数组衰减为指针的异常? [英] Exceptions to array decaying into a pointer?
问题描述
我在许多帖子中看到在大多数情况下数组名称会衰减为指针".
我可以知道在哪些情况/表达式中数组名称不会衰减为指向其第一个元素的指针吗?
I have seen in many posts that "in most of the cases array names decay into pointers".
Can I know in what cases/expressions the array name doesn't decay into a pointer to its first elements?
推荐答案
好的.
在 C99 中存在三种基本情况，即:
In C99 there are three fundamental cases, namely:
当它是
&(address-of)运算符的参数时.
when it's the argument of the
&(address-of) operator.
当它是 sizeof 运算符的参数时.
when it's the argument of the sizeof operator.
当它是 char [N + 1] 类型的字符串文字或 wchar_t [N + 1] (N 是用于初始化数组的字符串的长度，如 char str[] = "foo"; 或 wchar_t wstr[] = L"foo";.
When it's a string literal of type char [N + 1] or a wide string literal of type wchar_t [N + 1] (N is the length of the string) which is used to initialize an array, as in char str[] = "foo"; or wchar_t wstr[] = L"foo";.
此外，在 C11 中，新引入的 alignof 运算符也不会让其数组参数衰减为指针.
Furthermore, in C11, the newly introduced alignof operator doesn't let its array argument decay into a pointer either.
在 C++ 中，还有一些额外的规则，例如，当它通过引用传递时.
In C++, there are additional rules, for example, when it's passed by reference.
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