std::filesystem::status_known
From cppreference.com
                    
                                        
                    < cpp | filesystem
                    
                                                            
                    |   Defined in header  <filesystem>
  | 
||
|   bool status_known( std::filesystem::file_status s ) noexcept;  | 
(1) | (since C++17) | 
Checks if the given file status is known, Equivalent to s.type() != file_type::none.
Parameters
| s | - | file status to check | 
Return value
true if the given file status is a known file status.
Notes
Despite the name, the function checks for the file status of file_type::none (meaning an error occurred), not file_type::unknown (meaning file exists, but its type cannot be determined).
See also
|    (C++17)(C++17)  | 
  determines file attributes determines file attributes, checking the symlink target (function)  | 
|   status of the file designated by this directory entry symlink_status of the file designated by this directory entry (public member function of std::filesystem::directory_entry)  |