c++ 学习之const_cast 去掉const属性转换

c++ 学习之const_cast 去掉const属性转换

语法公式：
const_cast<目标类型>(标识符)
目标类型：指针或者引用

#include <iostream>

using namespace std;
struct A
{
    /* data */
    int data;
};


int main(int argc, char const *argv[])
{
    const A a = {2000};

    A a1 = const_cast<A&>(a);
    cout << a1.data << endl;
     
    A &a2 = const_cast<A&>(a);
    a2.data  = 20;
    cout << a2.data << endl;


    A *a3 = const_cast<A*>(&a);
    a3->data = 900;
    cout << a3->data << endl;


    const int x = 9;
    int &x1 = const_cast<int &>(x);
    x1 = 900;
    cout << x1 << endl;


    int *x2 = const_cast<int *> (&x);
    *x2 = 89;
    cout << *x2<<endl;

    return 0;
}

g++   main.cpp -o ./output/run
./output/run
2000
20
900
900
89