[boost] Is there a preferred order of include files? Boost or std first?

I have been wondering if there is a preferred order of include files? Should I write (for example): #include <iostream> #include <boost/test/unit_test.hpp> or #include <boost/test/unit_test.hpp> #include <iostream> Or does it not matter? There seems no clear consistency in Boost files Paul PS IMO It would helpful to those reading code to have a consistent order. -- Paul A Bristow Prizet Farmhouse, Kendal, Cumbria UK LA8 8AB Phone and SMS text +44 1539 561830, Mobile and SMS text +44 7714 330204 mailto: pbristow@hetp.u-net.com http://www.hetp.u-net.com/index.html http://www.hetp.u-net.com/Paul%20A%20Bristow%20info.html