[i].width = 0;
+						table->columns.write[i].min_width = 0;
+						table->columns.write[i].max_width = 0;
+						table->columns.write[i].width = 0;
 					}
 					//compute minimum width for each cell
 					const int available_width = p_width - hseparation * (table->columns.size() - 1) - wofs;
@@ -553,8 +553,8 @@ int RichTextLabel::_process_line(ItemFrame *p_frame, const Vector2 &p_ofs, int &
 						for (int i = 0; i < frame->lines.size(); i++) {
 
 							_process_line(frame, Point2(), ly, available_width, i, PROCESS_CACHE, cfont, Color(), font_color_shadow, use_outline, shadow_ofs);
-							table->columns[column].min_width = MAX(table->columns[column].min_width, frame->lines[i].minimum_width);
-							table->columns[column].max_width = MAX(table->columns[column].max_width, frame->lines[i].maximum_width);
+							table->columns.write[column].min_width = MAX(table->columns[column].min_width, frame->lines[i].minimum_width);
+							table->columns.write[column].max_width = MAX(table->columns[column].max_width, frame->lines[i].maximum_width);
 						}
 						idx++;
 					}
@@ -568,16 +568,16 @@ int RichTextLabel::_process_line(ItemFrame *p_frame, const Vector2 &p_ofs, int &
 					for (int i = 0; i < table->columns.size(); i++) {
 						remaining_width -= table->columns[i].min_width;
 						if (table->columns[i].max_width > table->columns[i].min_width)
-							table->columns[i].expand = true;
+							table->columns.write[i].expand = true;
 						if (table->columns[i].expand)
 							total_ratio += table->columns[i].expand_ratio;
 					}
 
 					//assign actual widths
 					for (int i = 0; i < table->columns.size(); i++) {
-						table->columns[i].width = table->columns[i].min_width;
+						table->columns.write[i].width = table->columns[i].min_width;
 						if (table->columns[i].expand)
-							table->columns[i].width += table->columns[i].expand_ratio * remaining_width / total_ratio;
+							table->columns.write[i].width += table->columns[i].expand_ratio * remaining_width / total_ratio;
 						table->total_width += table->columns[i].width + hseparation;
 					}
 
@@ -592,7 +592,7 @@ int RichTextLabel::_process_line(ItemFrame *p_frame, const Vector2 &p_ofs, int &
 							int dif = table->columns[i].width - table->columns[i].max_width;
 							if (dif > 0) {
 								table_need_fit = true;
-								table->columns[i].width = table->columns[i].max_width;
+								table->columns.write[i].width = table->columns[i].max_width;
 								table->total_width -= dif;
 								total_ratio -= table->columns[i].expand_ratio;
 							}
@@ -606,7 +606,7 @@ int RichTextLabel::_process_line(ItemFrame *p_frame, const Vector2 &p_ofs, int &
 									if (dif > 0) {
 										int slice = table->columns[i].expand_ratio * remaining_width / total_ratio;
 										int incr = MIN(dif, slice);
-										table->columns[i].width += incr;
+										table->columns.write[i].width += incr;
 										table->total_width += incr;
 									}
 								}
@@ -626,8 +626,8 @@ int RichTextLabel::_process_line(ItemFrame *p_frame, const Vector2 &p_ofs, int &
 
 							int ly = 0;
 							_process_line(frame, Point2(), ly, table->columns[column].width, i, PROCESS_CACHE, cfont, Color(), font_color_shadow, use_outline, shadow_ofs);
-							frame->lines[i].height_cache = ly; //actual height
-							frame->lines[i].height_accum_cache = ly; //actual height
+							frame->lines.write[i].height_cache = ly; //actual height
+							frame->lines.write[i].height_accum_cache = ly; //actual height
 						}
 						idx++;
 					}
@@ -669,7 +669,7 @@ int RichTextLabel::_process_line(ItemFrame *p_frame, const Vector2 &p_ofs, int &
 
 						yofs += frame->lines[i].height_cache;
 						if (p_mode == PROCESS_CACHE) {
-							frame->lines[i].height_accum_cache = offset.y + draw_ofs.y + frame->lines[i].height_cache;
+							frame->lines.write[i].height_accum_cache = offset.y + draw_ofs.y + frame->lines[i].height_cache;
 						}
 					}
 
