I'm using MS Visual Studio 2005 to work on some legacy code that has its origins back in 16-bit Windows, and relies on the /Zp2 switch to align fields in structures in the same way as earlier versions. One of the more recent modules uses boost::format, and this has compiled correctly and been working with Boost 1.34.1. I'm trying to bring the project up-to-date using 1.37, and I am getting BOOST_STATIC_ASSERT reports when I include boost/format.hpp. I don't have to *use* format in my code, just including boost/format.hpp in a "Hello world" program is sufficient to trigger the error when using /Zp2 Is this to be expected? Is there a workaround? I know we should really use explicit pack pragmas around the structures that have to be packed in this particular way, but there are too many of them -- and they're defined all over the code -- for this to be a simple or safe process ... /Zp2 has always worked fine in the past. Cheers, Daniel (Just a user -- not to be confused with the Boost contributor of the same name)