YAML or TSV depending on whether your configuration looks like a rectangular table. If you want extreme flexibility using C++ as the main language, take a look

YAML or TSV depending on whether your configuration looks like a rectangular table. If you want extreme flexibility using C++ as the main language, take a look at my project: https://github.com/jzwinck/pccl https://github.com/jzwinck/pccl It lets you configure your C++ apps using Python. Config items can even be Python functions.