@@ -1267,11 +1267,11 @@ void RichTextLabel::_validate_line_caches(ItemFrame *p_frame) {
 
 		int y = 0;
 		_process_line(p_frame, text_rect.get_position(), y, text_rect.get_size().width - scroll_w, i, PROCESS_CACHE, base_font, Color(), font_color_shadow, use_outline, shadow_ofs);
-		p_frame->lines[i].height_cache = y;
-		p_frame->lines[i].height_accum_cache = y;
+		p_frame->lines.write[i].height_cache = y;
+		p_frame->lines.write[i].height_accum_cache = y;
 
 		if (i > 0)
-			p_frame->lines[i].height_accum_cache += p_frame->lines[i - 1].height_accum_cache;
+			p_frame->lines.write[i].height_accum_cache += p_frame->lines[i - 1].height_accum_cache;
 	}
 
 	int total_height = 0;
@@ -1346,7 +1346,7 @@ void RichTextLabel::add_text(const String &p_text) {
 			_add_item(item, false);
 			current_frame->lines.resize(current_frame->lines.size() + 1);
 			if (item->type != ITEM_NEWLINE)
-				current_frame->lines[current_frame->lines.size() - 1].from = item;
+				current_frame->lines.write[current_frame->lines.size() - 1].from = item;
 			_invalidate_current_line(current_frame);
 		}
 
@@ -1369,7 +1369,7 @@ void RichTextLabel::_add_item(Item *p_item, bool p_enter, bool p_ensure_newline)
 	}
 
 	if (current_frame->lines[current_frame->lines.size() - 1].from == NULL) {
-		current_frame->lines[current_frame->lines.size() - 1].from = p_item;
+		current_frame->lines.write[current_frame->lines.size() - 1].from = p_item;
 	}
 	p_item->line = current_frame->lines.size() - 1;
 
@@ -1431,7 +1431,7 @@ bool RichTextLabel::remove_line(const int p_line) {
 	_remove_item(current->subitems[lines], current->subitems[lines]->line, lines);
 
 	if (p_line == 0) {
-		main->lines[0].from = main;
+		main->lines.write[0].from = main;
 	}
 
 	main->first_invalid_line = 0;
@@ -1510,8 +1510,8 @@ void RichTextLabel::push_table(int p_columns) {
 	item->columns.resize(p_columns);
 	item->total_width = 0;
 	for (int i = 0; i < item->columns.size(); i++) {
-		item->columns[i].expand = false;
-		item->columns[i].expand_ratio = 1;
+		item->columns.write[i].expand = false;
+		item->columns.write[i].expand_ratio = 1;
 	}
 	_add_item(item, true, true);
 }
@@ -1521,8 +1521,8 @@ void RichTextLabel::set_table_column_expand(int p_column, bool p_expand, int p_r
 	ERR_FAIL_COND(current->type != ITEM_TABLE);
 	ItemTable *table = static_cast<ItemTable *>(current);
 	ERR_FAIL_INDEX(p_column, table->columns.size());
-	table->columns[p_column].expand = p_expand;
-	table->columns[p_column].expand_ratio = p_ratio;
+	table->columns.write[p_column].expand = p_expand;
+	table->columns.write[p_column].expand_ratio = p_ratio;
 }
 
 void RichTextLabel::push_cell() {
@@ -1536,7 +1536,7 @@ void RichTextLabel::push_cell() {
 	item->cell = true;
 	item->parent_line = item->parent_frame->lines.size() - 1;
 	item->lines.resize(1);
-	item->lines[0].from = NULL;
+	item->lines.write[0].from = NULL;
 	item->first_invalid_line = 0;
 }
 
@@ -2269,7 +2269,7 @@ RichTextLabel::RichTextLabel() {
 	main->index = 0;
 	current = main;
 	main->lines.resize(1);
-	main->lines[0].from = main;
+	main->lines.write[0].from = main;
 	main->first_invalid_line = 0;
 	current_frame = main;
 	tab_size = 4;
diff --git a/scene/gui/tabs.cpp b/scene/gui/tabs.cpp
index b114264de1..50bd1d867c 100644
--- a/scene/gui/tabs.cpp
+++ b/scene/gui/tabs.cpp
@@ -286,7 +286,7 @@ void Tabs::_notification(int p_what) {
 
 			for (int i = 0; i < tabs.size(); i++) {
 
-				tabs[i].ofs_cache = mw;
+				tabs.write[i].ofs_cache = mw;
 				mw += get_tab_width(i);
 			}
 
@@ -314,7 +314,7 @@ void Tabs::_notification(int p_what) {
 				if (i < offset)
 					continue;
 
-				tabs[i].ofs_cache = w;
+				tabs.write[i].ofs_cache = w;
 
 				int lsize = tabs[i].size_cache;
 
