C++ keywords: export
From cppreference.com
                    
                                        
                    
                    
                                                            
                    [edit] Usage
| Used to mark a template definition exported, which allows the same template to be declared, but not defined, in other translation units. | (until C++11) | 
| The keyword is unused and reserved. | (since C++11) | 
| Marks a declaration, a group of declarations, or another module as exported by the current module. | (modules TS) |