class utils::OnEnd — HIRO 0.7.0 documentation

# class utils::OnEnd

## Overview

Helper class that performs an action when it is destroyed. More…

    #include <OnEnd.h>

    class OnEnd {
    public:
        // typedefs

        typedef std::function<void()> Callback;

        // construction

        OnEnd(Callback F);
        OnEnd(const OnEnd&);
        OnEnd(OnEnd&&);
        ~OnEnd();

        // methods

        OnEnd& operator=(const OnEnd&);
        OnEnd& operator=(OnEnd&&);
    };

## Detailed Documentation

Helper class that performs an action when it is destroyed.

Motivation:

- When a function has many boundary conditions and returns in multiple places.

Example usage:

    bool Init()
    {
      m->device->LockGUI();                         // Locks GUI
      OnEnd _([&]() { m->device->UnlockGUI(); });

      if (condition_1)
        return false;                               // GUI is unlocked

      if (condition_2)
        return false;                               // GUI is unlocked

      return true;                                  // GUI is unlocked
    }

### Typedefs

    typedef std::function<void()> Callback

Callback is a void function taking 0 arguments.

### Construction

    OnEnd(Callback F)

Constructor sets Callback.

    ~OnEnd()

Destructor calls Callback.