ScopeGuard

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&);
};

这个类的使用很简单，你交给它一个std::function，它负责在析构的时候执行，绝大多数时候这个function就是lambda，例如：

HANDLE h = CreateFile(...);
ScopeGuard onExit([&] { CloseHandle(h); });
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&);
};

这个类的使用很简单，你交给它一个std::function，它负责在析构的时候执行，绝大多数时候这个function就是lambda，例如：

HANDLE h = CreateFile(...); ScopeGuard onExit([&] { CloseHandle(h); });