Seems that the version of wave in current boost 1.33.1 release candidate crashes and hangs lot less than the one in 1.33.0 release, thanks. What is great it does not crash or refuse on its own code anymore. As for big integers ... i am no expert, but maybe it is not best idea to use implementations that contain assembler parts in cross-platform libraries like boost. 15 years ago it was very common to use manually optimized code in critical parts, these days however C++ compilers do optimizations all better and better. Got pair of questions too but no need to answer if no and no. ;-) Is there simple way to setup bjam to preprocess the whole boost library with wave? So to get the impression how good it is. Is there an option to direct the output into *.i files instead of stdout? I currently do it with -o option just that .i file seems to be default for most other C++ preprocessors. Getting slightly bored to type twice. Thanks again.