Best practices for circular shift (rotate) operations in C++

Question

Left and right shift operators (<< and >>) are already available in C++. However, I couldn\'t find out how I could perform circular shift or rotate operations.

Answer 1

Assuming you want to shift right by L bits, and the input x is a number with N bits:

unsigned ror(unsigned x, int L, int N) 
{
    unsigned lsbs = x & ((1 << L) - 1);
    return (x >> L) | (lsbs << (N-L));
}