HDU classes

Every HDU type subclasses rustfits.HDU and shares the header, index, extname, extver, and has_data accessors. Image and table types add their own data-access surface.

The compressed image/table types each subclass their uncompressed counterpart, so isinstance() against the base (isinstance(hdu, ImageHDU), isinstance(hdu, TableHDU)) holds for both compressed and uncompressed instances.

• HDU (base class)
• ImageHDU
• CompressedImageHDU
• TableHDU
• CompressedTableHDU
• AsciiTableHDU
• Column subset handles