There seems to be a phobia about macros. People keep reinventing them but
are very wary of calling them macros.

If you have a look at the java world, there is a large amount of code
generation going on. There is also an amazing amount of patching of object
files (.class files) as well.

C++ has templates, which have reportedly now reached the stage of being
Turing-complete. But macros are still frowned upon.

There are two explanations I have seen:

1. If you use macros, you are almost defining a new language. You have to
look at the macro definition to see what the code does.

This argument seems equally applicable to the use of any facility beyond
in-line code (eg using other classes). And most languages with macros have
the ability to expand the macro for viewing.

In any case, as Paul Graham never tires of pointing out, maybe you do want
to create a new language, a domain specific language. This may be a really
good idea.

What puzzles me is that people accept patching class files but will not
accept macros. How do you look at the source of a patched class file?

2. In the early days, people went too far with macros and the code became
unmaintainable.

This seems to be just an argument for discipline in programming projects.

Is there any other explanation? Here is Sun's explanation for no macros in
Java.

http://www.artima.com/weblogs/viewpost.jsp?thread=5246