[libsigc++2] Add a test case for the previous commit.

[Murray Cumming <murrayc src gnome org>]

commit 2f6fdd52f88ad97e7a260fca08d31c815e426dad
Author: Kjell Ahlstedt <kjell ahlstedt bredband net>
Date:   Tue Jul 19 11:34:05 2011 +0200

    Add a test case for the previous commit.
    
      * tests/Makefile.am:
    	* tests/test_bind_refptr.cc: A version of this test is also in glibmm.
    	Note that this includes a copy/paste of RefPtr.
    	See Bug #564005#14

 tests/test_bind_refptr.cc |  470 +++++++++++++++++++++++++++++++++++++++++++++
 1 files changed, 470 insertions(+), 0 deletions(-)
---
diff --git a/tests/test_bind_refptr.cc b/tests/test_bind_refptr.cc
new file mode 100644
index 0000000..577b285
--- /dev/null
+++ b/tests/test_bind_refptr.cc
@@ -0,0 +1,470 @@
+// Bug 564005 - Valgrind errors and crash on exit with Gtk::UIManager
+// Bug 154498 - Unnecessary warning on console: signalproxy_connectionnode.cc
+
+// libsigc++-only test case. (Or almost so. RefPtr is stolen from glibmm.)
+
+// -*- c++ -*-
+#ifndef _GLIBMM_REFPTR_H
+#define _GLIBMM_REFPTR_H
+
+/* Copyright 2002 The gtkmm Development Team
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library 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
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free
+ * Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+//#include <glibmmconfig.h>
+
+namespace Glib
+{
+
+/** RefPtr<> is a reference-counting shared smartpointer.
+ *
+ * Some objects in gtkmm are obtained from a shared
+ * store. Consequently you cannot instantiate them yourself. Instead they
+ * return a RefPtr which behaves much like an ordinary pointer in that members
+ * can be reached with the usual <code>object_ptr->member</code> notation.
+ * Unlike most other smart pointers, RefPtr doesn't support dereferencing
+ * through <code>*object_ptr</code>.
+ *
+ * Reference counting means that a shared reference count is incremented each
+ * time a RefPtr is copied, and decremented each time a RefPtr is destroyed,
+ * for instance when it leaves its scope. When the reference count reaches
+ * zero, the contained object is deleted, meaning  you don't need to remember
+ * to delete the object.
+ *
+ * RefPtr<> can store any class that has reference() and unreference() methods.
+ * In gtkmm, that is anything derived from Glib::ObjectBase, such as
+ * Gdk::Pixmap.
+ *
+ * See the "Memory Management" section in the "Programming with gtkmm"
+ * book for further information.
+ */
+template <class T_CppObject>
+class RefPtr
+{
+public:
+  /** Default constructor
+   *
+   * Afterwards it will be null and use of -> will cause a segmentation fault.
+   */
+  inline RefPtr();
+  
+  /// Destructor - decrements reference count.
+  inline ~RefPtr();
+
+  /// For use only by the ::create() methods.
+  explicit inline RefPtr(T_CppObject* pCppObject);
+
+  /** Copy constructor
+   *
+   * This increments the shared reference count.
+   */
+  inline RefPtr(const RefPtr<T_CppObject>& src);
+
+  /** Copy constructor (from different, but castable type).
+   *
+   * Increments the reference count.
+   */
+  template <class T_CastFrom>
+  inline RefPtr(const RefPtr<T_CastFrom>& src);
+
+  /** Swap the contents of two RefPtr<>.
+   * This method swaps the internal pointers to T_CppObject.  This can be
+   * done safely without involving a reference/unreference cycle and is
+   * therefore highly efficient.
+   */
+  inline void swap(RefPtr<T_CppObject>& other);
+
+  /// Copy from another RefPtr:
+  inline RefPtr<T_CppObject>& operator=(const RefPtr<T_CppObject>& src);
+
+  /** Copy from different, but castable type).
+   *
+   * Increments the reference count.
+   */
+  template <class T_CastFrom>
+  inline RefPtr<T_CppObject>& operator=(const RefPtr<T_CastFrom>& src);
+
+  /// Tests whether the RefPtr<> point to the same underlying instance.
+  inline bool operator==(const RefPtr<T_CppObject>& src) const;
+  
+  /// See operator==().
+  inline bool operator!=(const RefPtr<T_CppObject>& src) const;
+
+  /** Dereferencing.
+   *
+   * Use the methods of the underlying instance like so:
