std::fpos_t
From cppreference.com
                    
                                        
                    
                    
                                                            
                    | Defined in header  <cstdio> | ||
| typedef /* implementation-defined */ fpos_t; | ||
std::fpos_t is a non-array complete object type, can be used to store (by std::fgetpos) and restore (by std::fsetpos) the position and multibyte parser state (if any) for a C stream.
The multibyte parser state of a wide-oriented C stream is represented by a std::mbstate_t object, whose value is stored as part of the value of a std::fpos_t object by std::fgetpos.
See also
| gets the file position indicator (function) | |
| moves the file position indicator to a specific location in a file (function) | |
| conversion state information necessary to iterate multibyte character strings (class) | |
| represents absolute position in a stream or a file (class template) |