c - `const`的特殊用法

Question

这个问题已经有答案了:

What is the difference between const int*, const int * const, and int const *? (23 个回答)

已关闭 5 年前。

我已经了解了(如果我错了，请纠正我)很多关于关键字 const 的知识。我了解到，如果你像这样从右向左阅读，那就很容易了:

int a = 0;                 // `a` is an integer. Its value is initialized with zero
const int b = 0;           // `b` is an integer which is constant. Its value is set to zero
int * c = &a;              // `c` is a pointer to an int. `c` is pointing to `a`.
int * const d= &a;         // `d` is a constant pointer to an int. It is pointing to `a`.
const int * e = &a;        // `e` is a pointer to an int which is constant. It is pointing to `a`.
int * const f = &a;        // `f` is a constant pointer to an int. It is pointing to `a`.
const int * const g = &b;  // `g` is a constant pointer to a constant integer. It is pointing to `b`.

但是这是怎么回事:

int const * h;

是h指向常量 int 的指针？如果是，与e有什么不同？ ？

这是什么:

int const i;

是i这与 b 类型相同？

Answer 1

const 限定符可以自由放置在类型关键字之前或之后，只要它们之间没有 * 符号即可。

因此以下内容是等效的:

int const *h;
const int *h;

这些是:

int const i;
const int i;

但这些不是:

int * const p;
const int *p;