validDisplay is used to express when the screen is displaying a real notification, instead of displaying that there are no notifications. When it is not displaying a notification, the currentId is always invalid. Use std::optional to replace validDisplay and express that currentId may be invalid.
validDisplay is used to express when the screen is displaying a real notification, instead of displaying that there are no notifications. When it is not displaying a notification, the currentId is always invalid. Use std::optional to replace validDisplay and express that currentId may be invalid.
Set CXX standard to 17 to support std::optional.