捋一捋 const char * p / char* const p / char const* p

const int *p1;
// p1 is a non-const pointer and points to a const int

int *const p2;
// p2 is a const pointer and points to a non-const int

const int *const p3;
// p3 is a const pointer and points to a const it

const int *pa1[10];
// pa1 is an array and contains 10 non-const pointer point to a const int

int *const pa2[10];
// pa2 is an array and contains 10 const pointer point to a non-const int

const int (* p4)[10];
// p4 is a non-const pointer and points to an array contains 10 const int

const int (*pf)();
// pf is a non-const pointer and points to a function which has no arguments and returns a const int

const int *p 与 int const *p 是一样的，即 *p 是常量；

而 int * const p 跟上面是不一样的，即 p 是常量；

我们知道引用只是一个别名，与变量共享存储空间，并且必须在定义的时候初始化，而且不能再成为别的变量的别名，这让我们想到什么呢，貌似跟  int * const p   的性质很像。

其实引用的底层就是用const指针来实现的

const int *p1;
// p1 is a non-const pointer and points to a const int

int *const p2;
// p2 is a const pointer and points to a non-const int

const int *const p3;
// p3 is a const pointer and points to a const it

const int *pa1[10];
// pa1 is an array and contains 10 non-const pointer point to a const int

int *const pa2[10];
// pa2 is an array and contains 10 const pointer point to a non-const int

const int (* p4)[10];
// p4 is a non-const pointer and points to an array contains 10 const int

const int (*pf)();
// pf is a non-const pointer and points to a function which has no arguments and returns a const int

const *char prt 指的是prt所指的地址上的内容，不能通过prt指针进行部分修改

char * const prt 指的是prt所指向的地址，不能修改

char  const  * prt 和 const *char prt 是一样的。