Isn't it possible to define modifiers in libraries? I'm really asking myself why, because thats some functionality you would need over and over again.
If I would like to hypothetically implement some
ownable modifier and let that be used in many of my contracts, I would have to implement it in every of my contracts or use another contract (no library), that provides the modifier.
I've seen https://github.com/OpenZeppelin/openzeppelin-solidity/blob/master/contracts/ownership/Ownable.sol and they implement the functionality also as a contract rather than a function as, I guess, modifiers cannot be accessed from Solidity libraries?
My question: should I now implement my modifiers in my abstract contracts or define modifiers in a contract on its own like the Zeppelin guys did? Whats the up/downsides?