Hi Mike, The FFI reflect module [1] by Peter Cawley is very useful for serializing C data objects, e.g., for reading and writing HDF5 datasets of multi-dimensional arrays with struct element type. [1] https://github.com/corsix/ffi-reflect However, the module depends on LuaJIT-internal data structures that could change with new major releases. Would you consider including the functionality of the reflect module in the ffi.* API? Regards, Peter