@@ -379,7 +379,7 @@ void Tabs::_notification(int p_what) {
 
 					rb->draw(ci, Point2i(w + style->get_margin(MARGIN_LEFT), rb_rect.position.y + style->get_margin(MARGIN_TOP)));
 					w += rb->get_width();
-					tabs[i].rb_rect = rb_rect;
+					tabs.write[i].rb_rect = rb_rect;
 				}
 
 				if (cb_displaypolicy == CLOSE_BUTTON_SHOW_ALWAYS || (cb_displaypolicy == CLOSE_BUTTON_SHOW_ACTIVE_ONLY && i == current)) {
@@ -403,7 +403,7 @@ void Tabs::_notification(int p_what) {
 
 					cb->draw(ci, Point2i(w + style->get_margin(MARGIN_LEFT), cb_rect.position.y + style->get_margin(MARGIN_TOP)));
 					w += cb->get_width();
-					tabs[i].cb_rect = cb_rect;
+					tabs.write[i].cb_rect = cb_rect;
 				}
 
 				w += sb->get_margin(MARGIN_RIGHT);
@@ -471,7 +471,7 @@ bool Tabs::get_offset_buttons_visible() const {
 void Tabs::set_tab_title(int p_tab, const String &p_title) {
 
 	ERR_FAIL_INDEX(p_tab, tabs.size());
-	tabs[p_tab].text = p_title;
+	tabs.write[p_tab].text = p_title;
 	update();
 	minimum_size_changed();
 }
@@ -485,7 +485,7 @@ String Tabs::get_tab_title(int p_tab) const {
 void Tabs::set_tab_icon(int p_tab, const Ref<Texture> &p_icon) {
 
 	ERR_FAIL_INDEX(p_tab, tabs.size());
-	tabs[p_tab].icon = p_icon;
+	tabs.write[p_tab].icon = p_icon;
 	update();
 	minimum_size_changed();
 }
@@ -499,7 +499,7 @@ Ref<Texture> Tabs::get_tab_icon(int p_tab) const {
 void Tabs::set_tab_disabled(int p_tab, bool p_disabled) {
 
 	ERR_FAIL_INDEX(p_tab, tabs.size());
-	tabs[p_tab].disabled = p_disabled;
+	tabs.write[p_tab].disabled = p_disabled;
 	update();
 }
 bool Tabs::get_tab_disabled(int p_tab) const {
@@ -511,7 +511,7 @@ bool Tabs::get_tab_disabled(int p_tab) const {
 void Tabs::set_tab_right_button(int p_tab, const Ref<Texture> &p_right_button) {
 
 	ERR_FAIL_INDEX(p_tab, tabs.size());
-	tabs[p_tab].right_button = p_right_button;
+	tabs.write[p_tab].right_button = p_right_button;
 	_update_cache();
 	update();
 	minimum_size_changed();
@@ -536,9 +536,9 @@ void Tabs::_update_cache() {
 	int size_fixed = 0;
 	int count_resize = 0;
 	for (int i = 0; i < tabs.size(); i++) {
-		tabs[i].ofs_cache = mw;
-		tabs[i].size_cache = get_tab_width(i);
-		tabs[i].size_text = font->get_string_size(tabs[i].text).width;
+		tabs.write[i].ofs_cache = mw;
+		tabs.write[i].size_cache = get_tab_width(i);
+		tabs.write[i].size_text = font->get_string_size(tabs[i].text).width;
 		mw += tabs[i].size_cache;
 		if (tabs[i].size_cache <= min_width || i == current) {
 			size_fixed += tabs[i].size_cache;
@@ -579,9 +579,9 @@ void Tabs::_update_cache() {
 				lsize = m_width;
 			}
 		}
-		tabs[i].ofs_cache = w;
-		tabs[i].size_cache = lsize;
-		tabs[i].size_text = slen;
+		tabs.write[i].ofs_cache = w;
+		tabs.write[i].size_cache = lsize;
+		tabs.write[i].size_text = slen;
 		w += lsize;
 	}
 }
diff --git a/scene/gui/text_edit.cpp b/scene/gui/text_edit.cpp
index cccd1bd197..8926c1ec00 100644
--- a/scene/gui/text_edit.cpp
+++ b/scene/gui/text_edit.cpp
@@ -127,13 +127,13 @@ void TextEdit::Text::_update_line_cache(int p_line) const {
 		w += get_char_width(str[i], str[i + 1], w);
 	}
 
-	text[p_line].width_cache = w;
+	text.write[p_line].width_cache = w;
 
-	text[p_line].wrap_amount_cache = -1;
+	text.write[p_line].wrap_amount_cache = -1;
 
