catching std::exception by reference?

Question

I have a silly question. I read this article about std::exception http://www.cplusplus.com/doc/tutorial/exceptions/

On catch (exception& e), it says:

Answer 1

No the & has absolutely no bearing on the polymorphic nature of exception handlers. Their wording is very poor, it does seem to indicate that the & is somehow responsible. This is not the case. You are correct, & just passes by reference which is a tad more efficient.

Also as a general rule, you should really try to avoid cplusplus.com.

Updated link: What's wrong with cplusplus.com