编译器对齐问题

#include
#if defined(_ALIGN_PACKED_)
#pragma options align=packed
#else
#pragma pack(1)
#endif

typedef struct
{
    char      s1;
    unsigned short int s2;
    unsigned int s3;
}AFAALIGN,*PAFAALIGN;

 

int main()
{
    printf("sizeof(AFAALIGN) is %d\n",sizeof(AFAALIGN) );
    printf("sizeof(unsigned short int) %d\n",sizeof(unsigned short int));
   
    getchar();
    return 0;
}

如果没定义宏_ALIGN_PACKED_，sizeof(AFAALIGN)的值为7，否则结果为8。