What I mean is: some boolean flags are perfect for the real world phenomenon they are representing e.g. is_light_on makes you understand perfectly that when it is true the light is on and when it is false the light is off.
There are other cases in which if you didn’t write the code and you don’t read any additional documentation, everything is not clear just by looking at the variable name e.g. is_person_standing, when true it’s clear what that means but when false, is the person sitting? Lying? Kneeling?
I’m obviously not talking about cases in which there are more states, boolean would of course not be a good solution in those cases. I’m talking about programs in which there are only two states but it’s not obvious, without external knowledge, which ones they are.
PolicyCancelledByCarrier
If canx notice has been received, processed, blah blah, eventually it’s set to true.
If/when a reinstatement is received, set to false.
Zero ambiguity, something along that line saved my tail when working with devs in different countries with different insurance customs.
Carrier sent letter telling policy holder to get bent because “fuck you, pay me?” Field is true.
Otherwise, or with reinstatement letter, field true.