--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/libinterp/interp-core/action-container.h	Mon Sep 17 19:52:20 2012 -0400
@@ -0,0 +1,342 @@
+/*
+
+Copyright (C) 1993-2012 John W. Eaton
+Copyright (C) 2009-2010 VZLU Prague
+
+This file is part of Octave.
+
+Octave is free software; you can redistribute it and/or modify it
+under the terms of the GNU General Public License as published by the
+Free Software Foundation; either version 3 of the License, or (at your
+option) any later version.
+
+Octave is distributed in the hope that it will be useful, but WITHOUT
+ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+for more details.
+
+You should have received a copy of the GNU General Public License
+along with Octave; see the file COPYING.  If not, see
+<http://www.gnu.org/licenses/>.
+
+*/
+
+#if !defined (octave_action_container_h)
+#define octave_action_container_h 1
+
+// This class allows registering actions in a list for later
+// execution, either explicitly or when the container goes out of
+// scope.
+
+// FIXME -- is there a better name for this class?
+
+class
+OCTINTERP_API
+action_container
+{
+public:
+
+  // A generic unwind_protect element. Knows how to run itself and
+  // discard itself.  Also, contains a pointer to the next element.
+  class elem
+  {
+  public:
+    elem (void) { }
+
+    virtual void run (void) { }
+
+    virtual ~elem (void) { }
+
+    friend class action_container;
+
+  private:
+
+    // No copying!
+
+    elem (const elem&);
+
+    elem& operator = (const elem&);
+  };
+
+  // An element that merely runs a void (*)(void) function.
+
+  class fcn_elem : public elem
+  {
+  public:
+    fcn_elem (void (*fptr) (void))
+      : e_fptr (fptr) { }
+
+    void run (void) { e_fptr (); }
+
+  private:
+    void (*e_fptr) (void);
+  };
+
+  // An element that stores a variable of type T along with a void (*) (T)
+  // function pointer, and calls the function with the parameter.
+
+  template <class T>
+  class fcn_arg_elem : public elem
+  {
+  public:
+    fcn_arg_elem (void (*fcn) (T), T arg)
+      : e_fcn (fcn), e_arg (arg) { }
+
+    void run (void) { e_fcn (e_arg); }
+
+  private:
+
+    // No copying!
+
+    fcn_arg_elem (const fcn_arg_elem&);
+
+    fcn_arg_elem& operator = (const fcn_arg_elem&);
+
+    void (*e_fcn) (T);
+    T e_arg;
+  };
+
+  // An element that stores a variable of type T along with a
+  // void (*) (const T&) function pointer, and calls the function with
+  // the parameter.
+
+  template <class T>
+  class fcn_crefarg_elem : public elem
+  {
+  public:
+    fcn_crefarg_elem (void (*fcn) (const T&), const T& arg)
+      : e_fcn (fcn), e_arg (arg) { }
+
+    void run (void) { e_fcn (e_arg); }
+
+  private:
+    void (*e_fcn) (const T&);
+    T e_arg;
+  };
+
+  // An element for calling a member function.
+
+  template <class T>
+  class method_elem : public elem
+  {
+  public:
+    method_elem (T *obj, void (T::*method) (void))
+      : e_obj (obj), e_method (method) { }
+
+    void run (void) { (e_obj->*e_method) (); }
+
+  private:
+
+    T *e_obj;
+    void (T::*e_method) (void);
+
+    // No copying!
+
+    method_elem (const method_elem&);
+
+    method_elem operator = (const method_elem&);
+  };
+
+  // An element for calling a member function with a single argument
+
+  template <class T, class A>
+  class method_arg_elem : public elem
+  {
+  public:
+    method_arg_elem (T *obj, void (T::*method) (A), A arg)
+      : e_obj (obj), e_method (method), e_arg (arg) { }
+
+    void run (void) { (e_obj->*e_method) (e_arg); }
+
+  private:
+
+    T *e_obj;
+    void (T::*e_method) (A);
+    A e_arg;
+
+    // No copying!
