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/modules/visual_script/visual_script_flow_control.cpp b/modules/visual_script/visual_script_flow_control.cpp
index 0f58a20c00..7535f37ffc 100644
--- a/modules/visual_script/visual_script_flow_control.cpp
+++ b/modules/visual_script/visual_script_flow_control.cpp
@@ -684,7 +684,7 @@ bool VisualScriptSwitch::_set(const StringName &p_name, const Variant &p_value)
 		int idx = String(p_name).get_slice("/", 1).to_int();
 		ERR_FAIL_INDEX_V(idx, case_values.size(), false);
 
-		case_values[idx].type = Variant::Type(int(p_value));
+		case_values.write[idx].type = Variant::Type(int(p_value));
 		_change_notify();
 		ports_changed_notify();