02-01_next_higher_number_with_same_num_ones.go

package hd

// NextHigherNumberWithSameNumberOfOnes is useful in bitsets stored in integers to find next set of same cardinality.
// This function utilizes the theorem of Right-to-Left Computability.
func NextHigherNumberWithSameNumberOfOnes[T Unsigned](x T) T {
	// 								 x = xxx0 11111 00000
	smallest := x & -x            //     0000 00001 00000
	ripple := x + smallest        //     xxx1 00000 00000
	ones := x ^ ripple            //     0001 11111 00000
	ones = (ones >> 2) / smallest //     0000 00000 01111
	return ripple | ones          //     xxx1 00000 01111
}