+
+    method_arg_elem (const method_arg_elem&);
+
+    method_arg_elem operator = (const method_arg_elem&);
+  };
+
+  // An element for calling a member function with a single argument
+
+  template <class T, class A>
+  class method_crefarg_elem : public elem
+  {
+  public:
+    method_crefarg_elem (T *obj, void (T::*method) (const A&), const A& arg)
+      : e_obj (obj), e_method (method), e_arg (arg) { }
+
+    void run (void) { (e_obj->*e_method) (e_arg); }
+
+  private:
+
+    T *e_obj;
+    void (T::*e_method) (const A&);
+    A e_arg;
+
+    // No copying!
+
+    method_crefarg_elem (const method_crefarg_elem&);
+
+    method_crefarg_elem operator = (const method_crefarg_elem&);
+  };
+
+  // An element that stores arbitrary variable, and restores it.
+
+  template <class T>
+  class restore_var_elem : public elem
+  {
+  public:
+    restore_var_elem (T& ref, const T& val)
+      : e_ptr (&ref), e_val (val) { }
+
+    void run (void) { *e_ptr = e_val; }
+
+  private:
+
+    // No copying!
+
+    restore_var_elem (const restore_var_elem&);
+
+    restore_var_elem& operator = (const restore_var_elem&);
+
+    T *e_ptr, e_val;
+  };
+
+  // Deletes a class allocated using new.
+
+  template <class T>
+  class delete_ptr_elem : public elem
+  {
+  public:
+    delete_ptr_elem (T *ptr)
+      : e_ptr (ptr) { }
+
+    void run (void) { delete e_ptr; }
+
+  private:
+
+    T *e_ptr;
+
+    // No copying!
+
+    delete_ptr_elem (const delete_ptr_elem&);
+
+    delete_ptr_elem operator = (const delete_ptr_elem&);
+  };
+
+  action_container (void) { }
+
+  virtual ~action_container (void) { }
+
+  virtual void add (elem *new_elem) = 0;
+
+  // Call to void func (void).
+  void add_fcn (void (*fcn) (void))
+  {
+    add (new fcn_elem (fcn));
+  }
+
+  // Call to void func (T).
+  template <class T>
+  void add_fcn (void (*action) (T), T val)
+  {
+    add (new fcn_arg_elem<T> (action, val));
+  }
+
+  // Call to void func (const T&).
+  template <class T>
+  void add_fcn (void (*action) (const T&), const T& val)
+  {
+    add (new fcn_crefarg_elem<T> (action, val));
+  }
+
+  // Call to T::method (void).
+  template <class T>
+  void add_method (T *obj, void (T::*method) (void))
+  {
+    add (new method_elem<T> (obj, method));
+  }
+
+  // Call to T::method (A).
+  template <class T, class A>
+  void add_method (T *obj, void (T::*method) (A), A arg)
+  {
+    add (new method_arg_elem<T, A> (obj, method, arg));
+  }
+
+  // Call to T::method (const A&).
+  template <class T, class A>
+  void add_method (T *obj, void (T::*method) (const A&), const A& arg)
+  {
+    add (new method_crefarg_elem<T, A> (obj, method, arg));
+  }
+
+  // Call to delete (T*).
+
+  template <class T>
+  void add_delete (T *obj)
+  {
+    add (new delete_ptr_elem<T> (obj));
+  }
+
+  // Protect any variable.
+  template <class T>
+  void protect_var (T& var)
+  {
+    add (new restore_var_elem<T> (var, var));
+  }
+
+  // Protect any variable, value given.
+  template <class T>
+  void protect_var (T& var, const T& val)
+  {
+    add (new restore_var_elem<T> (var, val));
+  }
+
+  operator bool (void) const { return ! empty (); }
+
+  virtual void run_first (void) = 0;
+
+  void run (size_t num)
+  {
+    if (num > size ())
+      num = size ();
+
+    for (size_t i = 0; i < num; i++)
+      run_first ();
+  }
+
+  void run (void) { run (size ()); }
+
+  virtual void discard_first (void) = 0;
+
+  void discard (size_t num)
+  {
+    if (num > size ())
+      num = size ();
+
+    for (size_t i = 0; i < num; i++)
+      discard_first ();
+  }
+
+  void discard (void) { discard (size ()); }
+
+  virtual size_t size (void) const = 0;
+
+  bool empty (void) const { return size () == 0; }
+
+private:
+
+  // No copying!
+
+  action_container (const action_container&);
+
+  action_container& operator = (const action_container&);
+};
+
+#endif