Hello, I have a question to building boost. I have read now a lot of posts where it is written that with msvc the SECURE option is really slow. In some posts I have read that this option breaks the ABI and for that it is needed to build also the boost library with the right compiler switch. isn't it? 1) How I can build it with a custom compiler switch? sorry if it is documented, but I don't have found it... 2) Is it possible to add a make option(complete build) which builds a library with this switch and against which boost links automatically when the application defines _SECURE_SCL=0? Best regards Hansjörg