#define _GNU_SOURCE

 #include <string.h>

 void *mempcpy(void * dest , const void * src , size_t  n );


    #define _GNU_SOURCE 
 

  #include <wchar.h> 

    wchar_t *wmempcpy(wchar_t * dest , const wchar_t * src , size_t  n ); 

void *
combine (void *o1, size_t s1, void *o2, size_t s2) {
     void *result = malloc(s1 + s2);
     if (result != NULL)
          mempcpy(mempcpy(result, o1, s1), o2, s2);
     return result;
}