C does have a logical XOR, it's the `!=` operator. Unlike other logical operators, it requires the arguments to be normalized to a single truth value. It plays nicely with C's convert-to-boolean operator `!!`.

^ ?

That's bitwise, not logical.

That's bitwise xor

I once failed a a test at a job interview because I hadn't realised that (even after having been programming for twenty years).

No need for the second !: !foo != !bar

True, but you might confuse people if you use a nonstandard construct like this.

Topic starts at 37:18

DMR was remarkably kind, helpful and accessible. As an undergrad in the mid 80s I read about 'the first' port of Unix (v6) to something other than a PDP-11, the Interdata 8/32. On a whim, I sent an email to [email protected] (might have even been back as far as research!dmr or [email protected]) asking if there was more info about the architecture as 1) no google and 2) nothing in the uni library. A couple of days later he responded and asked for my (physical) address. A few weeks later, a copy of the instruction set summary manual showed up in my (physical) mailbox. It's IBM 360-ish. Still have it.

> Faulkner said it was because you couldn't short circuit it

I don't get it. Why is that an impediment to adding an operator? Can some one elaborate?

There wouldn't be any advantage to adding a boolean exclusive or operator, unlike with || and &&.