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, 4 insertions, 4 deletions

diff --git a/modules/gdnative/register_types.cpp b/modules/gdnative/register_types.cpp
index d18297f2f8..ae1a218392 100644
--- a/modules/gdnative/register_types.cpp
+++ b/modules/gdnative/register_types.cpp
@@ -341,10 +341,10 @@ void register_gdnative_types() {
 
 		Ref<GDNativeLibrary> lib = ResourceLoader::load(path);
 
-		singleton_gdnatives[i].instance();
-		singleton_gdnatives[i]->set_library(lib);
+		singleton_gdnatives.write[i].instance();
+		singleton_gdnatives.write[i]->set_library(lib);
 
-		if (!singleton_gdnatives[i]->initialize()) {
+		if (!singleton_gdnatives.write[i]->initialize()) {
 			// Can't initialize. Don't make a native_call then
 			continue;
 		}
@@ -374,7 +374,7 @@ void unregister_gdnative_types() {
 			continue;
 		}
 
-		singleton_gdnatives[i]->terminate();
+		singleton_gdnatives.write[i]->terminate();
 	}
 	singleton_gdnatives.clear();