simgrid::xbt::signal<void(simgrid::kernel::activity::ExecImplPtr, simgrid::s4u::Host*)>
simgrid::kernel::activity::ExecImpl::on_migration;
simgrid::xbt::signal<void(simgrid::kernel::activity::ExecImplPtr, simgrid::s4u::Host*)>
simgrid::kernel::activity::ExecImpl::on_migration;