Your code is not the same as my code and you're probably new to C++. I suggest trying two changes:

1) Replace max("a", "b") with max("b", "a"). Run it, look closely at the result, and be enlightened.

2) Replace max("a", "b") with max<string>("a", "b"). Run it, look at the result, and be enlightened in a different way.

As a small hint, your code invokes unspecified behavior, while my code invokes undefined behavior.

If this exercise doesn't put the fear of C++ into you, then I don't know what will :-)