c++ - 在指向对象的指针上调用 delete [] 时出现 BLOCK_TYPE_VALID 错误

Question

此代码在 delete [] placard_ 上返回错误；打电话

void Protestor::destroy() { //Free's caller Protestor's dynamic memory
    delete [] placard_;
}

这段代码没有。

void Protestor::destroy() { //Free's caller Protestor's dynamic memory
    delete placard_;
}

这违背了我的类笔记，上面写着总是打电话

delete []

而不是

delete

这种行为的解释是什么？在什么情况下必须调用 'delete' 而不是 'delete []'？

这是 Protester 和 Sign 类的定义。

class Protester
{
  public:
    Protester(string name, string signSlogan, int signHeight, int signWidth,
              int rcmp_file = 0 );
    string getName() const;
    Sign getPlacard() const;
    void changePlacard( string newSlogan, int newHeight, int newWidth);
    void setRCMPfile(int RCMP_file);
    int getRCMPfile() const;

    //Big Three
    Protester(const Protester& other); //Copy Constructor
    ~Protester(); //Destructor
    Protester& operator= (const Protester& other); //Assignment Constructor


private:
    // name of the Protester
    string name_;

    // a sign the protester is wielding
    Sign* placard_;

    // the RCMP file number tracking this person (zero means no RCMP report)
    int rcmp_file_;

    //Big Three Helper Functions
    void copy(const Protester& other); //Performs Deep Copy of const Protester&
    void destroy(); //deletes [] placard_
                    //sounds better then cleanup, in my humblest of opinions.
};

class Sign
// a class representing information about signs/placards
{
public:
    // constructor to initialize sign text and dimensions
    Sign(string statement, int height, int width);

    // return sign text
    string getStatement() const;

    //return sign height
    int getHeight() const;

    //return sign width
    int getWidth() const;

    // change sign text
    void setStatement(string statement);

    // change sign dimensions
    void setSize(int height, int width);

private:
    // the text of the sign
    string statement_;

    // dimensions of the sign
    int height_;
    int width_;
};

Answer 1

This goes against my class notes, which state to ALWAYS call delete [] rather than delete

不，那是错误的。您必须配对调用 new 和 delete 以及调用 new[] 和 delete[]。

注意:但在现代 C++ 中，您不应该这样做。请改用 std::shared_ptr 或 std::unique_ptr。这通常是一个更安全的选择。对 new/new[] 的调用应该几乎总是包含在智能指针中，并且根本不需要 delete。很少有异常(exception)。