+   * <code>refptr->memberfun()</code>.
+   */
+  inline T_CppObject* operator->() const;
+
+  /** Test whether the RefPtr<> points to any underlying instance.
+   *
+   * Mimics usage of ordinary pointers:
+   * @code
+   *   if (ptr)
+   *     do_something();
+   * @endcode
+   */
+  inline operator bool() const;
+
+#ifndef GLIBMM_DISABLE_DEPRECATED
+  /// @deprecated Use reset() instead because this leads to confusion with clear() methods on the underlying class. For instance, people use .clear() when they mean ->clear().
+  inline void clear();
+#endif //GLIBMM_DISABLE_DEPRECATED
+
+  /** Set underlying instance to 0, decrementing reference count of existing instance appropriately.
+   * @newin{2,16}
+   */
+  inline void reset();
+
+  /** Dynamic cast to derived class.
+   *
+   * The RefPtr can't be cast with the usual notation so instead you can use
+   * @code
+   *   ptr_derived = RefPtr<Derived>::cast_dynamic(ptr_base);
+   * @endcode
+   */
+  template <class T_CastFrom>
+  static inline RefPtr<T_CppObject> cast_dynamic(const RefPtr<T_CastFrom>& src);
+
+  /** Static cast to derived class.
+   *
+   * Like the dynamic cast; the notation is 
+   * @code
+   *   ptr_derived = RefPtr<Derived>::cast_static(ptr_base);
+   * @endcode
+   */
+  template <class T_CastFrom>
+  static inline RefPtr<T_CppObject> cast_static(const RefPtr<T_CastFrom>& src);
+
+  /** Cast to non-const.
+   *
+   * The RefPtr can't be cast with the usual notation so instead you can use
+   * @code
+   *   ptr_unconst = RefPtr<UnConstType>::cast_const(ptr_const);
+   * @endcode
+   */
+  template <class T_CastFrom>
+  static inline RefPtr<T_CppObject> cast_const(const RefPtr<T_CastFrom>& src);
+
+  //TODO: Maybe remove these if we replace operator bool() with operator const void* after 
+  //an API/ABI break, as suggested by Daniel Elstner? murrayc.
+  //See bug https://bugzilla.gnome.org/show_bug.cgi?id=626858
+
+  /** Compare based on the underlying instance address.
+   *
+   * This is needed in code that requires an ordering on
+   * RefPtr<T_CppObject> instances, e.g. std::set<RefPtr<T_CppObject> >.
+   *
+   * Without these, comparing two RefPtr<T_CppObject> instances
+   * is still syntactically possible, but the result is semantically
+   * wrong, as p1 REL_OP p2 is interpreted as (bool)p1 REL_OP (bool)p2.
+   */
+  inline bool operator<(const RefPtr<T_CppObject>& src) const;
+
+  /// See operator<().
+  inline bool operator<=(const RefPtr<T_CppObject>& src) const;
+
+  /// See operator<().
+  inline bool operator>(const RefPtr<T_CppObject>& src) const;
+
+  /// See operator<().
+  inline bool operator>=(const RefPtr<T_CppObject>& src) const;
+
+private:
+  T_CppObject* pCppObject_;
+};
+
+
+#ifndef DOXYGEN_SHOULD_SKIP_THIS
+
+// RefPtr<>::operator->() comes first here since it's used by other methods.
+// If it would come after them it wouldn't be inlined.
+
+template <class T_CppObject> inline
+T_CppObject* RefPtr<T_CppObject>::operator->() const
+{
+  return pCppObject_;
+}
+
+template <class T_CppObject> inline
+RefPtr<T_CppObject>::RefPtr()
+:
+  pCppObject_ (0)
+{}
+
+template <class T_CppObject> inline
+RefPtr<T_CppObject>::~RefPtr()
+{
+  if(pCppObject_)
+    pCppObject_->unreference(); // This could cause pCppObject to be deleted.
+}
+
+template <class T_CppObject> inline
+RefPtr<T_CppObject>::RefPtr(T_CppObject* pCppObject)
+:
+  pCppObject_ (pCppObject)
+{}
+
+template <class T_CppObject> inline
+RefPtr<T_CppObject>::RefPtr(const RefPtr<T_CppObject>& src)
+:
+  pCppObject_ (src.pCppObject_)
+{
+  if(pCppObject_)
+    pCppObject_->reference();
+}
+
+// The templated ctor allows copy construction from any object that's
+// castable.  Thus, it does downcasts:
+//   base_ref = derived_ref
+template <class T_CppObject>
+  template <class T_CastFrom>
+inline
+RefPtr<T_CppObject>::RefPtr(const RefPtr<T_CastFrom>& src)
+:
+  // A different RefPtr<> will not allow us access to pCppObject_.  We need
+  // to add a get_underlying() for this, but that would encourage incorrect
+  // use, so we use the less well-known operator->() accessor:
