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  1. #include <map>
  2. #include <iostream>
  3.  
  4. template <
  5.     template <class K, class V, class C, class A> class mapImpl, 
  6.    class K, 
  7.    class V, 
  8.    class C=std::less<K>, 
  9.    class A=std::allocator<std::pair<const K, V> >
  10. >
  11. class value_with_iterator {
  12. public:
  13.    typedef typename mapImpl<const K,value_with_iterator,C,A>::iterator value_type;
  14.    value_type value;
  15. };
  16.  
  17. typedef std::map<size_t, value_with_iterator <std::map, size_t, size_t> > map_size_t_to_itself;
  18.  
  19. map_size_t_to_itself::iterator insert(map_size_t_to_itself& mapRef, size_t value)
  20. {
  21.    map_size_t_to_itself::value_type v(value, map_size_t_to_itself::mapped_type());
  22.    std::pair<map_size_t_to_itself::iterator, bool> res = mapRef.insert(v);
  23.    if (res.second) 
  24.      res.first->second.value = res.first;
  25.    return res.first;
  26. }
  27.  
  28. int main() {
  29.    map_size_t_to_itself mapObj;
  30.    map_size_t_to_itself::iterator i1 = insert(mapObj, 1);
  31.    map_size_t_to_itself::iterator i2 = insert(mapObj, 1);
  32.    map_size_t_to_itself::iterator i3 = insert(mapObj, 2);
  33.  
  34.    std::cout << i1->first << ": " << i1->second.value->first << std::endl;
  35.    std::cout << i2->first << ": " << i2->second.value->first << std::endl;
  36.    std::cout << i3->first << ": " << i3->second.value->first << std::endl;
  37. }
Success #stdin #stdout 0.01s 2812KB
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1: 1
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https://ideone.com/gnEhw
language:
C++ (gcc 8.3)
created:
12 years ago
visibility:
public

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