C++ GIS library to convert WGS84 and Stereo70 coordinates bidirectionally.

It uses Helmert transformations for datum shifts (e.g., WGS84 ECEF <-> Pulkovo ECEF) and handles the Stereo70 projection math based on the Krasovsky ellipsoid.

Includes essential GIS constants, coordinate types, and ellipsoid parameters, built with modern C++ features.

Template based header-only C++20 library.