变量名后面加下划线是什么命名规则？

class ScopeGuard

{

public:

    explicit ScopeGuard(std::function<void()> onExitScope)

        : onExitScope_(onExitScope), dismissed_(false)

    { }



    ~ScopeGuard()

    {

        if(!dismissed_)

        {

            onExitScope_();

        }

    }



    void Dismiss()

    {

        dismissed_ = true;

    }



private:

    std::function<void()> onExitScope_;

    bool dismissed_;



private: // noncopyable

    ScopeGuard(ScopeGuard const&);

    ScopeGuard& operator=(ScopeGuard const&);

};