Why is the enumeration value from a multi dimensional array not equal to itself?

Question

Consider:

using System;

public class Test
{
    enum State : sbyte { OK = 0, BUG = -1 }

    static void Main(string[] args)
    {
        var s = new State[1,          


        

Answer 1

Let's consider OP's declaration:

enum State : sbyte { OK = 0, BUG = -1 }

Since the bug only occurs when BUG is negative (from -128 to -1) and State is an enum of signed byte I started to suppose that there were a cast issue somewhere.

If you run this:

Console.WriteLine((sbyte)s[0, 0]);
Console.WriteLine((sbyte)State.BUG);
Console.WriteLine(s[0, 0]);
unchecked
{
    Console.WriteLine((byte) State.BUG);
}

it will output :

255

-1

BUG

255

For a reason that I ignore^{(as of now)} s[0, 0] is cast to a byte before evaluation and that's why it claims that a == s[0,0] is false.