In my opinion, if a parent can’t guarantee that they never smack in anger, they have no business doing it. And once a child gets above toddler-hood it ceases being necessary at all. I don’t think it’s ever the best option.
It’s not possible to say with certainty ‘I was smacked and I turned out fine’. I used to say that… But now I suspect that my scrupulosity/perfectionism/subconcious view of God as a judge rather than loving father… it stems from being smacked in anger, often over mistakes rather than boldness, because my parent couldn’t control their temper.
Unless you have the patience of a saint, you risk altering your child’s personality forever by unjust corporal punishment.
And I’m just talking about slapping toddlers and elementary school kids in anger. The OP was most definitely abused based on what she has told us. I’m sorry you had to go through that OP. Please, if you haven’t, have a chat with a councellor.