 	//update regions
 
-	text[p_line].region_info.clear();
+	text.write[p_line].region_info.clear();
 
 	for (int i = 0; i < len; i++) {
 
@@ -172,7 +172,7 @@ void TextEdit::Text::_update_line_cache(int p_line) const {
 				ColorRegionInfo cri;
 				cri.end = false;
 				cri.region = j;
-				text[p_line].region_info[i] = cri;
+				text.write[p_line].region_info[i] = cri;
 				i += lr - 1;
 
 				break;
@@ -200,7 +200,7 @@ void TextEdit::Text::_update_line_cache(int p_line) const {
 				ColorRegionInfo cri;
 				cri.end = true;
 				cri.region = j;
-				text[p_line].region_info[i] = cri;
+				text.write[p_line].region_info[i] = cri;
 				i += lr - 1;
 
 				break;
@@ -236,7 +236,7 @@ void TextEdit::Text::set_line_wrap_amount(int p_line, int p_wrap_amount) const {
 
 	ERR_FAIL_INDEX(p_line, text.size());
 
-	text[p_line].wrap_amount_cache = p_wrap_amount;
+	text.write[p_line].wrap_amount_cache = p_wrap_amount;
 }
 
 int TextEdit::Text::get_line_wrap_amount(int p_line) const {
@@ -249,14 +249,14 @@ int TextEdit::Text::get_line_wrap_amount(int p_line) const {
 void TextEdit::Text::clear_width_cache() {
 
 	for (int i = 0; i < text.size(); i++) {
-		text[i].width_cache = -1;
+		text.write[i].width_cache = -1;
 	}
 }
 
 void TextEdit::Text::clear_wrap_cache() {
 
 	for (int i = 0; i < text.size(); i++) {
-		text[i].wrap_amount_cache = -1;
+		text.write[i].wrap_amount_cache = -1;
 	}
 }
 
@@ -281,9 +281,9 @@ void TextEdit::Text::set(int p_line, const String &p_text) {
 
 	ERR_FAIL_INDEX(p_line, text.size());
 
-	text[p_line].width_cache = -1;
-	text[p_line].wrap_amount_cache = -1;
-	text[p_line].data = p_text;
+	text.write[p_line].width_cache = -1;
+	text.write[p_line].wrap_amount_cache = -1;
+	text.write[p_line].data = p_text;
 }
 
 void TextEdit::Text::insert(int p_at, const String &p_text) {
@@ -5729,7 +5729,7 @@ void TextEdit::_update_completion_candidates() {
 
 	for (int i = 0; i < completion_strings.size(); i++) {
 		if (single_quote && completion_strings[i].is_quoted()) {
-			completion_strings[i] = completion_strings[i].unquote().quote("'");
+			completion_strings.write[i] = completion_strings[i].unquote().quote("'");
 		}
 
 		if (s == completion_strings[i]) {
diff --git a/scene/gui/text_edit.h b/scene/gui/text_edit.h
index 34d69bb508..19b5d574c6 100644
--- a/scene/gui/text_edit.h
+++ b/scene/gui/text_edit.h
@@ -101,13 +101,13 @@ public:
 		int get_line_wrap_amount(int p_line) const;
 		const Map<int, ColorRegionInfo> &get_color_region_info(int p_line) const;
 		void set(int p_line, const String &p_text);
-		void set_marked(int p_line, bool p_marked) { text[p_line].marked = p_marked; }
+		void set_marked(int p_line, bool p_marked) { text.write[p_line].marked = p_marked; }
 		bool is_marked(int p_line) const { return text[p_line].marked; }
-		void set_breakpoint(int p_line, bool p_breakpoint) { text[p_line].breakpoint = p_breakpoint; }
+		void set_breakpoint(int p_line, bool p_breakpoint) { text.write[p_line].breakpoint = p_breakpoint; }
 		bool is_breakpoint(int p_line) const { return text[p_line].breakpoint; }
-		void set_hidden(int p_line, bool p_hidden) { text[p_line].hidden = p_hidden; }
+		void set_hidden(int p_line, bool p_hidden) { text.write[p_line].hidden = p_hidden; }
 		bool is_hidden(int p_line) const { return text[p_line].hidden; }
-		void set_safe(int p_line, bool p_safe) { text[p_line].safe = p_safe; }
+		void set_safe(int p_line, bool p_safe) { text.write[p_line].safe = p_safe; }
 		bool is_safe(int p_line) const { return text[p_line].safe; }
 		void insert(int p_at, const String &p_text);
 		void remove(int p_at);
diff --git a/scene/gui/tree.cpp b/scene/gui/tree.cpp
index 6ab1bf3d58..6f09488b64 100644
--- a/scene/gui/tree.cpp
+++ b/scene/gui/tree.cpp
@@ -121,7 +121,7 @@ void TreeItem::_cell_deselected(int p_cell) {
 void TreeItem::set_cell_mode(int p_column, TreeCellMode p_mode) {
 
