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, 2 insertions, 2 deletions

diff --git a/editor/plugins/animation_state_machine_editor.cpp b/editor/plugins/animation_state_machine_editor.cpp
index 04bd5f0cec..ee450333c8 100644
--- a/editor/plugins/animation_state_machine_editor.cpp
+++ b/editor/plugins/animation_state_machine_editor.cpp
@@ -679,7 +679,7 @@ void AnimationNodeStateMachineEditor::_state_machine_draw() {
 		Ref<StyleBox> sb = name == selected_node ? style_selected : style;
 		int strsize = font->get_string_size(name).width;
 
-		NodeRect &nr = node_rects[i];
+		NodeRect &nr = node_rects.write[i];
 
 		Vector2 offset = nr.node.position;
 		int h = nr.node.size.height;
@@ -771,7 +771,7 @@ void AnimationNodeStateMachineEditor::_state_machine_pos_draw() {
 	if (idx == -1)
 		return;
 
-	NodeRect &nr = node_rects[idx];
+	const NodeRect &nr = node_rects[idx];
 
 	Vector2 from;
 	from.x = nr.play.position.x;