When a Vector of Vectors gets resized the 'this' pointer of the Vectors
change. This means that the VectorWriteProxy _parent references get
invalidated. Thanks a lot to @ibrahn for finding the root cause of this.
To fix this we now create a pointer to CowData in Vector (which won't
change when the vectors move) and pass that to the write proxy also.
This fixes#20475
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.
Hein-Pieter van Braam