Agreed, but I have seen one time (and only one time) where deleting a piece of code instead of leaving the comment generated a compiler bug that generated some weird code. Put comment in - good code, delete comment - bad code. It was really, really odd. Add an ignored assignment (a=1), good code. So, we left a comment with a "DO NOT DELETE". Next version of the compiler fixed the bug and we deleted the comment. Weirdest damn thing I ever saw.
Yes, but in my book, that's not commented out code, that's an (undocumented) compiler directive.
And I've done similar things with "undocumented compiler directives" for XSLT processors before. If you didn't leave the comments in then you got the dreaded "GregorSamsaException". I refer to it as "dreaded" because folks on our team dreaded it... the exception occurred at unpredictable times and who the hell was Gregor Samsa anyway, and what did that have to do with our Java application?
Turns out, Gregor is the main character of Kafka's "The Metamorphosis" and the exception was the brilliant idea of someone who wrote the XSLT transformer and probably thought it was cute. (It wasn't.) It was an internal exception in the transformer. (Get it? Metamorphosis? Transformer? Never mind.) It occurred when a certain buffer filled up, and the exact length of the XSLT input file affected that, so adding a few lines of commented-out content would make the error appear or disappear.
I wrote a lengthy essay explaining the above facts, and used commented-out excerpts of that essay as padding in the file. Yes, I was trying to be "cute" also, but I was too young to realize that was a bad idea.
Could have been. Although a comment or a printf kept the code working, and removing that line broke the line above it. Next compiler release fixed it. It was just odd and a lesson in compilers are not perfect.
