二级指针

typedef struct
{
	uint8_t data1;
	uint8_t data2;
}data_type;
data_type data_instance =
{
	10,
	20
};
data_type *data;
void ptr_func(data_type **data_ptr)
{
	data = (data_type *)&data_instance;
	data->data1 = 30;

	*data_ptr = data;
}
int main(void)
{
	data_type *handle;
	ptr_func(&handle);
	handle->data1 = 50;
	handle->data2 = 100;
}

　　常用于动态内存申请