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.

1 files changed, 54 insertions, 54 deletions

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;