Constructing a vector of components only correctly initializes the first component

[DavidPfander-UniStuttgart]

Constructing a vector of components only correctly initializes the first component. There seem to be some std::move calls that hinder the construction of the other components, as they receive values that have been moved away, see the following example:

#include <iostream>
#include <hpx/hpx_init.hpp>
#include <hpx/include/actions.hpp>
#include <hpx/include/async.hpp>
#include <hpx/include/util.hpp>
#include <hpx/include/components.hpp>

struct component_server: hpx::components::component_base<
  component_server> {

  std::vector<double> A;

  component_server() {
  }

  component_server(const std::vector<double> &A) :
    A(A) {
    std::cout << "initializing A A.s: " << A.size() << std::endl;
  }

  void do_stuff() {

  }

  HPX_DEFINE_COMPONENT_ACTION(component_server, do_stuff,
                  do_stuff_action);
};

HPX_REGISTER_ACTION_DECLARATION(component_server::do_stuff_action);

struct component_client: hpx::components::client_base<
  component_client, component_server> {

  using base_type = hpx::components::client_base<
    component_client, component_server>;

  component_client(const hpx::naming::id_type& id): base_type(id) {

  }

  hpx::future<void> do_stuff_client() {
    return hpx::async<component_server::do_stuff_action>(
                             get_id());
  }
};

HPX_REGISTER_COMPONENT(hpx::components::component<component_server>,
        component_server_component);

HPX_REGISTER_ACTION(component_server::do_stuff_action);

int hpx_main() {

  std::vector<double> A(1000);

  std::vector<component_client> mass_construct = hpx::new_<
    component_client[]>(hpx::find_here(), 10, A).get();

  return hpx::finalize();
}

int main(int argc, char **argv) {
// Initialize and run HPX
 return hpx::init(argc, argv);
}

Expected output:

initializing A A.s: 1000
initializing A A.s: 1000
initializing A A.s: 1000
initializing A A.s: 1000
initializing A A.s: 1000
initializing A A.s: 1000
initializing A A.s: 1000
initializing A A.s: 1000
initializing A A.s: 1000
initializing A A.s: 1000

Actual output:

initializing A A.s: 1000
initializing A A.s: 0
initializing A A.s: 0
initializing A A.s: 0
initializing A A.s: 0
initializing A A.s: 0
initializing A A.s: 0
initializing A A.s: 0
initializing A A.s: 0
initializing A A.s: 0

[AntonBikineev]

https://github.com/STEllAR-GROUP/hpx/blob/master/hpx/runtime/components/server/runtime_support.hpp#L656
These moves cause this problem

[hkaiser]

@AntonBikineev Yes, thanks. The arguments of this function could also be converted to forwarding references.

[AntonBikineev]

@hkaiser I've thought about it too, but it seems to me there should still be explicit copies in that loop

[hkaiser]

@AntonBikineev yes, I agree. I'll submit a patch later today.