Which is correct? catch (_com_error e) or catch (_com_error& e)?

Question

Which one should I use?

catch (_com_error e)  

or

catch (_com_error& e)

Answer 1

Also, note that, when using MFC, you may have to catch by pointer. Otherwise, @JaredPar's answer is the way you should normally go (and hopefully never have to deal with things that throw a pointer).