Logical XOR operator in C++?

user_127578 0
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Is there such a thing? It is the first time I encountered a practical need for it, but I don't see one listed in Stroustrup. I intend to write:

// Detect when exactly one of A,B is equal to five.
return (A==5) ^^ (B==5);

But there is no ^^ operator. Can I use the bitwise ^ here and get the right answer (regardless of machine representation of true and false)? I never mix & and &&, or | and ||, so I hesitate to do that with ^ and ^^.

I'd be more comfortable writing my own bool XOR(bool,bool) function instead.

logical-operators operators c++
11 Answers

(A || B) && !(A && B)

The first part is A OR B, which is the Inclusive OR; the second part is, NOT A AND B. Together you get A or B, but not both A and B.

This will provide the XOR proved in the truth table below.

|-----|-----|-----------|
|  A  |  B  |  A XOR B  |
|-----|-----|-----------|
|  T  |  T  |   False   |
|-----|-----|-----------|
|  T  |  F  |   True    |
|-----|-----|-----------|
|  F  |  T  |   True    |
|-----|-----|-----------|
|  F  |  F  |   False   |
|-----|-----|-----------|
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