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  1.     struct A { virtual const char* fn() { return "A"; } };
  2.     struct B : public A { virtual const char* fn() { return "B"; } };
  3.  
  4.     #include <iostream>
  5.     #include <cstring>
  6.  
  7.     int main()
  8.     {
  9.         A* a = new A();
  10.         B* b = new B();
  11.         memcpy(a, b, sizeof(A));
  12.         std::cout << "sizeof A = " << sizeof(A)
  13.             << " a->fn(): " << a->fn() << '\n';
  14.     }       
  15.  
Success #stdin #stdout 0s 3228KB
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stdin
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Standard input is empty
stdout
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sizeof A = 4 a->fn(): B
https://ideone.com/G62Cn0
language:
C++14 (gcc 8.3)
created:
8 years ago
visibility:
secret

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