#include "stdafx.h"

#pragma pack(1)
struct S
{
	char a;
	int b;
};

int _tmain(int argc, _TCHAR* argv[])
{
	S a;
	S b;
	printf("sizeof(a)=%i sizeof(b)=%i\n", sizeof(a), sizeof(b));
	return 0;
}

===================================

sizeof(a)=5 sizeof(b)=5