When I think of a "post-processor", I think of something like the Java annotation processing mechanism. In Java, you can annotate classes, interfaces or methods with user-defined attributes (with names like @Test or @Entity). javac then invokes annotation processors (Java programs) that can process a read-only tree of declarations and read their annotations. While annotation processors are not allowed to modify the original source files, they are allowed to generate new files that get passed to the compiler, potentially triggering further annotation processing. While limited by only being able to generate new files, this is essentially a type- and syntax-aware post-processor. To be honest, I haven't seen it be used for very much outside of persistence frameworks and service registration (e.g., @ServiceProvider in NetBeans), but it seems very powerful. I'm not sure how it would be implemented for C++ (a g++ plugin?), but it would seem to be less work than a C++ interpreter and would allow more powerful/easier computation at compile-time. Annotations could perhaps be implemented using the C++0x attribute syntax. --Jeffrey Bosboom