improvements, in example from @codebrainz, now mem_func also highlighted
In my example, I only meant `some_function` should be highlighted in each of the 3 lines, assuming it's defined like:
```c++ void some_function() {} // or c++ member function void TheClass::some_function() {} ```
I don't think `mem_fun` should be highlighted as a function since it's most likely a class name (would have to check libsigc++ code).