This project is a C++ port of the FORTRAN library SLALIB. This is what the original
library's documentation says about its purpose:
SLALIB is a library used by writers of positional-astronomy applications. Most of the 188 routines are concerned with astronomical position and time, but a number have wider trigonometrical, numerical or general applications.
The original (FORTRAN) library comes with extensive documentation, available from many sites; for instance, here. Not only has it quite extensive coverage of every function, but is also contains large section explaining math behind library routines. That said, in our opinion, the very best source of information on positional astronomy and related topics is the Fundamental Astronomy book by H. Karttunen et. al. available from Springer. Highly recommended.
The FORTRAN source code used for the port is SLABIB version 2.5-7 bundled
with the starlink software by P.T. Wallace that can be found on
GitHub.
Hope you will find this C++ library useful.
The CyberHULL Team.