Position of rightmost set bit

reference: 

http://www.geeksforgeeks.org/position-of-rightmost-set-bit/

Problem Definition:

Write a one line C function to return position of first 1 from right to left, in binary representation of an Integer.

Solution:

Example 18(010010)

1. Take two's complement(i.e. -n) of the given no as all bits are reverted
except the first '1' from right to left (10111)

2  Do an bit-wise & with original no, this will return no with the
required one only (00010)

3  Take the log2 of the no, you will get position -1 (1)

4  Add 1 (2)

Code:

unsigned int getFirstSetBitPos(int n)
{
   return log2(n&-n)+1;//or log2(n & (n^(n-1)))+1
}