GNU Octave  3.8.0
A high-level interpreted language, primarily intended for numerical computations, mostly compatible with Matlab
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action-container.h
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1 /*
2 
3 Copyright (C) 1993-2013 John W. Eaton
4 Copyright (C) 2009-2010 VZLU Prague
5 
6 This file is part of Octave.
7 
8 Octave is free software; you can redistribute it and/or modify it
9 under the terms of the GNU General Public License as published by the
10 Free Software Foundation; either version 3 of the License, or (at your
11 option) any later version.
12 
13 Octave is distributed in the hope that it will be useful, but WITHOUT
14 ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
15 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
16 for more details.
17 
18 You should have received a copy of the GNU General Public License
19 along with Octave; see the file COPYING. If not, see
20 <http://www.gnu.org/licenses/>.
21 
22 */
23 
24 #if !defined (octave_action_container_h)
25 #define octave_action_container_h 1
26 
27 // This class allows registering actions in a list for later
28 // execution, either explicitly or when the container goes out of
29 // scope.
30 
31 // FIXME: is there a better name for this class?
32 
33 class
35 {
36 public:
37 
38  // A generic unwind_protect element. Knows how to run itself and
39  // discard itself. Also, contains a pointer to the next element.
40  class elem
41  {
42  public:
43  elem (void) { }
44 
45  virtual void run (void) { }
46 
47  virtual ~elem (void) { }
48 
49  friend class action_container;
50 
51  private:
52 
53  // No copying!
54 
55  elem (const elem&);
56 
57  elem& operator = (const elem&);
58  };
59 
60  // An element that merely runs a void (*)(void) function.
61 
62  class fcn_elem : public elem
63  {
64  public:
65  fcn_elem (void (*fptr) (void))
66  : e_fptr (fptr) { }
67 
68  void run (void) { e_fptr (); }
69 
70  private:
71  void (*e_fptr) (void);
72  };
73 
74  // An element that stores a variable of type T along with a void (*) (T)
75  // function pointer, and calls the function with the parameter.
76 
77  template <class T>
78  class fcn_arg_elem : public elem
79  {
80  public:
81  fcn_arg_elem (void (*fcn) (T), T arg)
82  : e_fcn (fcn), e_arg (arg) { }
83 
84  void run (void) { e_fcn (e_arg); }
85 
86  private:
87 
88  // No copying!
89 
90  fcn_arg_elem (const fcn_arg_elem&);
91 
92  fcn_arg_elem& operator = (const fcn_arg_elem&);
93 
94  void (*e_fcn) (T);
95  T e_arg;
96  };
97 
98  // An element that stores a variable of type T along with a
99  // void (*) (const T&) function pointer, and calls the function with
100  // the parameter.
101 
102  template <class T>
103  class fcn_crefarg_elem : public elem
104  {
105  public:
106  fcn_crefarg_elem (void (*fcn) (const T&), const T& arg)
107  : e_fcn (fcn), e_arg (arg) { }
108 
109  void run (void) { e_fcn (e_arg); }
110 
111  private:
112  void (*e_fcn) (const T&);
113  T e_arg;
114  };
115 
116  // An element for calling a member function.
117 
118  template <class T>
119  class method_elem : public elem
120  {
121  public:
122  method_elem (T *obj, void (T::*method) (void))
123  : e_obj (obj), e_method (method) { }
124 
125  void run (void) { (e_obj->*e_method) (); }
126 
127  private:
128 
129  T *e_obj;
130  void (T::*e_method) (void);
131 
132  // No copying!
133 
134  method_elem (const method_elem&);
135 
136  method_elem operator = (const method_elem&);
137  };
138 
139  // An element for calling a member function with a single argument
140 
141  template <class T, class A>
142  class method_arg_elem : public elem
143  {
144  public:
145  method_arg_elem (T *obj, void (T::*method) (A), A arg)
146  : e_obj (obj), e_method (method), e_arg (arg) { }
147 
148  void run (void) { (e_obj->*e_method) (e_arg); }
149 
150  private:
151 
152  T *e_obj;
153  void (T::*e_method) (A);
155 
156  // No copying!
