Hi! I've been working on using notifier() to register a custom validator for an option. If the validator doesn't pass, it throws invalid_option_value. The issue I'm running in to though is that I do not have an context to report which option had a problem- I'm actually also really just abusing the notifier system as well, as I throw invalid_option_value with a descriptive message instead of just the option value. If I pass in an already bogus value, such as passing in a string to an int option, I get something like this: Error processing options: in option 'connect_timeout': invalid option value 'eggs' So it seems there are places where the code is validating options (seemingly just from any_cast) with context of which option is being validated. Is there some place I'm missing to hook a validator in where throwing an exception would properly pick up option name context? I saw this comment: /* We call validate so that if user provided a validator for class T, we use it even when parsing vector<T>. */ What I'd really love would be if I could call something like validator(some_validator).validator(some_other_validator), and that those would be passed some sort of context. Specifically, in the code we're working on replacing, it's quite easy to specify a min and max value for an integer option, and I'm trying to figure out a good way to keep this without requiring folks to write a completely independent notifier function for each option that emits its own error message. Any thoughts on where I might want to go with this?