std::experimental::pmr::unsynchronized_pool_resource::do_is_equal
From cppreference.com
                    
                                        
                    
                    
                                                            
                    |   virtual bool do_is_equal(const memory_resource& other) const noexcept;  | 
(library fundamentals TS) | |
Compare *this with other for identity - memory allocated using a unsynchronized_pool_resource can only be deallocated using that same resource.
Return value
this == dynamic_cast<const unsynchronized_pool_resource*>(&other)
See also
|    [virtual]  | 
   compare for equality with another memory_resource (virtual protected member function of std::experimental::pmr::memory_resource)  |