Why should pop() take an argument?

Question

Quick background
I\'m a Java developer who\'s been playing around with C++ in my free/bored time.

Preface
In C++, you often see

Answer 1

IMO, a good signature for the eqivalent of Java's pop function in C++ would be something like:

boost::optional pop();

Using option types is the best way to return something that may or may not be available.