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/scene/3d/vehicle_body.h b/scene/3d/vehicle_body.h
index 1ac3693cc4..68fbf8d873 100644
--- a/scene/3d/vehicle_body.h
+++ b/scene/3d/vehicle_body.h
@@ -168,7 +168,7 @@ class VehicleBody : public RigidBody {
 		btVehicleWheelContactPoint(PhysicsDirectBodyState *s, PhysicsBody *body1, const Vector3 &frictionPosWorld, const Vector3 &frictionDirectionWorld, real_t maxImpulse);
 	};
 
-	void _resolve_single_bilateral(PhysicsDirectBodyState *s, const Vector3 &pos1, PhysicsBody *body2, const Vector3 &pos2, const Vector3 &normal, real_t &impulse, real_t p_rollInfluence);
+	void _resolve_single_bilateral(PhysicsDirectBodyState *s, const Vector3 &pos1, PhysicsBody *body2, const Vector3 &pos2, const Vector3 &normal, real_t &impulse, const real_t p_rollInfluence);
 	real_t _calc_rolling_friction(btVehicleWheelContactPoint &contactPoint);
 
 	void _update_friction(PhysicsDirectBodyState *s);