1. template <class InputIterator1, class InputIterator2, class OutputIterator>       
    2.  
     
  2. OutputIterator set_difference(InputIterator1 first1, InputIterator1 last1,        
    3.  
     
  3.                                 InputIterator2 first2, InputIterator2 last2,      
    4.  
     
  4.                                 OutputIterator result) {                          
    5.  
     
  5.     while(first1 != last1 && first2 != last2) {                                   
    6.  
     
  6.         if(*first1 < *first2) {                                                   
    7.  
     
  7.             *result = *first1;                                                    
    8.  
     
  8.             ++first1;                                                             
    9.  
     
  9.             ++result;                                                             
    10.  
     
  10.         } else if(*first2 < *first1) {                                            
    11.  
     
  11.             ++first2;                                                             
    12.  
     
  12.         } else {                                                                  
    13.  
     
  13.             ++first1;                                                             
    14.  
     
  14.             ++first2;                                                             
    15.  
     
  15.         }                                                                         
    16.  
     
  16.     }                                                                             
    17.  
     
  17.                                                                                   
    18.  
     
  18.     return copy(first1, last1, result);                      
    19.  
     
  19. } 
    20.  
    
 
    
 
 
    
 
    
     
     
  1. template <class InputIterator1, class InputIterator2, class OutputIterator>       
    2.  
     
  2. OutputIterator Set_symmetric_difference(InputIterator1 first1, InputIterator1 last1, 
    3.  
     
  3.                                         InputIterator2 first2, InputIterator2 last2, 
    4.  
     
  4.                                         OutputIterator result) {                  
    5.  
     
  5.     while(first1 != last1 && first2 != last2) {                                   
    6.  
     
  6.         if(*first1 < *first2) {                                                   
    7.  
     
  7.             *result = *first1;                                                    
    8.  
     
  8.             ++first1;                                                             
    9.  
     
  9.             ++result;                                                             
    10.  
     
  10.         } else if(*first2 < *first1) {                                            
    11.  
     
  11.             *result = *first2;                                                    
    12.  
     
  12.             ++first2;                                                             
    13.  
     
  13.             ++result;                              
    14.  
     
  14.         } else {                                                                  
    15.  
     
  15.             ++first1;                                                             
    16.  
     
  16.             ++first2;                                                             
    17.  
     
  17.         }                                                                         
    18.  
     
  18.     }                                                                             
    19.  
     
  19.                                                                                   
    20.  
     
  20.     return copy(first2, last2, copy(first1, last1, result));                      
    21.  
     
  21. } 
    22.