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编译器是否可以在模板元编程中识别递归问题？(Can compilers identify recursion issues in Template Meta programming?)
编译器是否可以在模板元编程中识别递归问题？(Can compilers identify recursion issues in Template Meta programming?)
在模板元编程中，如果使用结果无限循环错误地实现递归，语言编译器是否可以检测到它？ 或者编译器是否会遇到最终的堆栈溢出和崩溃？ 我敢打赌，编译器无法检测到这一点，因为这样做会违反暂停问题的不可预测性。
我的结论是否正确？ 当然我可以用一段代码来试试这个，但我想在这种情况下听到更多合格的思考。
编辑：谢谢你们，我得到了一个普遍的想法，即我对tmp的计算理论方面的推论没有错。 我也明白，编译器实现可以有任意的递归深度限制（当然我重申我可以测试第二部分，但它只是我的一个方面）。
In Template Meta Programming if a recursion is wrongly implemented with a resulting infinite loop, can the language compiler detect it? Or will the compiler just encounter an eventual stack overflow and crashe? My bet would be that compiler cannot detect this because doing so would violate the undecideability of the halting problem.
Am I right with the conclusion? Of course I could try this out with a piece of code, but I would like to hear more qualified thinking in this case.
Edit : Thanks guys, I get a general idea that my inference on the computation theory aspect of tmp was not wrong. I also understand that compiler implementations can have arbitrary recursion depth limits(Of course I reiterate that I could have tested this second part, but it was only my side-point).
原文：https://stackoverflow.com/questions/10873179
更新时间：2023-10-14 06:10
最满意答案
每个班次都有一个
hasMany，因此你不能在集合上调用shift_workers()。你要循环，如下所示：
foreach ($event->shifts as $shift) { $shift->shift_workers()->saveMany($workers); }Each shift has a
hasMany, so you can't callshift_workers()on a collection.You've to loop, like below:
foreach ($event->shifts as $shift) { $shift->shift_workers()->saveMany($workers); }
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