TiXmlString& TiXmlString::assign(const char* str, size_type len)

{

    size_type cap = capacity();

    if (len > cap || cap > *(len + ))

    {

        TiXmlString tmp;

        tmp.init(len);    //这里有new操作

        memcpy(tmp.start(), str, len);

        swap(tmp);

    }

    else

    {

        memmove(start(), str, len);

        set_size(len);

    }

    return *this;

}

////////////////////////////////

void swap (TiXmlString& other)

{

    Rep* r = rep_;

    rep_ = other.rep_;

    other.rep_ = r;

}

/////////////////////////////////

~TiXmlString ()

    {

        quit();    //里面有delete操作

    }