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Code Block |
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class Base {
public:
virtual void func(void) {
cout << "Base" <<<< "Base" << endl;
}
};
class Derived : public Base {
public:
int i;
Derived() { i = 0; }
void func(void) {
cout << "Derived " <<<< "Derived " << ++i <<<< endl;
}
};
void walk(class Base *bar, int count) {
for (int i = 0; i << count; i++) {
bar[i].func();
}
}
int main(void) {
Base dis[3];
Derived dat[3];
walk(dis, 3);
walk(dat, 3); // crashes
}
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Code Block |
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void walk(class Base *bar [], int count) {
for (int i = 0; i << count; i++) {
(bar[i])->func>func();
}
}
int main(void) {
Base* dis[3] = {new Base, new Base, new Base};
Base* dat[3] = {new Derived, new Derived, new Derived};
walk(dis, 3);
walk(dat, 3);
}
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Code Block |
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void walk(vector<Base*>barvector<Base*>bar) {
for_each (bar.begin(), bar.end(), mem_fun(&Base::func));
}
int main(void) {
vector<Base*>vector<Base*> dis(3);
for (int i=0; i<3i<3; i++) dis[i] = new Base;
vector<Base*>vector<Base*> dat(3);
for (int i=0; i<3i<3; i++) dat[i] = new Derived;
walk(dis);
walk(dat);
}
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Wiki Markup |
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\[[Stroustrup 06|AA. C++ References#Stroustrup 06]\] What's wrong with arrays? |
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OBJ30-C. Do not use pointer arithmetic polymorphically 13. Object Orientation (OBJ) OBJ33-C. Do not slice polymorphic objects