From: Paul Mensonides
All of this is the status quo of the library. There are two other models that are superior in terms of ease of use and avoidance of these types of issues.
The first of these, I use in a different (far more powerful) preprocessor library. The problem with this model is that it isn't portable to broken preprocessors (which are heavily used by users of Boost--e.g. VC++).
The second alternative model revolves around automatically deducing all algorithm states whenever they are needed. [snip].
There is a third model - don't use the C++ preprocessor, but use a more general purpose text transformation tool like M4, or awk/perl/python, or a custom tool written with bison or boost::Spirit. I'm not knocking the preprocessor library with that suggestion. An external tool would be no use for a library like boost where it is very difficult to control the compilation system. Furthermore, the heroics involved in implementing the boost preprocessor library mean that using it is remarkably simple. I just wanted to point out that there is always another option. -- Martin Bonner Martin.Bonner@Pitechnology.com Pi Technology, Milton Hall, Ely Road, Milton, Cambridge, CB4 6WZ, ENGLAND Tel: +44 (0)1223 203894