基类中的this指针，指示其派生类吗？

#include <iostream> using namespace std; class baseA { public: int i; baseA(); //~baseA(); virtual void show() { cout << "this is baseA class show() /n";} }; class baseB { float f_pi; long long ll_sum; public: int i; baseB(); //~baseB(); virtual void show() { cout << "this is baseB class show() /n";} }; class derived : public baseA,baseB { public: int i; derived() ; //~derived(); virtual void show() { cout << "this is derived class show() /n";} }; class derived2 : public derived { public: int i; derived2() ; //~derived(); virtual void show() { cout << "this is derived2 class show() /n";} }; baseA *pA; baseB *pB; baseA::baseA() { i=1; cout << "in baseA/n"; pA=this; this->show(); }; baseB::baseB() { i=2; f_pi = 3.14f; ll_sum = 1234567ll; cout << "in baseB/n"; pB=this; this->show(); }; derived::derived() : baseA(),baseB() { i =2; cout << "in derived /n"; this->show(); }; derived2::derived2() : derived() { i =2; cout << "in derived2 /n"; this->show(); }; derived od; derived2 oe; int main(int argc, char * argv[]) { cout << "in main() /n/n od.show()/n"; od.show(); cout << "n/n oe.show()/n"; oe.show(); cout << "/npA->show() /n"; pA->show(); cout << "/npB->show() /n"; //why? pB->show(); cout << "/nsizeof(*pA):" << sizeof(*pA) << "/n"; cout << "sizeof(*pB):" << sizeof(*pB) << "/n"; cout << "sizeof(od):" << sizeof(od) << "/n"; cout << "sizeof(oe):" << sizeof(oe) << "/n/n"; //((derived *) pA)->show(); //(reinterpret_cast<derived *>(pB))->show(); system("pause"); return 0; }

in baseA
this is baseA class show()
in baseB
this is baseB class show()
in derived
this is derived class show()
in baseA
this is baseA class show()
in baseB
this is baseB class show()
in derived
this is derived class show()
in derived2
this is derived2 class show()
in main()

 od.show()
this is derived class show()
n
 oe.show()
this is derived2 class show()

pA->show()
this is derived2 class show()//<<<<<<<<<<<

pB->show()
this is derived2 class show()//<<<<<<<<<<<

sizeof(*pA):8
sizeof(*pB):32
sizeof(od):48
sizeof(oe):56

请按任意键继续. . .

 

结论：在main之中，题目是正确的。基类的this指针，的确在调用函数的时候，“改向”到了派生类上了。叛变了，傍大款了。