将空指针转换为结构体

I started feeling comfortable with C and then I ran into type casting. If I have the following defined in an *.h file

我开始对C很满意，然后我就开始打字了。如果我在*中定义了以下内容。h文件

struct data {
    int value;
    char *label;
};

and this in another *.h file

这个在另一个*。h文件

# define TYPE      void*

How do I cast the void pointer to the struct so that I can use a variable "TYPE val" that's passed into functions? For example, if I want to utilize the value that TYPE val points to, how do I cast it so that I can pass that value to another functions?

如何将void指针转换为struct，以便使用传递给函数的变量"TYPE val" ?例如，如果我想要利用val类型所指向的值，我该如何对它进行转换，以便能够将该值传递给另一个函数?

2 个解决方案

#1

(struct data*)pointer

will cast a pointer to void to a pointer to struct data.

将一个指向void的指针转换为指向struct数据的指针。

#2

-1

Typecasting void pointer to a struct can be done in following

类型转换空指针到结构体可以在下面完成

void *vptr;
typedef struct data
{
   /* members */
}tdata;

for this we can typecast to struct lets say u want to send this vptr as structure variable to some function

为此，我们可以将这个结构类型转换为struct假设u要将这个vptr作为结构变量发送给某个函数

then

然后

void function (tdata *);
main ()
{
    /* here is your function which needs structure pointer 
       type casting void pointer to struct */

    function((tdata *) vptr);
}

Note: we can typecast void pointer to any type, thats the main purpose of void pointers.

注意:我们可以将void指针类型转换为任何类型，这是void指针的主要目的。

#1

(struct data*)pointer