extern wxStaticText* add_label_to_sizer (wxGridBagSizer *, wxWindow *, wxString, bool, wxGBPosition, wxGBSpan span = wxDefaultSpan);
extern wxStaticText* add_label_to_sizer (wxGridBagSizer *, wxStaticText *, bool, wxGBPosition, wxGBSpan span = wxDefaultSpan);
extern std::string wx_to_std (wxString);
extern wxStaticText* add_label_to_sizer (wxGridBagSizer *, wxWindow *, wxString, bool, wxGBPosition, wxGBSpan span = wxDefaultSpan);
extern wxStaticText* add_label_to_sizer (wxGridBagSizer *, wxStaticText *, bool, wxGBPosition, wxGBSpan span = wxDefaultSpan);
extern std::string wx_to_std (wxString);