typedef struct min_index
{
    using uint8 = typename unsigned char;
	uint8 _val : 2;  // 内部数据占用2字节空间

	min_index()
		: _val(0) {}
	min_index(uint8 val)
		: _val(val) {}

    // 重载数据类型
	operator uint8()
	{ return _val; }
	operator bool()
	{ return _val; }

	min_index &operator=(uint8 val)
	{ _val = val; }

    // 重载 == 和 !=
	bool operator==(uint8 val)
	{ return _val == val; }
	bool operator!=(uint8 val)
	{ return _val != val; }

    // 重载后置++
	min_index operator++(int)
	{ ++_val; return _val; }
    // 重载前置++
	min_index &operator++()
	{ ++_val; return *this; }

    // 重载后置--
	min_index operator--(int)
	{ --_val; return _val; }
    // 重载前置--
	min_index &operator--()
	{ --_val; return *this; }
}min_index;