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  1. #include <iostream>
  2. #include <memory>
  3. #include <stdexcept>
  4. using namespace std;
  5.  
  6. class S
  7. {
  8. private:
  9. 	int* data;
  10.     bool is_const;
  11. public:
  12.     S() : data(new int[10]), is_const(false) { data[1] = 42; }
  13.     S(const S& other) : data(other.data), is_const(true) {}
  14.     S(S& other) : data(other.data), is_const(false) {}
  15.  
  16.     int& operator()(size_t i)
  17.     {
  18.     	if (is_const)
  19.     		throw std::logic_error("non-const operation attempted");
  20.         return data[i];
  21.     }
  22.  
  23.     const int& operator()(size_t i) const
  24.     {
  25.         return data[i];
  26.     }
  27. };
  28.  
  29. int main() {
  30. 	try
  31. 	{
  32. 	    const S a; // Allocates memory
  33.     	const S c(a);
  34.     	cout << c(1) << endl;
  35.     	S b(a); // Also points to memory allocated for a
  36.     	b(1) = 3; // Generates an exception
  37.     	cout << b(1) << endl; // never reached
  38. 	}
  39. 	catch (exception &e)
  40. 	{
  41. 		cout << "exception: " << e.what() << endl;
  42. 	}
  43. 	return 0;
  44. }
Success #stdin #stdout 0s 16064KB
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stdin
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Standard input is empty
stdout
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42
exception: non-const operation attempted
https://ideone.com/SFN89M
language:
C++14 (gcc 8.3)
created:
6 years ago
visibility:
public

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