How to specify whether to emit optional struct name during serialization?

I see no option for that here
https://docs.rs/ron/0.5.1/ron/ser/struct.PrettyConfig.html

but I think there should be one..

required=True is of little use if it only raises exception when user attempts to retrieve the value. Instead, should be a way for user to validate all configuration items once they have finished loading configuration with an explicit config.validate() call. This should not happen automatically because you never know when user has finished initialising and loading the configuration.