[drt1245]

The problem is a loss of verbosity. The next person looking at the code isn't necessarily going to know how MAX is defined, and saving 1 line of code isn't worth making it less clear.

That said, for me, your code would be clear, as not being in all caps, I would assume it's a function and therefore doesn't have the same weakness.

As someone else pointed out, there's no way you can look at MAX(0,f()) and know that it's enforced that f() is only used once within the macro.