矢量迭代器不可解除 [英] Vector iterator not dereferencable

问题描述

我有一个抽象基类Shape，从中导出Circle和Rectangle，但是当我在VS 2005中执行以下代码时，我得到错误Debug断言失败。同时我没有在任何类中重载==运算符

I have an abstract base class called Shape from which both Circle and Rectangle are derived, but when I execute the following code in VS 2005 I get the error Debug assertion failed. At the same time I have not overloaded == operator in any class

表达式：Vector iterator not dereferencable，这是什么原因。

Expression:Vector iterator not dereferencable, what is the reason for this.

  vector<Shape*> s1;
  s1.push_back(new Circle(point(1,2),3));
  s1.push_back(new Circle(point(4,3),5));
  s1.push_back(new Rectangle(point(1,1),4,5));

  vector<Shape*> s2(s1);
  reverse(s1.begin(),s1.end());

  (*find(s1.begin(),s1.end(),new Circle(point(1,2),3)))->move(point(10,20));

推荐答案

简单：

• 查找失败，因为无法在向量中找到与之相比的Shape *


• 失败的find返回结束迭代器

为了像你想要的那样工作，你需要比较Shape，而不是Shape *

For it to work like you want, you do need to compare Shape, not Shape*

正如其他答案所指出的， boost :: ptr_vector 是实现此操作的简单方法。

As pointed out in other answers, boost::ptr_vector is an easy way to achieve this.

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