c - 带有指向其他尚未声明的静态变量的指针的结构的静态初始化

Question

C语法问题。

我希望做出如下声明:

struct thingy {
    struct thingy* pointer;
}

static struct thingy thing1 = {
    .pointer = &thing2
};

static struct thingy thing2 = {
    .pointer = &thing1
};

我试过分别声明和初始化，如下所示:

struct thingy {
    struct thingy* pointer;
}

static struct thingy thing1;
static struct thingy thing2;

thing1 = {
    .pointer = &thing2
};

thing2 = {
    .pointer = &thing1
};

但是我不确定是否可以单独声明和初始化静态变量

有没有一种方法可以让它们在编译时相互指向对方？

Answer 1

你快到了。您需要先“前向声明”(实际上，这是一个暂定定义，感谢 AndreyT!)静态实例，然后使用所需的指针初始化它们的定义。

static struct thingy thing1;
static struct thingy thing2;

static struct thingy thing1 = {
    .pointer = &thing2
};

static struct thingy thing2 = {
    .pointer = &thing1
};

从技术上讲，您只需要前向声明暂时定义thing2。