 	ERR_FAIL_INDEX(p_column, cells.size());
-	Cell &c = cells[p_column];
+	Cell &c = cells.write[p_column];
 	c.mode = p_mode;
 	c.min = 0;
 	c.max = 100;
@@ -144,7 +144,7 @@ TreeItem::TreeCellMode TreeItem::get_cell_mode(int p_column) const {
 void TreeItem::set_checked(int p_column, bool p_checked) {
 
 	ERR_FAIL_INDEX(p_column, cells.size());
-	cells[p_column].checked = p_checked;
+	cells.write[p_column].checked = p_checked;
 	_changed_notify(p_column);
 }
 
@@ -157,22 +157,22 @@ bool TreeItem::is_checked(int p_column) const {
 void TreeItem::set_text(int p_column, String p_text) {
 
 	ERR_FAIL_INDEX(p_column, cells.size());
-	cells[p_column].text = p_text;
+	cells.write[p_column].text = p_text;
 
 	if (cells[p_column].mode == TreeItem::CELL_MODE_RANGE || cells[p_column].mode == TreeItem::CELL_MODE_RANGE_EXPRESSION) {
 
 		Vector<String> strings = p_text.split(",");
-		cells[p_column].min = INT_MAX;
-		cells[p_column].max = INT_MIN;
+		cells.write[p_column].min = INT_MAX;
+		cells.write[p_column].max = INT_MIN;
 		for (int i = 0; i < strings.size(); i++) {
 			int value = i;
 			if (!strings[i].get_slicec(':', 1).empty()) {
 				value = strings[i].get_slicec(':', 1).to_int();
 			}
-			cells[p_column].min = MIN(cells[p_column].min, value);
-			cells[p_column].max = MAX(cells[p_column].max, value);
+			cells.write[p_column].min = MIN(cells[p_column].min, value);
+			cells.write[p_column].max = MAX(cells[p_column].max, value);
 		}
-		cells[p_column].step = 0;
+		cells.write[p_column].step = 0;
 	}
 	_changed_notify(p_column);
 }
@@ -186,7 +186,7 @@ String TreeItem::get_text(int p_column) const {
 void TreeItem::set_suffix(int p_column, String p_suffix) {
 
 	ERR_FAIL_INDEX(p_column, cells.size());
-	cells[p_column].suffix = p_suffix;
+	cells.write[p_column].suffix = p_suffix;
 
 	_changed_notify(p_column);
 }
@@ -200,7 +200,7 @@ String TreeItem::get_suffix(int p_column) const {
 void TreeItem::set_icon(int p_column, const Ref<Texture> &p_icon) {
 
 	ERR_FAIL_INDEX(p_column, cells.size());
-	cells[p_column].icon = p_icon;
+	cells.write[p_column].icon = p_icon;
 	_changed_notify(p_column);
 }
 
@@ -213,7 +213,7 @@ Ref<Texture> TreeItem::get_icon(int p_column) const {
 void TreeItem::set_icon_region(int p_column, const Rect2 &p_icon_region) {
 
 	ERR_FAIL_INDEX(p_column, cells.size());
-	cells[p_column].icon_region = p_icon_region;
+	cells.write[p_column].icon_region = p_icon_region;
 	_changed_notify(p_column);
 }
 
@@ -226,7 +226,7 @@ Rect2 TreeItem::get_icon_region(int p_column) const {
 void TreeItem::set_icon_color(int p_column, const Color &p_icon_color) {
 
 	ERR_FAIL_INDEX(p_column, cells.size());
-	cells[p_column].icon_color = p_icon_color;
+	cells.write[p_column].icon_color = p_icon_color;
 	_changed_notify(p_column);
 }
 
@@ -239,7 +239,7 @@ Color TreeItem::get_icon_color(int p_column) const {
 void TreeItem::set_icon_max_width(int p_column, int p_max) {
 
 	ERR_FAIL_INDEX(p_column, cells.size());
-	cells[p_column].icon_max_w = p_max;
+	cells.write[p_column].icon_max_w = p_max;
 	_changed_notify(p_column);
 }
 
@@ -260,7 +260,7 @@ void TreeItem::set_range(int p_column, double p_value) {
 	if (p_value > cells[p_column].max)
 		p_value = cells[p_column].max;
 
