XOR of three values

Question

What is the simplest way to do a three-way exclusive OR?

In other words, I have three values, and I want a statement that evaluates to true IFF only one of

Answer 1

Here's a general implementation that fails quickly when more than one bool is found to be true.

Usage:

XOR(a, b, c);

Code:

public static bool XOR(params bool[] bools)
{
    return bools.Where(b => b).AssertCount(1);
}

public static bool AssertCount(this IEnumerable source, int countToAssert)
{
    int count = 0;
    foreach (var t in source)
    {
        if (++count > countToAssert) return false;
    }

    return count == countToAssert;
}