std::basic_ifstream::swap
From cppreference.com
                    
                                        
                    < cpp | io | basic ifstream
                    
                                                            
                    
| void swap( basic_ifstream& other ); | (since C++11) | |
Exchanges the state of the stream with those of other. 
This is done by calling basic_istream<CharT, Traits>::swap(other) and rdbuf()->swap(other.rdbuf()).
| Contents | 
[edit] Parameters
| other | - | stream to exchange the state with | 
[edit] Return value
(none)
[edit] Example
| This section is incomplete Reason: no example | 
[edit] See also
| (C++11) | moves the file stream (public member function) | 
| (C++11) | swaps two basic_filebuf objects (public member function of std::basic_filebuf) |