All routines are implemented purely in C (C23) as static functions in headers inside ./include/.
Tests use Google's GoogleTest 1.15.2 (included in ./tests/googletest/) and require a C++ compiler with C++20 support.
Tests for routines in the C headers are implemented in the C++ source files with the same name in the ./tests/ directory.
Reference : Mastering Algorithms with C (1999) Kyle Loudon