2014-04-26 10:52:28 -04:00
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can't happen
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2014-04-26 11:54:15 -04:00
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The traditional program comment for code executed under a condition that
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should never be true, for example a file size computed as negative. Often,
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such a condition being true indicates data corruption or a faulty algorithm;
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it is almost always handled by emitting a fatal error message and
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terminating or crashing, since there is little else that can be done. Some
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case variant of is also often the text emitted if the impossible error
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actually happens! Although events are genuinely infrequent in production
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code, programmers wise enough to check for them habitually are often
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surprised at how frequently they are triggered during development and how
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many headaches checking for them turns out to head off. See also firewall
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code (sense 2).
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