157 
159 
160  method_arg_elem operator = (const method_arg_elem&);
161  };
162 
163  // An element for calling a member function with a single argument
164 
165  template <class T, class A>
166  class method_crefarg_elem : public elem
167  {
168  public:
169  method_crefarg_elem (T *obj, void (T::*method) (const A&), const A& arg)
170  : e_obj (obj), e_method (method), e_arg (arg) { }
171 
172  void run (void) { (e_obj->*e_method) (e_arg); }
173 
174  private:
175 
176  T *e_obj;
177  void (T::*e_method) (const A&);
179 
180  // No copying!
181 
183 
184  method_crefarg_elem operator = (const method_crefarg_elem&);
185  };
186 
187  // An element that stores arbitrary variable, and restores it.
188 
189  template <class T>
190  class restore_var_elem : public elem
191  {
192  public:
193  restore_var_elem (T& ref, const T& val)
194  : e_ptr (&ref), e_val (val) { }
195 
196  void run (void) { *e_ptr = e_val; }
197 
198  private:
199 
200  // No copying!
201 
203 
204  restore_var_elem& operator = (const restore_var_elem&);
205 
206  T *e_ptr, e_val;
207  };
208 
209  // Deletes a class allocated using new.
210 
211  template <class T>
212  class delete_ptr_elem : public elem
213  {
214  public:
216  : e_ptr (ptr) { }
217 
218  void run (void) { delete e_ptr; }
219 
220  private:
221 
222  T *e_ptr;
223 
224  // No copying!
225 
227 
228  delete_ptr_elem operator = (const delete_ptr_elem&);
229  };
230 
231  action_container (void) { }
232 
233  virtual ~action_container (void) { }
234 
235  virtual void add (elem *new_elem) = 0;
236 
237  // Call to void func (void).
238  void add_fcn (void (*fcn) (void))
239  {
240  add (new fcn_elem (fcn));
241  }
242 
243  // Call to void func (T).
244  template <class T>
245  void add_fcn (void (*action) (T), T val)
246  {
247  add (new fcn_arg_elem<T> (action, val));
248  }
249 
250  // Call to void func (const T&).
251  template <class T>
252  void add_fcn (void (*action) (const T&), const T& val)
253  {
254  add (new fcn_crefarg_elem<T> (action, val));
255  }
256 
257  // Call to T::method (void).
258  template <class T>
259  void add_method (T *obj, void (T::*method) (void))
260  {
261  add (new method_elem<T> (obj, method));
262  }
263 
264  // Call to T::method (A).
265  template <class T, class A>
266  void add_method (T *obj, void (T::*method) (A), A arg)
267  {
268  add (new method_arg_elem<T, A> (obj, method, arg));
269  }
270 
271  // Call to T::method (const A&).
272  template <class T, class A>
273  void add_method (T *obj, void (T::*method) (const A&), const A& arg)
274  {
275  add (new method_crefarg_elem<T, A> (obj, method, arg));
276  }
277 
278  // Call to delete (T*).
279 
280  template <class T>
281  void add_delete (T *obj)
282  {
283  add (new delete_ptr_elem<T> (obj));
284  }
285 
286  // Protect any variable.
287  template <class T>
288  void protect_var (T& var)
289  {
290  add (new restore_var_elem<T> (var, var));
291  }
292 
293  // Protect any variable, value given.
294  template <class T>
295  void protect_var (T& var, const T& val)
296  {
297  add (new restore_var_elem<T> (var, val));
298  }
299 
300  operator bool (void) const { return ! empty (); }
301 
302  virtual void run_first (void) = 0;
303 
304  void run (size_t num)
305  {
306  if (num > size ())
307  num = size ();
308 
309  for (size_t i = 0; i < num; i++)
310  run_first ();
311  }
312 
313  void run (void) { run (size ()); }
314 
315  virtual void discard_first (void) = 0;
316 
317  void discard (size_t num)
318  {
319  if (num > size ())
320  num = size ();
321 
322  for (size_t i = 0; i < num; i++)
323  discard_first ();
324  }
325 
326  void discard (void) { discard (size ()); }
327 
328  virtual size_t size (void) const = 0;
329 
330  bool empty (void) const { return size () == 0; }
331 
332 private:
333 
334  // No copying!
335 
337 
338  action_container& operator = (const action_container&);
339 };
340 
341 #endif