引用即是别名

看一下程序

#include <stdio.h>

typedef unsigned long int UINT4;

typedef struct {
  UINT4 state[4];
  UINT4 count[2];

} MY_T;

void initByPoint (MY_T *context)
{
  context->count[0] = context->count[1] = 0;
  /* Load magic initialization constants.
*/
  context->state[0] = 1;
  context->state[1] = 0xefcdab89;
  context->state[2] = 0x98badcfe;
  context->state[3] = 0x10325476;
}
void initByRef (MY_T &context)
{
  context.count[0] = context.count[1] = 0;
  /* Load magic initialization constants.
*/
  context.state[0] = 2;
  context.state[1] = 0xefcdab89;
  context.state[2] = 0x98badcfe;
  context.state[3] = 0x10325476;
}

void initByCommon (MY_T context)
{
  context.count[0] = context.count[1] = 0;
  /* Load magic initialization constants.
*/
  context.state[0] = 3;
  context.state[1] = 0xefcdab89;
  context.state[2] = 0x98badcfe;
  context.state[3] = 0x10325476;
}
int main(){

      MY_T t;
      MY_T &r=t;
      printf("t.state[0]=%lu\n",t.state[0]);
      printf("r.state[0]=%lu\n",r.state[0]);
      initByCommon(t);
      //initByCommon(r); 结果一样
      printf("t.state[0]=%lu\n",t.state[0]);
      printf("r.state[0]=%lu\n",r.state[0]);
      initByPoint(&t);
      //initByPoint(&r);结果一样
      printf("t.state[0]=%lu\n",t.state[0]);
      printf("r.state[0]=%lu\n",r.state[0]);
      initByRef(t);
      //initByRef(r); 结果一样
      printf("t.state[0]=%lu\n",t.state[0]);
      printf("r.state[0]=%lu\n",r.state[0]);
     
           

     
     
return 1;
}




t.state[0]=3218421528
r.state[0]=3218421528
t.state[0]=3218421528
r.state[0]=3218421528
t.state[0]=1
r.state[0]=1
t.state[0]=2
r.state[0]=2




elemtype& a1;
elemtype *a2;
elemtype a3;

fun1(elemtype& a);
fun2(elemtype *a);
fun3(elemtype a);

请问a1,a2,a3分别能做为fun1,fun2,fun3中哪几个函数的参数？

a1-f1，f3
a2-f2
a3-f1，f3