const 变量修饰 研究

#include<stdio.h>
#include<iostream>
using namespace std;

struct A
{
    const int value_const() const{return ;}
    const int value(){return ;}
};

int main()
{
    A* const a1=new A;   //const 修饰指针本身
    const A*a2=a2=new A; //const 修饰指针 指向内容不可变;本身可变

    //a1=new A; //wrong
    //a1=new A; //wrong
    a2=new A;
    a2=new A;
    cout<<a1->value()<<endl;
    cout<<a1->value_const()<<endl;
    //cout<<a2->value()<<endl;//wrong
    cout<<a2->value_const()<<endl;//Must with const

    return ;
}