The tutorial (http://software.intel.com/en-us/articles/sc10-tutorial-intel-arbb/) mentions user_types, structs composed of arbb types. It seems to me that the arbb-vmapi only handles dense of basetypes. When using the C++ frontend (ArBB) to the vmapi are dense "compiled" into several dense containers of base types ? Essentially turning dense_of_struct into struct_of_dense. Is there a doc describing how this works?