-	cells[p_column].val = p_value;
+	cells.write[p_column].val = p_value;
 	_changed_notify(p_column);
 }
 
@@ -278,10 +278,10 @@ bool TreeItem::is_range_exponential(int p_column) const {
 void TreeItem::set_range_config(int p_column, double p_min, double p_max, double p_step, bool p_exp) {
 
 	ERR_FAIL_INDEX(p_column, cells.size());
-	cells[p_column].min = p_min;
-	cells[p_column].max = p_max;
-	cells[p_column].step = p_step;
-	cells[p_column].expr = p_exp;
+	cells.write[p_column].min = p_min;
+	cells.write[p_column].max = p_max;
+	cells.write[p_column].step = p_step;
+	cells.write[p_column].expr = p_exp;
 	_changed_notify(p_column);
 }
 
@@ -296,7 +296,7 @@ void TreeItem::get_range_config(int p_column, double &r_min, double &r_max, doub
 void TreeItem::set_metadata(int p_column, const Variant &p_meta) {
 
 	ERR_FAIL_INDEX(p_column, cells.size());
-	cells[p_column].meta = p_meta;
+	cells.write[p_column].meta = p_meta;
 }
 
 Variant TreeItem::get_metadata(int p_column) const {
@@ -311,8 +311,8 @@ void TreeItem::set_custom_draw(int p_column, Object *p_object, const StringName
 	ERR_FAIL_INDEX(p_column, cells.size());
 	ERR_FAIL_NULL(p_object);
 
-	cells[p_column].custom_draw_obj = p_object->get_instance_id();
-	cells[p_column].custom_draw_callback = p_callback;
+	cells.write[p_column].custom_draw_obj = p_object->get_instance_id();
+	cells.write[p_column].custom_draw_callback = p_callback;
 }
 
 void TreeItem::set_collapsed(bool p_collapsed) {
@@ -467,7 +467,7 @@ void TreeItem::remove_child(TreeItem *p_item) {
 void TreeItem::set_selectable(int p_column, bool p_selectable) {
 
 	ERR_FAIL_INDEX(p_column, cells.size());
-	cells[p_column].selectable = p_selectable;
+	cells.write[p_column].selectable = p_selectable;
 }
 
 bool TreeItem::is_selectable(int p_column) const {
@@ -517,7 +517,7 @@ void TreeItem::add_button(int p_column, const Ref<Texture> &p_button, int p_id,
 	button.id = p_id;
 	button.disabled = p_disabled;
 	button.tooltip = p_tooltip;
-	cells[p_column].buttons.push_back(button);
+	cells.write[p_column].buttons.push_back(button);
 	_changed_notify(p_column);
 }
 
@@ -540,7 +540,7 @@ void TreeItem::erase_button(int p_column, int p_idx) {
 
 	ERR_FAIL_INDEX(p_column, cells.size());
 	ERR_FAIL_INDEX(p_idx, cells[p_column].buttons.size());
-	cells[p_column].buttons.remove(p_idx);
+	cells.write[p_column].buttons.remove(p_idx);
 	_changed_notify(p_column);
 }
 
@@ -568,7 +568,7 @@ void TreeItem::set_button(int p_column, int p_idx, const Ref<Texture> &p_button)
 	ERR_FAIL_COND(p_button.is_null());
 	ERR_FAIL_INDEX(p_column, cells.size());
 	ERR_FAIL_INDEX(p_idx, cells[p_column].buttons.size());
-	cells[p_column].buttons[p_idx].texture = p_button;
+	cells.write[p_column].buttons.write[p_idx].texture = p_button;
 	_changed_notify(p_column);
 }
 
@@ -576,14 +576,14 @@ void TreeItem::set_button_color(int p_column, int p_idx, const Color &p_color) {
 
 	ERR_FAIL_INDEX(p_column, cells.size());
 	ERR_FAIL_INDEX(p_idx, cells[p_column].buttons.size());
-	cells[p_column].buttons[p_idx].color = p_color;
+	cells.write[p_column].buttons.write[p_idx].color = p_color;
 	_changed_notify(p_column);
 }
 
 void TreeItem::set_editable(int p_column, bool p_editable) {
 
 	ERR_FAIL_INDEX(p_column, cells.size());
-	cells[p_column].editable = p_editable;
+	cells.write[p_column].editable = p_editable;
 	_changed_notify(p_column);
 }
 
@@ -596,8 +596,8 @@ bool TreeItem::is_editable(int p_column) {
 void TreeItem::set_custom_color(int p_column, const Color &p_color) {
 
