std::latch::max
From cppreference.com
                    
                                        
                    
                    
                                                            
                    |   static constexpr std::ptrdiff_t max() noexcept;  | 
(since C++20) | |
Returns the maximum value of the internal counter supported by the implementation.
Parameters
(none)
Return value
The maximum value of the internal counter supported by the implementation.