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/modules/gridmap/grid_map.cpp b/modules/gridmap/grid_map.cpp
index 234a59e516..0c5df57d49 100644
--- a/modules/gridmap/grid_map.cpp
+++ b/modules/gridmap/grid_map.cpp
@@ -508,7 +508,7 @@ bool GridMap::_octant_update(const OctantKey &p_key) {
 				continue;
 			PhysicsServer::get_singleton()->body_add_shape(g.static_body, shapes[i].shape->get_rid(), xform * shapes[i].local_transform);
 			if (g.collision_debug.is_valid()) {
-				shapes[i].shape->add_vertices_to_array(col_debug, xform * shapes[i].local_transform);
+				shapes.write[i].shape->add_vertices_to_array(col_debug, xform * shapes[i].local_transform);
 			}
 
 			//print_line("PHIS x: "+xform);
@@ -758,7 +758,7 @@ void GridMap::_update_visibility() {
 	for (Map<OctantKey, Octant *>::Element *e = octant_map.front(); e; e = e->next()) {
 		Octant *octant = e->value();
 		for (int i = 0; i < octant->multimesh_instances.size(); i++) {
-			Octant::MultimeshInstance &mi = octant->multimesh_instances[i];
+			const Octant::MultimeshInstance &mi = octant->multimesh_instances[i];
 			VS::get_singleton()->instance_set_visible(mi.instance, is_visible());
 		}
 	}