送分了，快来看呀

[Developerljm]

struct _item{
...
...
}Item;

int Test(Item *p){
int x,y;
x=p;
y=p+1;
return y-x;
}

请问高人，Test函数的功能是什么呀？

[boyfling]

求结构_item的大小

[maojincxj]

求结构体_item的大小

[阿发伯]

相当sizeof(Item)

[Kevin__Li]

楼上两位兄弟，我下面的程序怎么不跟你们说的一样呀？
#include <stdio.h>

struct Student
{
char name[256];
int age;
};

int getSizeOfStudent(Student* stu)
{
//int x, y; //编译不过去
Student *x, *y;
x = stu;
y = stu+1;
return y-x;
}


int main(int argc, char* argv[])
{
Student stu = {"Test", 25};

printf("...%d\n", sizeof(Student));
printf("...%d\n", getSizeOfStudent(&stu));
printf("...%d\n", getSizeOfStudent(NULL));
return 0;
}

运行结果：
...260
...1
...1

注：我是在Tru64下用C++编译器编译，执行的！

[superman421]

这样子就是求_item的大小了
#include <stdio.h>

struct Student
{
char name[256];
int age;
};

int getSizeOfStudent(struct Student* stu)
{
int x, y;
x =(int) stu;
y =(int)( stu+1);
return y-x;
}


int main(int argc, char* argv[])
{
struct Student stu = {"Test", 25};

printf("...%d\n", sizeof(struct Student));
printf("...%d\n", getSizeOfStudent(&stu));
printf("...%d\n", getSizeOfStudent(NULL));
return 0;
}

[wangbing_eternal]

如下，可以通过编译。
#include <stdio.h>

struct Student
{
char name[256];
int age;
};

int getSizeOfStudent(struct Student* stu)
{
int x, y;//可以通过编译
x = stu;
y = stu+1;
return y-x;
}


int main(int argc, char* argv[])
{
struct Student stu = {"Test", 25};

printf("...%d\n", sizeof(struct Student));
printf("...%d\n", getSizeOfStudent(&stu));
printf("...%d\n", getSizeOfStudent(NULL));
return 0;
}