I am using `gdb` and I'd like to know in which point of a `std::string` the iterator I am inspecting is.

E.G. Is `it` at 2nd or 3rd position of the string?

I tried to call `std::distance` but it doesn't work.

```
const std:string &cs;
std::string::const_iterator it;

(gdb) call std::distance(cs.begin(), it);
No Symbol "distance" in namespace "std"

```

Do you know how to achieve that?