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, 1 insertions, 1 deletions

diff --git a/scene/2d/animated_sprite.h b/scene/2d/animated_sprite.h
index f6586aff36..cc49465403 100644
--- a/scene/2d/animated_sprite.h
+++ b/scene/2d/animated_sprite.h
@@ -113,7 +113,7 @@ public:
 		ERR_FAIL_COND(p_idx < 0);
 		if (p_idx >= E->get().frames.size())
 			return;
-		E->get().frames[p_idx] = p_frame;
+		E->get().frames.write[p_idx] = p_frame;
 	}
 	void remove_frame(const StringName &p_anim, int p_idx);
 	void clear(const StringName &p_anim);