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.

2 files changed, 3 insertions, 3 deletions

diff --git a/modules/mono/mono_gd/gd_mono.cpp b/modules/mono/mono_gd/gd_mono.cpp
index 0f4e211be5..f564b93f8f 100644
--- a/modules/mono/mono_gd/gd_mono.cpp
+++ b/modules/mono/mono_gd/gd_mono.cpp
@@ -77,12 +77,12 @@ void setup_runtime_main_args() {
 	Vector<char *> main_args;
 	main_args.resize(cmdline_args.size() + 1);
 
-	main_args[0] = execpath.ptrw();
+	main_args.write[0] = execpath.ptrw();
 
 	int i = 1;
 	for (List<String>::Element *E = cmdline_args.front(); E; E = E->next()) {
 		CharString &stored = cmdline_args_utf8.push_back(E->get().utf8())->get();
-		main_args[i] = stored.ptrw();
+		main_args.write[i] = stored.ptrw();
 		i++;
 	}
 
diff --git a/modules/mono/mono_gd/gd_mono_class.cpp b/modules/mono/mono_gd/gd_mono_class.cpp
index 53d6b7074c..ad74f73d74 100644
--- a/modules/mono/mono_gd/gd_mono_class.cpp
+++ b/modules/mono/mono_gd/gd_mono_class.cpp
@@ -503,7 +503,7 @@ GDMonoClass::~GDMonoClass() {
 					}
 				}
 
-				deleted_methods[offset] = method;
+				deleted_methods.write[offset] = method;
 				++offset;
 
 				memdelete(method);