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  1. #include <iostream>
  2. #include <exception>
  3.  
  4. class Foo 
  5. {
  6.     int i_;
  7.     int j_;
  8. public:
  9.     Foo(int i, int j) : i_(i), j_(j) {}
  10.  
  11.     void print_coords()
  12.     {
  13.         std::cout << this << " (" << i_ << ',' << j_ << ')' << std::endl;
  14.     }
  15. };
  16.  
  17. class Bar
  18. {
  19. public:
  20.     Foo *arr[5][5];  
  21. };
  22.  
  23. class Que
  24. {
  25. public:
  26.     void init(Bar *b)
  27.     {
  28.         for(int i=0; i<5; i++)
  29.             for(int j=0; j<5; j++)
  30.                 b->arr[i][j] = new Foo(i, j);
  31.     }
  32.  
  33.     void print(Bar *b, int i, int j)
  34.     {
  35.         try {
  36.             if(b->arr[i][j])
  37.                 b->arr[i][j]->print_coords();
  38.             else
  39.                throw 0;
  40.         } catch (int e) {
  41.             std::cout << &b->arr[i][j] << " points to null" << std::endl;
  42.         }
  43.     }
  44.  
  45.     void rem(Bar *b, int i, int j)
  46.     {
  47.         delete b->arr[i][j];
  48.         b->arr[i][j] = 0;
  49.     }
  50. };
  51.  
  52. int main()
  53. {
  54.     Bar *b = new Bar();
  55.     Que *q = new Que();
  56.  
  57.     q->init(b);
  58.     q->print(b, 2, 2);
  59.     q->rem(b, 2, 2);
  60.     q->print(b, 2, 2);
  61.  
  62.     return 0;
  63. }
Success #stdin #stdout 0.01s 2856KB
comments (?)
stdin
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Standard input is empty
stdout
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0x9e32140 (2,2)
0x9e32038 points to null
https://ideone.com/6zJZw
language:
C++ (gcc 8.3)
created:
13 years ago
visibility:
public

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