This quiz is a little bit different than some of my others.  Here is System.String.GetHashCode

public override unsafe int GetHashCode()
{
      fixed (char* text1 = ((char*) this))
      {
            char* chPtr1 = text1;
            int num1 = 0x15051505;
            int num2 = num1;
            int* numPtr1 = (int*) chPtr1;
            for (int num3 = this.Length; num3 > 0; num3 -= 4)
            {
                  num1 = (((num1 << 5) + num1) + (num1 >> 0x1b)) ^ numPtr1[0];
                  if (num3 <= 2)
                  {
                        break;
                  }
                  num2 = (((num2 << 5) + num2) + (num2 >> 0x1b)) ^ numPtr1[1];
                  numPtr1 += 2;
            }
            return (num1 + (num2 * 0x5d588b65));
      }
}

It's a fine little hash function that's does pretty much the sorts of things you'd expect a hash function to do.

So now the quiz.  It's a bit of trivia but I'm going somewhere with it.

Can you tell me 5 implementations of GetHashCode in the framework that do things that you wouldn't expect a hashing function to do?