hpx/hpx.hpp does not include hpx/include/iostreams.hpp

[eschnett]

I believe that the header file hpx/hpx.hpp should included all other header files for convenience. However, hpx::cout is not defined after including <hpx/hpx.hpp>.

[hkaiser]

That's intentional as iostreams is a separate component which is completely independent from the core HPX libraries. Please include it separately, if needed:

#include <hpx/hpx.hpp>
#include <hpx/include/iostreams.hpp>