void CCoveragePointGeneration::getCoveragePoint(
            algo::CLocalSection& local_section, std::deque<algo::CChainCell>& up_deque_indent,
            std::deque<algo::CChainCell>& down_deque_indent, 
            std::deque<std::deque<algo::CChainCell>>& coverage_deque_up_split,
            std::deque<std::deque<algo::CChainCell>>& coverage_deque_down_split)
{
    .... //存在多次对大数据进行复制

    CCoverageData cover_data = local_section.getCoverageData();  //复制第一次
    algo::CChainMap chain_map = cover_data.getMap(); //复制第二次

    sparseCoveragePoint(cover_data, chain_map, coverage_deque_up_split, coverage_deque_down_split);

    cover_data.setMap(chain_map); //复制第三次
    local_section.setCoverageData(cover_data); //复制第四次
}

void CCoveragePointGeneration::sparseCoveragePoint(
        const CCoverageData& cover_data, algo::CChainMap& map,
        std::deque<std::deque<algo::CChainCell>>& coverage_up_deque,
        std::deque<std::deque<algo::CChainCell>>& coverage_down_deque) const //const 非常棒的限定,外部可以安心调用
{
  ....
}

class CCoverageData //本类所有成员超过480K大小(复制成本高昂)
{
    ....
    const algo::CChainMap& getMap() const //如果为const 方法一定要加该限定
    {
        return m_map;
    }

    algo::CChainMap& getMap() //添加非const方法和const方法重载
    {
        return m_map;
    }
};

class CLocalSection
{
    ....
    const CCoverageData& getCoverageData() const
    {
        return m_coverage_data;
    }

    CCoverageData& getCoverageData() //添加非const方法和const方法重载
    {
        return m_coverage_data;
    }
    //建议getCoverageData()  改名为 coverageData()
    //习惯使用: 获取参数直接名字(不用get修饰),设置时使用 set修饰

    /*  效率低下,且功能单一通过 普通getCoverageData()和 const方法配合能灵活且高效!
    void setMap( const algo::CChainMap& map)
    {
        m_map = map;
    }
    */
};


void CCoveragePointGeneration::getMoppingCoveragePoint(
    algo::CLocalSection& local_section, std::deque<algo::CChainCell>& up_deque_indent,
    std::deque<algo::CChainCell>& down_deque_indent, std::deque<std::deque<algo::CChainCell>>& coverage_deque_up_split,
    std::deque<std::deque<algo::CChainCell>>& coverage_deque_down_split) const 
{
    reverseCoverageDirection(local_section, up_deque_indent, down_deque_indent, coverage_deque_up_split,
                             coverage_deque_down_split);

    //如果不想函数修改成员也可以 auto const &cover_data = local_section.getCoverageData(); 
    //atuo 自动推断. 简洁 等同于 CCoverageData &cover_data = local_section.getCoverageData()
    auto &cover_data = local_section.getCoverageData(); //没有复制任何数据. 调用 getCoverageData() 非const 方法
        

    sparseMoppingCoveragePoint(cover_data, cover_data.getMap(), coverage_deque_up_split, coverage_deque_down_split);
    //直接修改(效率大幅度提高) 
}

 std::deque< CLineInfor > CMeasurePolygon::getPolygonLine(const std::deque< CLineInfor >& LineListInfor,
const CLineSegment& currentLine)
{
      std::deque< CLineSegment > otherLineList;

     ...
    return otherLineList; //非常高效,放心使用  
}

class CChainExtraction
{
     ...
     CChain getLiveChain() //低效(外部可能只是读取)
    {
        return m_current_chain;
    }

    void clearLiveChain() //功能太单一,如果还有其它功能还得继续写函数
    {
        m_current_chain.clearList();
    }

   void setLiveChain(const CChain &val)  //不高效的做法
    {
        m_current_chain = val;  //一定调用复制构造函数
    }

   CChain  m_current_chain;
};

class CChainExtraction
{
    const CChain &getLiveChain() const
    {
        return m_current_chain;
    }

    CChain &getLiveChain()
    {
        return m_current_chain;
    }

/*
    clearLiveChain()
    可以用 getLiveChain().clear(); //替换
*/

/*
    void setLiveChain(const CChain &val)
    可以 getLiveChain() = val; //替换 某些清空下还可以不调用复制函数
    //如果取消get开始更完美

*/

};

//修改前
class TA
{
    void setEn(const enum Ten &a)
    { 
        m_en = a;
    }
     
    const Ten &getEn()
    {
        return m_en;
    }
     
    Ten m_en; 
};

//修改后
class TA
{ //注意:其它基本类型也相似
    void setEn(Ten a) //enum 可以省略.同样如果struct修饰也可以省略
    { 
        m_en = a;
    }
     
    Ten getEn() const //const限定方法, 本身字长不需要用都返回限定
    {
        return m_en;
    }
     
    Ten m_en; 
};