I have one method which accepts `const char *` as shown below - 

```
bool get_data(const char* userid) const;

```

Now below is my for loop in which I need to call `get_data` method by passing `const char *`. Currently below for loop uses `uint64_t`. I need to convert this `uint64_t` to `const char *` and then pass to `get_data` method.

```
for (TmpIdSet::iterator it = userids.begin(); it != userids.end(); ++it) {
    // .. some code
    // convert it to const char *
    mpl_files.get_data(*it)
}

```

Here `TmpIdSet` is `typedef std::set<uint64_t> TmpIdSet;`

So my question is how should I convert `uint64_t` in the above code to `const char *`?