std::chrono::operator<< (std::chrono::sys_info)
From cppreference.com
                    
                                        
                    
                    
                                                            
                    |   Defined in header  <chrono>
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|   template< class CharT, class Traits > std::basic_ostream<CharT, Traits>& operator<<( std::basic_ostream<CharT, Traits>& os,  | 
(since C++20) | |
Inserts a textual representation of r into os. The exact format is unspecified.
Return value
os