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/servers/physics/space_sw.h b/servers/physics/space_sw.h
index 2452d6a187..4d864e9a51 100644
--- a/servers/physics/space_sw.h
+++ b/servers/physics/space_sw.h
@@ -186,7 +186,7 @@ public:
 	void set_debug_contacts(int p_amount) { contact_debug.resize(p_amount); }
 	_FORCE_INLINE_ bool is_debugging_contacts() const { return !contact_debug.empty(); }
 	_FORCE_INLINE_ void add_debug_contact(const Vector3 &p_contact) {
-		if (contact_debug_count < contact_debug.size()) contact_debug[contact_debug_count++] = p_contact;
+		if (contact_debug_count < contact_debug.size()) contact_debug.write[contact_debug_count++] = p_contact;
 	}
 	_FORCE_INLINE_ Vector<Vector3> get_debug_contacts() { return contact_debug; }
 	_FORCE_INLINE_ int get_debug_contact_count() { return contact_debug_count; }