Just as a note: you could use `foreach` here, which I define as an alias to `BOOST_FOREACH`, and use `push_back` instead of assigning with an index.

it would look like

```cpp
foreach (std::string scan_topic, scans_in)
{
  sub_.push_back(root_nh_.subscribe<sensor_msgs::LaserScan>(scan_topic, 10,
                 boost::bind(&LaserMuxNode::scansCB, this, _1));
}
```