C + + Const this pointer

What does the const after const this pointer method list mean? Answer: You cannot modify member variables in a method

class Test{public:  void fun()const{    //data = 10;//编译不过，因为有const关键字，所以不可以修改this指针所指向的内容 }private:  int data;};

Note the point:

• It is possible to call the Const method in a non-const method
• It is possible to call the Const method in the Const method
• It is not possible to call a non-const method in a const method .

Reason: This pointer.

Because the this pointer in the non-const method has a const limit, it is not possible to give a non-const method A this pointer without a const restriction when calling a non-const method in a const method.

#include <iostream>using namespace std;class Test{public:  Test(int d = 0) : data(d){}  void a()const{    b();  }  //如果去掉方法b的const关键字，编译无法通过  void b()const{  }  ~Test(){}private:  int data;};int main(){  Test t(10);}

C + + Const this pointer