language: C++ 4.7.2 (gcc-4.7.2)
date: 851 days 18 hours ago
link:
visibility: public 
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#include <iostream>
 
class empty
{
};
 
class empty_one : public empty {};
class empty_two : public empty {};
 
class non_empty
    : public empty_one
    , public empty_two
{
};
 
int main()
{
    std::cout << "sizeof(empty): " << sizeof(empty) << std::endl;
    std::cout << "sizeof(empty_one): " << sizeof(empty_one) << std::endl;
    std::cout << "sizeof(empty_two): " << sizeof(empty_two) << std::endl;
    std::cout << "sizeof(non_empty): " << sizeof(non_empty) << std::endl;
 
    std::cout << std::endl;
 
    non_empty a[2];
 
    void* pe10 = static_cast<empty*>(static_cast<empty_one*>(&a[0]));
    void* pe20 = static_cast<empty*>(static_cast<empty_two*>(&a[0]));
    std::cout << "address of non_empty[0]: " << &a[0] << std::endl;
    std::cout << "address of empty of empty_one: " << pe10 << std::endl;
    std::cout << "address of empty of empty_two: " << pe20 << std::endl;
 
    std::cout << std::endl;
 
    void* pe11 = static_cast<empty*>(static_cast<empty_one*>(&a[1]));
    void* pe21 = static_cast<empty*>(static_cast<empty_two*>(&a[1]));
    std::cout << "address of non_empty[1]: " << &a[1] << std::endl;
    std::cout << "address of empty of empty_one: " << pe11 << std::endl;
    std::cout << "address of empty of empty_two: " << pe21 << std::endl;
}