 	ERR_FAIL_INDEX(p_column, cells.size());
-	cells[p_column].custom_color = true;
-	cells[p_column].color = p_color;
+	cells.write[p_column].custom_color = true;
+	cells.write[p_column].color = p_color;
 	_changed_notify(p_column);
 }
 Color TreeItem::get_custom_color(int p_column) const {
@@ -610,15 +610,15 @@ Color TreeItem::get_custom_color(int p_column) const {
 void TreeItem::clear_custom_color(int p_column) {
 
 	ERR_FAIL_INDEX(p_column, cells.size());
-	cells[p_column].custom_color = false;
-	cells[p_column].color = Color();
+	cells.write[p_column].custom_color = false;
+	cells.write[p_column].color = Color();
 	_changed_notify(p_column);
 }
 
 void TreeItem::set_tooltip(int p_column, const String &p_tooltip) {
 
 	ERR_FAIL_INDEX(p_column, cells.size());
-	cells[p_column].tooltip = p_tooltip;
+	cells.write[p_column].tooltip = p_tooltip;
 }
 
 String TreeItem::get_tooltip(int p_column) const {
@@ -630,17 +630,17 @@ String TreeItem::get_tooltip(int p_column) const {
 void TreeItem::set_custom_bg_color(int p_column, const Color &p_color, bool p_bg_outline) {
 
 	ERR_FAIL_INDEX(p_column, cells.size());
-	cells[p_column].custom_bg_color = true;
-	cells[p_column].custom_bg_outline = p_bg_outline;
-	cells[p_column].bg_color = p_color;
+	cells.write[p_column].custom_bg_color = true;
+	cells.write[p_column].custom_bg_outline = p_bg_outline;
+	cells.write[p_column].bg_color = p_color;
 	_changed_notify(p_column);
 }
 
 void TreeItem::clear_custom_bg_color(int p_column) {
 
 	ERR_FAIL_INDEX(p_column, cells.size());
-	cells[p_column].custom_bg_color = false;
-	cells[p_column].bg_color = Color();
+	cells.write[p_column].custom_bg_color = false;
+	cells.write[p_column].bg_color = Color();
 	_changed_notify(p_column);
 }
 
@@ -655,7 +655,7 @@ Color TreeItem::get_custom_bg_color(int p_column) const {
 void TreeItem::set_custom_as_button(int p_column, bool p_button) {
 
 	ERR_FAIL_INDEX(p_column, cells.size());
-	cells[p_column].custom_button = p_button;
+	cells.write[p_column].custom_button = p_button;
 }
 
 bool TreeItem::is_custom_set_as_button(int p_column) const {
@@ -666,7 +666,7 @@ bool TreeItem::is_custom_set_as_button(int p_column) const {
 
 void TreeItem::set_text_align(int p_column, TextAlign p_align) {
 	ERR_FAIL_INDEX(p_column, cells.size());
-	cells[p_column].text_align = p_align;
+	cells.write[p_column].text_align = p_align;
 	_changed_notify(p_column);
 }
 
@@ -678,7 +678,7 @@ TreeItem::TextAlign TreeItem::get_text_align(int p_column) const {
 void TreeItem::set_expand_right(int p_column, bool p_enable) {
 
 	ERR_FAIL_INDEX(p_column, cells.size());
-	cells[p_column].expand_right = p_enable;
+	cells.write[p_column].expand_right = p_enable;
 	_changed_notify(p_column);
 }
 
@@ -1486,7 +1486,7 @@ int Tree::_count_selected_items(TreeItem *p_from) const {
 }
 void Tree::select_single_item(TreeItem *p_selected, TreeItem *p_current, int p_col, TreeItem *p_prev, bool *r_in_range, bool p_force_deselect) {
 
-	TreeItem::Cell &selected_cell = p_selected->cells[p_col];
+	TreeItem::Cell &selected_cell = p_selected->cells.write[p_col];
 
 	bool switched = false;
 	if (r_in_range && !*r_in_range && (p_current == p_selected || p_current == p_prev)) {
@@ -1498,7 +1498,7 @@ void Tree::select_single_item(TreeItem *p_selected, TreeItem *p_current, int p_c
 
 	for (int i = 0; i < columns.size(); i++) {
 
-		TreeItem::Cell &c = p_current->cells[i];
+		TreeItem::Cell &c = p_current->cells.write[i];
 
 		if (!c.selectable)
 			continue;
@@ -1689,7 +1689,7 @@ int Tree::propagate_mouse_event(const Point2i &p_pos, int x_ofs, int y_ofs, bool
 			return -1; //collapse/uncollapse because nothing can be done with item
 		}
 
