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.

4 files changed, 5 insertions, 5 deletions

diff --git a/modules/mono/csharp_script.cpp b/modules/mono/csharp_script.cpp
index 8471083f49..7d7028a7a6 100644
--- a/modules/mono/csharp_script.cpp
+++ b/modules/mono/csharp_script.cpp
@@ -523,7 +523,7 @@ Vector<ScriptLanguage::StackInfo> CSharpLanguage::stack_trace_get_info(MonoObjec
 	si.resize(frame_count);
 
 	for (int i = 0; i < frame_count; i++) {
-		StackInfo &sif = si[i];
+		StackInfo &sif = si.write[i];
 		MonoObject *frame = mono_array_get(frames, MonoObject *, i);
 
 		MonoString *file_name;
diff --git a/modules/mono/editor/bindings_generator.cpp b/modules/mono/editor/bindings_generator.cpp
index 6819c0abe8..76907451e7 100644
--- a/modules/mono/editor/bindings_generator.cpp
+++ b/modules/mono/editor/bindings_generator.cpp
@@ -1650,7 +1650,7 @@ Error BindingsGenerator::_generate_glue_method(const BindingsGenerator::TypeInte
 								   "\t\tvarargs.set(i, GDMonoMarshal::mono_object_to_variant(elem));\n"
 								   "\t\t" C_LOCAL_PTRCALL_ARGS ".set(");
 				p_output.push_back(real_argc_str);
-				p_output.push_back(" + i, &varargs[i]);\n\t" CLOSE_BLOCK);
+				p_output.push_back(" + i, &varargs.write[i]);\n\t" CLOSE_BLOCK);
 			} else {
 				p_output.push_back(c_in_statements);
 				p_output.push_back("\tconst void* " C_LOCAL_PTRCALL_ARGS "[");
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);