C++ appdirs Interface

The cpp_addirs library provides an interface at the C++ level to the values in Chimera’s Python appdirs object. You link against the library with -L$(shlibdir) -lcpp_appdirs in your Makefile. You use the library by including cpp_appdirs/AppDirs.h in your code and calling cpp_appdirs::AppDirs::get() to get a const AppDirs instance. That instance has six const string attributes that correspond to the appdirs directory attributes and have the exact same names (e.g. user_data_dir).

The AppDirs class provides an important convenience function for generating file system paths based on the directory attributes that uses the appropriate path separator character for the operating system:

std::string AppDirs::form_path(std::initializer_list<std::string> path_components) const

Returns a path formed by joining the given strings with the appropriate path separator. Example usage:

std::string path = appdirs.form_path({appdirs.site_data_dir,
        "charge-database", "ATP.charges"});