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  1. #include <iostream>
  2.  
  3. class Example {
  4.     private:
  5.         int a;
  6.         // lots of important variables that live on the heap
  7.     public:
  8.         int getA() { return a; }
  9.  
  10.         Example(Example& other) {
  11.         	std::cout << "Example copy constructor" << std::endl;
  12.         	a = other.a;
  13.         }
  14.  
  15.         Example(int a_local) {
  16.             a = a_local;
  17.             std::cout << "Example constructor" << std::endl;
  18.             /* allocating memory, etc. ... */
  19.         }
  20. };
  21.  
  22. class Child: public Example {
  23.     // we get `a` and `getA()` from example
  24.     private:
  25.         int b;
  26.     public:
  27.     	Child(int a2, int b2) : Example(a2) {
  28.     		std::cout << "Child constructor" << std::endl;
  29.     		b = b2;
  30.     	}
  31.  
  32.         int getB() { return b; }
  33.         int getAplusB() { return getA() + b; } // we can't use `a` directly since it's private
  34. };
  35.  
  36. int main() {
  37. 	Child c(1, 5);
  38. 	std::cout << c.getA() << std::endl;
  39. 	std::cout << c.getB() << std::endl;
  40. 	std::cout << c.getAplusB() << "\n" << std::endl;
  41.  
  42. 	Example& e = dynamic_cast<Example&>(c);
  43. 	// Example& e = c;
  44. 	// Example e = c;
  45. 	std::cout << e.getA() << "\n" << std::endl;
  46.  
  47. 	// Example e2(10);
  48. 	// Child c2 = dynamic_cast<Child&>(e2);
  49. }
Success #stdin #stdout 0s 15232KB
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Standard input is empty
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Example constructor
Child constructor
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https://ideone.com/ETJ0uh
language:
C++14 (gcc 8.3)
created:
7 years ago
visibility:
secret

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