-		TreeItem::Cell &c = p_item->cells[col];
+		const TreeItem::Cell &c = p_item->cells[col];
 
 		bool already_selected = c.selected;
 		bool already_cursor = (p_item == selected_item) && col == selected_col;
@@ -1990,7 +1990,7 @@ void Tree::text_editor_enter(String p_text) {
 	if (popup_edited_item_col < 0 || popup_edited_item_col > columns.size())
 		return;
 
-	TreeItem::Cell &c = popup_edited_item->cells[popup_edited_item_col];
+	TreeItem::Cell &c = popup_edited_item->cells.write[popup_edited_item_col];
 	switch (c.mode) {
 
 		case TreeItem::CELL_MODE_STRING: {
@@ -2041,7 +2041,7 @@ void Tree::value_editor_changed(double p_value) {
 		return;
 	}
 
-	TreeItem::Cell &c = popup_edited_item->cells[popup_edited_item_col];
+	TreeItem::Cell &c = popup_edited_item->cells.write[popup_edited_item_col];
 	c.val = p_value;
 	item_edited(popup_edited_item_col, popup_edited_item);
 	update();
@@ -2055,7 +2055,7 @@ void Tree::popup_select(int p_option) {
 	if (popup_edited_item_col < 0 || popup_edited_item_col > columns.size())
 		return;
 
-	popup_edited_item->cells[popup_edited_item_col].val = p_option;
+	popup_edited_item->cells.write[popup_edited_item_col].val = p_option;
 	//popup_edited_item->edited_signal.call( popup_edited_item_col );
 	update();
 	item_edited(popup_edited_item_col, popup_edited_item);
@@ -2467,7 +2467,7 @@ void Tree::_gui_input(Ref<InputEvent> p_event) {
 				}
 			} else {
 
-				TreeItem::Cell &c = popup_edited_item->cells[popup_edited_item_col];
+				const TreeItem::Cell &c = popup_edited_item->cells[popup_edited_item_col];
 				float diff_y = -mm->get_relative().y;
 				diff_y = Math::pow(ABS(diff_y), 1.8f) * SGN(diff_y);
 				diff_y *= 0.1;
@@ -2681,7 +2681,7 @@ bool Tree::edit_selected() {
 	popup_edited_item = s;
 	popup_edited_item_col = col;
 
-	TreeItem::Cell &c = s->cells[col];
+	const TreeItem::Cell &c = s->cells[col];
 
 	if (c.mode == TreeItem::CELL_MODE_CHECK) {
 
@@ -3072,7 +3072,7 @@ void Tree::item_selected(int p_column, TreeItem *p_item) {
 		if (!p_item->cells[p_column].selectable)
 			return;
 
-		p_item->cells[p_column].selected = true;
+		p_item->cells.write[p_column].selected = true;
 		//emit_signal("multi_selected",p_item,p_column,true); - NO this is for TreeItem::select
 
 		selected_col = p_column;
@@ -3086,7 +3086,7 @@ void Tree::item_selected(int p_column, TreeItem *p_item) {
 void Tree::item_deselected(int p_column, TreeItem *p_item) {
 
 	if (select_mode == SELECT_MULTI || select_mode == SELECT_SINGLE) {
-		p_item->cells[p_column].selected = false;
+		p_item->cells.write[p_column].selected = false;
 	}
 	update();
 }
@@ -3167,14 +3167,14 @@ void Tree::set_column_min_width(int p_column, int p_min_width) {
 
 	if (p_min_width < 1)
 		return;
-	columns[p_column].min_width = p_min_width;
+	columns.write[p_column].min_width = p_min_width;
 	update();
 }
 void Tree::set_column_expand(int p_column, bool p_expand) {
 
 	ERR_FAIL_INDEX(p_column, columns.size());
 
-	columns[p_column].expand = p_expand;
+	columns.write[p_column].expand = p_expand;
 	update();
 }
 
@@ -3422,7 +3422,7 @@ bool Tree::are_column_titles_visible() const {
 void Tree::set_column_title(int p_column, const String &p_title) {
 
 	ERR_FAIL_INDEX(p_column, columns.size());
-	columns[p_column].title = p_title;
+	columns.write[p_column].title = p_title;
 	update();
 }
 
@@ -3668,7 +3668,7 @@ String Tree::get_tooltip(const Point2 &p_pos) const {
 
 		if (it) {
 
-			TreeItem::Cell &c = it->cells[col];
+			const TreeItem::Cell &c = it->cells[col];
 			int col_width = get_column_width(col);
 			for (int j = c.buttons.size() - 1; j >= 0; j--) {
 				Ref<Texture> b = c.buttons[j].texture;