After you are done installing HPX, you should be able to build the following program. It prints Hello HPX World! on the locality you run it on.

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

int hpx_main(boost::program_options::variables_map&)
{
    // Say hello to the world!
    hpx::cout << "Hello World!\n" << hpx::flush;

    return hpx::finalize(); // Initiate shutdown of the runtime system.
}

int main(int argc, char* argv[])
{
    // Configure application-specific options.
    boost::program_options::options_description desc_commandline(
        "usage: simplest_hello_world [options]");

    return hpx::init(desc_commandline, argc, argv); // Initialize and run HPX.
}

Copy the text of this program into a file called hello_world.cpp.

Now, in the directory where you put hello_world.cpp, issue the following commands (where $HPX_LOCATION is the CMAKE_INSTALL_PREFIX you used while building HPX):

$ export PKG_CONFIG_PATH=$PKG_CONFIG_PATH:$HPX_LOCATION/lib/
$ c++ -o hello_world hello_world.cpp `pkg-config --cflags --libs hpx_application` -lhpx_component_iostreams -DHPX_APPLICATION_NAME=hello_world

	Important
	When using pkg-config with HPX, the pkg-config flags must go after the -o flag.

To test the program, type:

$ ./hello_world

which should print Hello HPX World! and exit.