#include<iostream>
using namespace std;
struct box{
  char maker[40];
  float height;
  float width ;
  float length;
  float volume;
};
void show(box);
float tiji(box*);
int main()
{
    box a={"shandong",3,3,3,0};
   
   
    cout<<"the tiji is "<<tiji[&a]<<endl;
    show(a);
 return 0;
}
void show(box a )
{
 cout<<"the maker is "<<a.maker<<endl;
 cout<<"the height is "<<a.height <<endl;
 cout<<"the width is  "<<a.width <<endl;
 cout<<"the length is "<<a.length <<endl;
 cout<<"the volume is"<<a.volume <<endl;
}
float tiji(box* pa)
{
   pa->volume =pa->height *pa->length *pa->width ;
   return pa->volume ;
}

error C2107: 非法索引，不允许间接寻址
 cout<<"the tiji is "<<tiji[&a]<<endl;
这是运行不过去的地方  他说不允许间接寻址

函數用[]，你哪看來的？雖然説C++對某些函數可以這樣寫，但卻不是你現在這種情形。