C ++迭代器问题 [英] C++ iterators problem

问题描述

我使用C ++的迭代器，我在这里有一些麻烦。它对表达式（这 - > _ Has_container（））在线interterter ++上说调试失败失败。
距离列表是向量<载体， DistanceNode>>。我做错了什么？

I'm working with iterators on C++ and I'm having some trouble here. It says "Debug Assertion Failed" on expression (this->_Has_container()) on line interIterator++. Distance list is a vector< vector< DistanceNode > >. What I'm I doing wrong?

vector< vector<DistanceNode> >::iterator externIterator = distanceList.begin();

   while (externIterator != distanceList.end()) {

    vector<DistanceNode>::iterator interIterator = externIterator->begin();

        while (interIterator != externIterator->end()){

          if (interIterator->getReference() == tmp){

     //remove element pointed by interIterator
     externIterator->erase(interIterator);             

          } // if
    interIterator++;
  } // while
  externIterator++;
   } // while      

推荐答案

c $ c> erase（）返回一个新的迭代器到下一个元素。到已擦除元素和到其后的元素的所有迭代器都将失效。你的循环忽略这个，并继续使用 interIterator 。

vector's erase() returns a new iterator to the next element. All iterators to the erased element and to elements after it become invalidated. Your loop ignores this, however, and continues to use interIterator.

你的代码应该看起来像这样： / p>

Your code should look something like this:

if (condition)
    interIterator = externIterator->erase(interIterator);
else
    ++interIterator;  // (generally better practice to use pre-increment)

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