第六章习题的一些疑问 about cppprimer HOT 8 CLOSED

what's the meaning of "preexited"?

preexited: pre + exited --- exist at or from an earlier time.
such as local objects. and example of the book:

const string &manip()
{
    string ret;
    // transform ret in some way
    if (!ret.empty())
        return ret;  // WRONG: returning a reference to a local object!
    else
        return "Empty"; // WRONG: "Empty" is a local temporary string
}

Tip
One good way to ensure that the return is safe is to ask: To what preexisting
object is the reference referring?
---- Never Return a Reference or Pointer to a Local Object (6.3.2. Functions That Return a Value)

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it will crash. (Windows + vs2013) I want to know why

loops endlessly.
check this: http://stackoverflow.com/questions/20184299/how-to-understand-and-fix-the-segmentation-fault-in-this-code

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Function func can take 0 parameter

check this question: Mooophy/Cpp-Primer#129 , @Mooophy give very clear explanation.

and check this question: http://stackoverflow.com/questions/26530659/confused-about-array-parameters

You may have more better understanding.

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@Ocxs is a good learner. 👍

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@pezy @Mooophy 在SO上问的问题，根据被采纳的答案说的，我将我的理解说一下，您看对不对（英文不是太好）由于static 定义的迭代器it，导致其只会被初始化一次，直到程序结束才会释放。所以在第一次调用vector_print(_v);没问题，但是由于while(cin >> s),s被push_back到_v，然后就会导致迭代器失效，再次调用vector_print(_v);，由于it是用static声明的，他只能被初始化一次，所以这叫导致这时候的it实际上指的就不是新加元素的_v，解引用it实际是解引用尾后迭代器，这是非法的在C++语法中？不知道理解的对不对？
Thank you for your explanation ! I got it .(BTW,I had some questions to invite you to answer in segmentfault ,if you have free time ,please help me .Thanks in advance . 👍

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@Mooophy Thanks ！ I will continue to work hard！ 😄

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不知道理解的对不对？

对的。就是这样。和你使用 const vector<T> _v 导致崩溃，其实大同小异。参数不加引用，第二次递归进入该函数的时候，此_v早已不是彼_v了。

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@pezy Thanks a lot! 😄

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