68 lines
1.6 KiB
C++
68 lines
1.6 KiB
C++
// main.cpp
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// objectSlicing
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#include <iostream>
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#include <vector>
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class Base{
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int _a;
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public:
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Base(){}
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virtual ~Base() {}
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Base(int aa) :_a(aa) {}
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int value_a();
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virtual int value_virtual();
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};
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int Base::value_a(){
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return _a;
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}
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int Base::value_virtual(){
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return _a;
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}
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class Derived : public Base {
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int _b;
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public:
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Derived(int x, int y) : Base(x), _b(y) {}
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virtual int value_virtual();
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};
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int Derived::value_virtual(){
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return _b;
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}
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void passByPointer(Base* bp){
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std::cout << "->value_a() = " << bp->value_a() << std::endl;
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std::cout << "->value_virtual() = " << bp->value_virtual() << std::endl;
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}
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void passByValue(Base b){
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std::cout << ".value_a() = " << b.value_a() << std::endl;
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std::cout << ".value_virtual() = " << b.value_virtual() << std::endl;
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}
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int main(int argc, const char * argv[]) {
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Derived d(1,2);
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std::cout << "d.value_virtual() = " << d.value_virtual() << std::endl;
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std::cout << std::endl << "pass pointer to base class " << std::endl;
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passByPointer(&d); // pass pointer to base class
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std::cout << std::endl << "pass by value (i.e. object of class Base) " << std::endl;
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passByValue(d); // pass Base-object by value -> object slicing: d is "transformed" int an object of class Base
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std::cout << std::endl << "store Derived objects in std::vector<Base>" << std::endl;
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std::vector<Base> v;
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v.push_back(d); // object slicing
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std::cout << ".value_a() = " << v[0].value_a() << std::endl;
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std::cout << ".value_virtual() = " << v[0].value_virtual() << std::endl;
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return 0;
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}
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