That's interesting. Since the compiler is determined before the standard library, it would still be possible to put the definition in boost/config/stdlib/dinkumware.hpp, like so

#if defined(BOOST_MSVC) && (BOOST_MSVC >= 1310) #define BOOST_STD_EXTENSION_NAMESPACE stdext #endif

Maybe one should check _CPPLIB_VER for good measure. This sounds reasonable. What do you think?

That sounds reasonable, I'll commit the changes to the main development branch when I get a chance, Intel uses Microsoft's headers (at least I think they do), so it'll be the same for them, but other vendors that use Dinkumware don't necessarily do the same thing (although again it's hard to be definitive). Thanks, John