This is my solution based on the “best bit counting method” from http://graphics.stanford.edu/~seander/bithacks.html#CountBitsSetParallel public static Int32 GetCardinality(BitArray bitArray) { Int32[] ints = new Int32[(bitArray.Count >> 5) + 1]; bitArray.CopyTo(ints, 0); Int32 count = 0; // fix for not truncated bits in last integer that may have been set to true with SetAll() ints[ints.Length – 1] … Read more
This simple snippet shows a manual way to do it. The value of bitArray[0] is overwritten: //… bitArray is the BitArray instance for (int i = 1; i < bitArray.Count; i++) { bitArray[i – 1] = bitArray[i]; } bitArray[bitArray.Count – 1] = false // or true, whatever you want to shift in Making this an … Read more
I think you’ve got yourself confused between arrays and numbers, specifically what it means to manipulate binary numbers. I’ll go about this by example. Say you have a number of error messages and you want to return them in a return value from a function. Now, you might label your errors 1,2,3,4… which makes sense … Read more
@Jonathon Reinhart, your benchmark is unfortunately inconclusive. It does not take into account the effects of possible lazy-loading, caching and/or prefetching (by the CPU, the host OS and/or the .NET runtime). Shuffle the order of the tests (or call the test methods multiple times) and you might notice different time measurments. I did your original … Read more
If I am not too late, this page gives awesome explanation with examples. An array of int can be used to deal with array of bits. Assuming size of int to be 4 bytes, when we talk about an int, we are dealing with 32 bits. Say we have int A[10], means we are working … Read more
This should work: byte ConvertToByte(BitArray bits) { if (bits.Count != 8) { throw new ArgumentException(“bits”); } byte[] bytes = new byte[1]; bits.CopyTo(bytes, 0); return bytes[0]; }
As selected answer says you can use findAndModify to generate sequential IDs. But I strongly disagree with opinion that you should not do that. It all depends on your business needs. Having 12-byte ID may be very resource consuming and cause significant scalability issues in future. I have detailed answer here.
If you mainly want to be able to name your bit fields and easily manipulate them, e.g. to work with flags represented as single bits in a communications protocol, then you can use the standard Structure and Union features of ctypes, as described at How Do I Properly Declare a ctype Structure + Union in … Read more