C++常量指针与常量数据

int demo = 0;
int * const p = &demo;

int demo = 0;
const int * p = &demo;

int demo = 0,test = 1;
//常量指针
int * const p = &demo;
*p = 1; //right!
p = &test; //wrong!

int demo = 0,test = 1;
//常量数据
const int *p = &demo;
*p = 1;//wrong!
p = &test; //right!

int demo = 0,test = 1;
const int * const p = &demo;
*p = 1;//wrong!
p = &test; //wrong!