Comment by kibwen

You won't end up with a mix in the same program unless the code that you're using to parse the config is deliberately written to allow a mix, which no sane code owner would allow. And even if it did, that still wouldn't be enough to outweigh the aforementioned downside of the impedance mismatch between the """types""" in your config file format (how many bits wide is this integer? how much precision is this float? how is nullable data represented?) and the types in your actual language where it matters.