SafeArrayPtr

auto lines = SafeArrayPtr<IProfibusLinePtr>(profiMaster->GetProfibusLines());
if(lines.size() != 1) {
    ASSERT(false);  //< We only support one line at the moment.
    return nullptr;
}
auto line = lines.at(0);

auto slaves = SafeArrayPtr<IProfibusSlavePtr>(line->GetProfibusSlaves());
for_each(begin(slaves), end(slaves), [&](IProfibusSlavePtr slave) {
    if(auto found = searchInProfiSlave( slave, id )) {
        retDevice = found;
        break;
    }
});