This module assists in generating wrappers around system functionality,
such as socket() types or ioctl() calls, where the only interesting
features required are the values of some constants or layouts of structures
normally only known to the C header files. Rather than writing an entire XS
module just to contain some constants and pack/unpack functions, this
module allows the author to generate, at module build time, a pure perl
module containing constant declarations and structure utility functions.
The module then requires no XS module to be loaded at run time.