How to pass “literal” integers by reference in C++ (Newbie)

Question

Edit: As many people have pointed out, pass-by-reference isn\'t generally appropriate as an optimisation for primitive types. This is excellent to know, so

Answer 1

You seem to already be familiar with the problems of copy-by-value, so you've eliminated copy-by-value. And now you're confused that passing raw values fails?

Now I'm lost.