[Numpy-discussion] read-only or immutable masked array

Hi, I use masked arrays to mark missing values in data and found it very convenient, although sometimes counterintuitive. I'd like to make a pool of masked arrays (shared between several processing steps) read-only (both data and mask property) to protect the arrays from accidental modification (and the array users from hours of debugging). The regular ndarray trick array.flags.writeable = False is perfectly fine, but it does not work on ma-s. Moreover, mask hardening only protects masked elements, and does not raise error (as I'd expect). Could you recommend an easy way to set an ma read-only? Thanks, Gregorio