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/core/variant_call.cpp b/core/variant_call.cpp
index e6f36ecbf1..c150ea9c00 100644
--- a/core/variant_call.cpp
+++ b/core/variant_call.cpp
@@ -64,7 +64,7 @@ struct _VariantCall {
 			if (arg_count == 0)
 				return true;
 
-			Variant::Type *tptr = &arg_types[0];
+			const Variant::Type *tptr = &arg_types[0];
 
 			for (int i = 0; i < arg_count; i++) {