How do I determine if *exactly* one boolean is true, without type conversion?

Question

Given an arbitrary list of booleans, what is the most elegant way of determining that *exactly* one of them is true? The most obvious hack is type conversion: converting them to `0` for `false` and `1` for `true` and then summing them, and returning `sum == 1`. I'd like to know if there is a way to do this *without* converting them to ints, **actually using boolean logic**. *(This seems like it should be trivial, idk, long week)* **Edit:** In case it wasn't obvious, this is more of a code-golf / theoretical question. I'm not fussed about using type conversion / int addition in PROD code, I'm just interested if there is way of doing it without that. **Edit2:** Sorry folks it's a long week and I'm not explaining myself well. Let me try this: In boolean logic, ANDing a collection of booleans is true if all of the booleans are true, ORing the collection is true if least one of them is true. Is there a logical construct that will be true if exactly one boolean is true? XOR is this for a collection of two booleans for example, but any more than that and it falls over.

Answer 1

You have a list of N boolean variables hopefully in an array....

N is a positive integer

boolean boolArray[N];

int hitCount=0;

for (iLoop=0; iLoop<N; iLoop++)

{

if (boolArray[iLoop]) { hitCount++; }

if (hitCount>1)

{

break;

}

}

if (hitCount==1)

{

// output that there is only one true boolean var in the array

}

else

{

// putput there is more than one true boolean var in the array

}