const char*, char const*, char*const的区别问题几乎是C++面试中每次都会有的题目。
事实上这个概念谁都有只是三种声明方式非常相似很容易记混。
Bjarne在他的The C++ Programming Language里面给出过一个助记的方法：
把一个声明从右向左读。
char * const cp; ( * 读成 pointer to
cp is a const pointer to char
const char * p;
p is a pointer to const char;
char const * p;
同上因为C++里面没有const*的运算符，所以const只能属于前面的类型。
C++标准规定，const关键字放在类型或变量名之前等价的。
const int n=5;
//same as belowint const m=10;
const int *p; //same as below
const (int) * pint const *q; // (int) const *p
char ** p1;
//pointer to pointer to char
const char **p2;
//pointer to pointer to const char
char * const * p3;
//pointer to const pointer to char
const char * const * p4;
//pointer to const pointer to const char
char ** const p5;
//const pointer to pointer to char
const char ** const p6;
//const pointer to pointer to const char
char * const * const p7;
//const pointer to const pointer to char
const char * const * const p8;
//const pointer to const pointer to const char
