[bit.pow.two] Remove redundant Remarks specification #6820
Conversation
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[expr.const] p5.8 is restricted to core-language undefined behavior. Here, the remarks in the library section establish a special case that this particular library undefined behavior is on par with core language undefined behavior, as far as constant evaluation goes. |
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Right, not all violations of library preconditions are guaranteed to produce an error during constant evaluation, e.g. using In an ideal world, maybe all violations would be diagnosed. But removing this paragraph does not get us closer to that ideal, instead it removes a useful guarantee and so makes the standard worse. |
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@jensmaurer I have brought shame upon myself. Thanks for clearing up my misconception. |
This paragraph is useless and should be removed.
[structure.specifications] p3.3 already states that precondition violations are undefined behavior. Evaluations with undefined behavior are not core constant expressions as per [expr.const] p5.8.
It could be argued that this paragraph is not only pointless but also harmful because it suggests that the precondition violations don't generally disqualify expressions from being constant expressions, only in this case, and this is surely not intended.
Even if we read this paragraph as
... then what's the point of that? It just seems confusing.