[boost] [GIL] 3d image support

Hi, As I read from the documentation, GIL supports N-dimensional image concepts but lacks an Implementation of 'PointNDConcept', 'RandomAccessNDImageViewConcept', 'RandomAccessNDImageConcept' and 'RandomAccessNDLocatorConcept' for 3d images. Has anybody implemented these as extension to GIL or is it on the TODO list? What do you think will be the effort to implement them? Is it a no-brainer by just implementing the concepts similar to the 2d counterparts or will there be some difficulties from the design? Greetings, Falco