灾难的 char *p = new char(4)

int _tmain(int argc, _TCHAR* argv[])
{
    char *p = new char(4);
    for (int i = 0; i < 4; i++)
    {
        p[i] = '0'+i;
    }
    delete[] p;
    p = NULL;

    return 0;
}

问题在于哪里?

看正确代码:

// char *p = new char(4);
char *p = new char[4];     

 

上述代码在类的 initialization-list 中尤为难找:

class SomeResource
{
public:
    SomeResource(const size_t n) : m_data(new char(n)){}    // Disaster! If you access m_data[1..n], 
                                                                // will causing undefined and obscure behavior.
                                                                // But vs 2010 compiler accept this 
                                                                // code without any warning.
                                                            // If you are under Debug mode in vs, there will 
                                                                // happen debug error just before programming exit.
    ~SomeResource(){    delete[] m_data;    }

private:
    // data
    char *m_data;
};