Counting the number of flags set on an enumeration

Question

I\'m sure there must be a much better way of doing this. I\'m trying to do a count operation on a Flags enum. Before I was itterating over all the possible values and counting t

Answer 1

If you're targeting .NET Core 3.0 or above, you can use BitOperations.PopCount(), it operates in uint or ulong and returns the number of 1 bits.

If your CPU supports SSE4, it'll use the POPCNT CPU instruction, otherwise it'll use a software fallback.

public static int Count(Skills skillsToCount)
{
   return BitOperations.PopCount((ulong)skillsToCount);
}