请问这程式C语言改C++要怎么改???

#include <dos.h>
void write_CMOS(unsigned char index, unsigned char data)
{
outportb(0x70, index);
outportb(0x71, data);
}
void main()
{
/* write data 0FF Hex to index 6C Hex of CMOS RAM*/
write_CMOS(0x6C, 0xff);
/* read data from index 6B Hex of CMOS RAM*/
outportb(0x70, 0x6B);
inportb(0x71);
}