Check a vector before clear?

Question

I'm not sure, but I think I've read that you should only delete a vector if it's not empty. So now I always check before I delete a vector:

if (!vector.empty()) {
    vector.clear();
}

However, I no longer find anything about whether this step is unnecessary.

Is it forbidden to use clear on an empty vector?

Answer 1

The check is unneeded,

and decrease readability IMO.