Current plugin scoping

class PluginScoper
{
public:
  PluginScoper (CMUSHclientDoc* doc, CPlugin* plugin)
    : _doc(doc)
  {
    _saved_plugin = _doc.m_CurrentPlugin;
    _doc.m_CurrentPlugin = plugin;
  }

  ~PluginScoper ()
  {
    _doc.m_CurrentPlugin = _saved_plugin;
  }

private:
  CMUSHclientDoc* _doc;
  CPlugin* _saved_plugin;
};

{
  PluginScoper pscope (doc, plugin);
  // stuff here

  // automatically reset here
}

{
PluginScoper pscope (m_pDoc, NULL);

// a code loop
  {
  m_pDoc->m_CurrentPlugin = foo;
  }

// automatically reset here
}

class CurrentPluginScoper
{
public:
  CurrentPluginScoper (CMUSHclientDoc* doc)
    : _doc(doc), _saved_plugin(doc.m_CurrentPlugin)
  {}

  ~CurrentPluginScoper ()
  {
    _doc.m_CurrentPlugin = _saved_plugin;
  }

private:
  CMUSHclientDoc* _doc;
  CPlugin* _saved_plugin;
};

{
CurrentPluginScoper pscope (m_pDoc);

// a code loop
  {
  m_pDoc->m_CurrentPlugin = foo;
  }

// automatically reset here
}

PluginScoper& operator= (CPlugin* plugin)
{
  _doc->m_CurrentPlugin = plugin;
  return *this;
}

{
  PluginScoper current_plugin(m_pDoc);

  // some dummy loop here
  while (true)
    current_plugin = some_plugin;
}

while (true)
{
  CurrentPluginScope (m_pDoc, some_plugin);
  // stuff
}

CurrentPluginScope pscope (pDoc); // saves current plugin

pDoc->m_CurrentPlugin = stuff; // this is done manually

// reset automatically

CurrentPluginScope pScope (pDoc, plugin); // saves as well as sets

// do stuff

// reset automatically

void do_stuff (CPlugin* plugin)
{
  CPlugin* pSavedPlugin = m_pDoc->m_CurrentPlugin;
  m_pDoc->m_CurrentPlugin = plugin;
  // where does m_pDoc come from? honest question
  // is do_stuff supposed to be a functor which takes
  // m_pDoc as a ctor parameter?

  // Do stuff

  m_pDoc->m_CurrentPlugin = pSavedPlugin;
}

{
CurrentPluginScope pscope (pDoc); // saves current plugin

// lengthy loops and processing here (eg. 60 lines)

...

// at end of scope of { ... } block then:

// destructor of pscope does an un-obvious assignment:  
// pDoc->m_CurrentPlugin = pSavedPlugin; 

}  

{
CPlugin* pSavedPlugin = m_CurrentPlugin; // saves current plugin

// lengthy loops and processing here (eg. 60 lines)

...

// at end of scope of { ... } block then:

m_CurrentPlugin = pSavedPlugin; // restore current plugin
}  

template <class ITER, class F> inline
F for_each (ITER first, ITER last, F func)
  {
  for ( ; first != last; ++first)
    func (*first);
  return func;
  }

template <class ITER, class F> inline
F safe_for_each (ITER first, ITER last, F func)
  {
  while (first != last)
    func (*first++);
  return func;
  }