[dig1]

The best thing about C++ preprocessor is that it is dumb. Text goes in, text goes out. Easy to debug, simple rules. Anything I saw as an alternative either requires a significant amount of code, bending C++ rules, or specialized tools to see what is going on.

Java tried so hard to "do the right thing" by abolishing the preprocessor, and we ended up with another preprocessor called IDE, unnecessary code patterns, and (oh my) Maven profiles for conditional compilation (among other things).

[humanrebar]

On the other hand, the preprocessor is so dumb that having a normal variable or enum named "OK" or "STATUS" is a risk, even if all of your dependencies are clean. All it takes is a user to include your header and some header that #defines any name in your header to be something else.

So that means you really need to name your preprocessor symbols (and any other all-caps names, because that's the convention) in ways that probably won't collide. Like MYLIB_OK.

So it starts off dumb, but then you have to start layering on convention and defensive programming immediately. And it complicates entire other features of the language, naming constants and enumerated values especially.

[mhh__]

D has no preprocessor and has none of those problems.