Rounding up a number to power of 2 < number

Using concept of "n&(n-1)" makes value = 0 if n is number with power of 2

#include <stdio.h>
int nextPwrOf2(int num)
{
     do
     {
 
         num++;
      }
      while (( num & num-1) != 0);
      return num;
 }

int main()
{
    int num=15;
    int nextPwr;
    nextPwr=nextPwrOf2(num);
    printf(" %d \n",nextPwr);
    return 0;
}