std::future_error::operator=
From cppreference.com
                    
                                        
                    < cpp | thread | future error
                    
                                                            
                    |   future_error& operator=( const future_error& other ) noexcept;  | 
(since C++11) | |
Assigns the contents with those of other. If *this and other both have dynamic type std::future_error then std::strcmp(what(), other.what()) == 0 after assignment.
Parameters
| other | - |  another future_error object to assign with
 | 
Return value
*this
Example
| This section is incomplete Reason: no example  |