C语言结构体的字节对齐

Test Code:

 #include <iostream>
 #include <cstring>

 using namespace std;

 struct A{
     int a;
     short b;
     char d;
     char e[];
 };

 struct B{
     int a;
     short b;
     char *c;
     char d;
     char e[];
 };

 int main(){

     cout<<sizeof(A)<<endl;
     cout<<sizeof(B)<<endl;
     cout<<"short "<<sizeof(short)<<endl;
     cout<<"int "<<sizeof(int)<<endl;
     cout<<"long "<<sizeof(long)<<endl;
     cout<<"char* "<<sizeof(char*)<<endl;

     return ;

 }

Output(Fedora 64bit):

20
32
short 2
int 4
long 8
char* 8