Well, there is a way to have them on the stack even with PImpl: http://www.gotw.ca/gotw/028.htm http://www.gotw.ca/gotw/028.htm However I'd say it's an ugly ha

Well, there is a way to have them on the stack even with PImpl: http://www.gotw.ca/gotw/028.htm http://www.gotw.ca/gotw/028.htm However I'd say it's an ugly hack which should only ever be used if you _really_ need the performance.