I would never put a complex expression with side effects inside a comparison anyway. I prefer simple code; if I have to have a complex expression, I'd evaluate it separately, then go on to do the comparison.
I hate those map-grep-map-fold-spindle-mutilate commands where everything is done in a single, incomprehensible line riddled with nested ternary operators and uncommented regexps. When the code breaks, there's no intermediate stages to check for correctness; there's just a mess of nested context and conditional return values that are supposed to work, but somehow don't.
Yes, I'm bitter. My boss got fired, and I have to maintain the code he left behind, most of it undocumented, and often attempting to solve problems we don't actually have, and may never encounter. Sometimes code that is probably never hit looks buggy; but it's hard to tell because of all the state and flags flying around.
It's done nothing to lessen my hatred for complex expressions where simple ones do the job. If you really need complexity, fine. If you don't, just do what's simple and obvious; don't waste someone else's time fixing your mistakes just because you thought it would be fun to be clever.