Used in `ATL::CStringW` and `ATL::CStringA`, for example:
```
ATL::CStringW cswItemText = "";
cswItemText.Preallocate(64);
SendDlgItemMessageW(pdis->CtlID, LB_GETTEXT, pdis->itemID, reinterpret_cast<LPARAM>(cswItemText.GetBuffer()));
cswItemText.ReleaseBuffer();
```
This public function is used to allocate memory for the string via private PrepareWrite, but it's missing somehow. Now it shouldn't be.
c30b284373