That makes even less sense, what "extra bit of code" are you talking about? monostate is not designed to be used with optional: although there's the odd case wh

That makes even less sense, what "extra bit of code" are you talking about? monostate is not designed to be used with optional: although there's the odd case where that's useful an optional<monostate> is bijective to a boolean, and because C++ does not have zero-sized types it's less efficient (as it takes two bytes).