Hi, I have a few questions/nitpicks regarding Boost.Predef: - I see that all headers have extension .h. Why is it not .hpp, like with the rest of Boost? It this intentional? - There is a tab in predef/version_number.h. There are also tabs in tests. - There are __SunOS_5_10, __SunOS_5_11 and similar macros defined on Solaris, which allow to detect OS version. These are not always available but I think SunPro defines them. Could these macros be used to select the proper OS version? - If I'm not mistaken, BOOST_COMP_GNUC and BOOST_COMP_MSVC will get defined not only for the real GCC and MSVC but also for pretenders. Is this intentional? If so, could we have special macros to detect these particular compilers? Boost.Config defines BOOST_MSVC and BOOST_GCC for this purpose. - There is considerable overlap with Boost.Config. Is there any plan to reduce the duplication? Maybe move some things from Boost.Config to Boost.Predef?