This gdextension was ported from the Goost Engine Extension. See:

https://github.com/goostengine/goost/blob/gd3/core/types/linked_list.h

https://github.com/goostengine/goost/blob/gd3/core/types/linked_list.cpp

For compilation instructions, see:

https://docs.godotengine.org/en/stable/tutorials/scripting/gdextension/gdextension_cpp_example.html