C++：std::copy 因访问冲突读取位置错误而失败

Question

我正在尝试从 class 复制我使用 std::copy C++ 函数创建的对象列表，但该函数崩溃了下一条错误消息：

Unhandled exception at 0x00007FFA91BAC570 (msvcr120.dll) in MyProject.exe: 0xC0000005: Access violation reading location 0xFFFFFFFFFFFFFFFF.

class 非常简单，我不知道什么会导致复制功能因此类错误而崩溃。 class 如下所示：

class XMLObjects
    {
    private:
        int id;
        string name;
        int leftUpCornerX;
        int leftUpCornerY;
        int rightDownCornerX;
        int rightDownCornerY;
        bool isFound; //it's true if this object was found in the OR file and in the GT file

public:
    XMLObjects(){}
    XMLObjects(int _id){ id = _id; }
    XMLObjects(int _id, string _name, int _leftUpCornerX, int _leftUpCornerY, int _rightDownCornerX, int _rightDownCornerY) { id = _id; name = _name; leftUpCornerX = _leftUpCornerX; leftUpCornerY = _leftUpCornerY; rightDownCornerX = _rightDownCornerX; rightDownCornerY = _rightDownCornerY; isFound = false; }
    ~XMLObjects(){}

    void setID(int _id){ id = _id; }
    void setName( string _name){ name=_name; }
    void setLeftUpCorner(int _leftUpCornerX, int _leftUpCornerY){ leftUpCornerX = _leftUpCornerX; leftUpCornerY = _leftUpCornerY; }
    void setRightDownCorner(int _rightDownCornerX, int _rightDownCornerY){ rightDownCornerX = _rightDownCornerX; rightDownCornerY = _rightDownCornerY; }
    void objectWasFound(){ isFound = true; }

    int getID(){ return id; }
    string getName(){ return name; }
    int getLeftUpCornerX(){ return leftUpCornerX; }
    int getLeftUpCornerY(){ return leftUpCornerY; }
    int getRightDownCornerX(){ return rightDownCornerX; }
    int getRightDownCornerY(){ return rightDownCornerY; }
    bool isObjectFound(){ return isFound; }
};

复制函数的调用如下所示：

list<XMLObjects> objects;
objects.push_front(obj1);
objects.push_front(obj2);
objects.push_front(obj3);
list<XMLObjects> NewObjectsList;
std::copy(objects.begin(), objects.end(), NewObjectsList.begin());

有人能帮忙吗？

Answer 1

std::copy 不会调整输出大小，因此您必须先调整容器大小或使用插入元素的特殊迭代器。

您可以使用以下代码。

std::copy(objects.begin(), objects.end(),
          std::inserter(NewObjectsList, NewObjectsList.end()));

如评论中所述，在您的情况下，您可以直接复制：

list<XMLObjects> NewObjectsList = objects;

C++：std::copy 因访问冲突读取位置错误而失败

C++: std::copy fails with access violation reading location error

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