C# – way to perform a circular bit shift in C#


I know that the following is true

int i = 17; //binary 10001
int j = i << 1; //decimal 34, binary 100010

But, if you shift too far, the bits fall off the end. Where this happens is a matter of the size of integer you are working with.

Is there a way to perform a shift so that the bits rotate around to the other side? I'm looking for a single operation, not a for loop.

Best Solution

If you know the size of type, you could do something like:

uint i = 17;
uint j = i << 1 | i >> 31;

... which would perform a circular shift of a 32 bit value.

As a generalization to circular shift left n bits, on a b bit variable:

/*some unsigned numeric type*/ input = 17;
var result = input  << n | input  >> (b - n);

@The comment, it appears that C# does treat the high bit of signed values differently. I found some info on this here. I also changed the example to use a uint.