Much needed function needed for clone stamp tool!

I have been using Adobe Photoshop as a photographer and designer for many years. Something which I have needed and would have used nearly every day is when I need to clone one side of a person or item to the other side, due to imperfections on the one side.
I have to cut it out and flip it around and sometimes have to blend the access off.

IF the clone stamp tool had a mirror image capability - this will fix all this in one action!!!!!

I surely will use it constantly, and (I am not sure but) I do not think any competitor has something similar.