45 lines
1.0 KiB
C++
45 lines
1.0 KiB
C++
/**
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* @file virtual_inline.cpp
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* @brief 通常类成员函数都会被编译器考虑是否进行内联。
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* 但通过基类指针或者引用调用的虚函数必定不能被内联。
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* 当然，实体对象调用虚函数或者静态调用时可以被内联，虚析构函数的静态调用也一定会被内联展开。
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* @author 光城
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* @version v1
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* @date 2019-07-24
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*/
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#include <iostream>
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using namespace std;
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class Base
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{
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public:
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virtual void who()
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{
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cout << "I am Base\n";
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}
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};
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class Derived: public Base
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{
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public:
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void who()
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{
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cout << "I am Derived\n";
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}
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};
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int main()
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{
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// note here virtual function who() is called through
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// object of the class (it will be resolved at compile
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// time) so it can be inlined.
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Base b;
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b.who();
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// Here virtual function is called through pointer,
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// so it cannot be inlined
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Base *ptr = new Derived();
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ptr->who();
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return 0;
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}
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