+  pCppObject_ (src.operator->())
+{
+  if(pCppObject_)
+    pCppObject_->reference();
+}
+
+template <class T_CppObject> inline
+void RefPtr<T_CppObject>::swap(RefPtr<T_CppObject>& other)
+{
+  T_CppObject *const temp = pCppObject_;
+  pCppObject_ = other.pCppObject_;
+  other.pCppObject_ = temp;
+}
+
+template <class T_CppObject> inline
+RefPtr<T_CppObject>& RefPtr<T_CppObject>::operator=(const RefPtr<T_CppObject>& src)
+{
+  // In case you haven't seen the swap() technique to implement copy
+  // assignment before, here's what it does:
+  //
+  // 1) Create a temporary RefPtr<> instance via the copy ctor, thereby
+  //    increasing the reference count of the source object.
+  //
+  // 2) Swap the internal object pointers of *this and the temporary
+  //    RefPtr<>.  After this step, *this already contains the new pointer,
+  //    and the old pointer is now managed by temp.
+  //
+  // 3) The destructor of temp is executed, thereby unreferencing the
+  //    old object pointer.
+  //
+  // This technique is described in Herb Sutter's "Exceptional C++", and
+  // has a number of advantages over conventional approaches:
+  //
+  // - Code reuse by calling the copy ctor.
+  // - Strong exception safety for free.
+  // - Self assignment is handled implicitely.
+  // - Simplicity.
+  // - It just works and is hard to get wrong; i.e. you can use it without
+  //   even thinking about it to implement copy assignment whereever the
+  //   object data is managed indirectly via a pointer, which is very common.
+
+  RefPtr<T_CppObject> temp (src);
+  this->swap(temp);
+  return *this;
+}
+
+template <class T_CppObject>
+  template <class T_CastFrom>
+inline
+RefPtr<T_CppObject>& RefPtr<T_CppObject>::operator=(const RefPtr<T_CastFrom>& src)
+{
+  RefPtr<T_CppObject> temp (src);
+  this->swap(temp);
+  return *this;
+}
+
+template <class T_CppObject> inline
+bool RefPtr<T_CppObject>::operator==(const RefPtr<T_CppObject>& src) const
+{
+  return (pCppObject_ == src.pCppObject_);
+}
+
+template <class T_CppObject> inline
+bool RefPtr<T_CppObject>::operator!=(const RefPtr<T_CppObject>& src) const
+{
+  return (pCppObject_ != src.pCppObject_);
+}
+
+template <class T_CppObject> inline
+RefPtr<T_CppObject>::operator bool() const
+{
+  return (pCppObject_ != 0);
+}
+
+#ifndef GLIBMM_DISABLE_DEPRECATED
+template <class T_CppObject> inline
+void RefPtr<T_CppObject>::clear()
+{
+  reset();
+}
+#endif //GLIBMM_DISABLE_DEPRECATED
+
+template <class T_CppObject> inline
+void RefPtr<T_CppObject>::reset()
+{
+  RefPtr<T_CppObject> temp; // swap with an empty RefPtr<> to clear *this
+  this->swap(temp);
+}
+
+template <class T_CppObject>
+  template <class T_CastFrom>
+inline
+RefPtr<T_CppObject> RefPtr<T_CppObject>::cast_dynamic(const RefPtr<T_CastFrom>& src)
+{
+  T_CppObject *const pCppObject = dynamic_cast<T_CppObject*>(src.operator->());
+
+  if(pCppObject)
+    pCppObject->reference();
+
+  return RefPtr<T_CppObject>(pCppObject);
+}
+
+template <class T_CppObject>
+  template <class T_CastFrom>
+inline
+RefPtr<T_CppObject> RefPtr<T_CppObject>::cast_static(const RefPtr<T_CastFrom>& src)
+{
+  T_CppObject *const pCppObject = static_cast<T_CppObject*>(src.operator->());
+
+  if(pCppObject)
+    pCppObject->reference();
+
+  return RefPtr<T_CppObject>(pCppObject);
+}
+
+template <class T_CppObject>
+  template <class T_CastFrom>
+inline
+RefPtr<T_CppObject> RefPtr<T_CppObject>::cast_const(const RefPtr<T_CastFrom>& src)
+{
+  T_CppObject *const pCppObject = const_cast<T_CppObject*>(src.operator->());
+
+  if(pCppObject)
+    pCppObject->reference();
+
+  return RefPtr<T_CppObject>(pCppObject);
+}
+
+template <class T_CppObject> inline
+bool RefPtr<T_CppObject>::operator<(const RefPtr<T_CppObject>& src) const
+{
+  return (pCppObject_ < src.pCppObject_);
+}
+
+template <class T_CppObject> inline
+bool RefPtr<T_CppObject>::operator<=(const RefPtr<T_CppObject>& src) const
+{
+  return (pCppObject_ <= src.pCppObject_);
+}
+
+template <class T_CppObject> inline
+bool RefPtr<T_CppObject>::operator>(const RefPtr<T_CppObject>& src) const
+{
+  return (pCppObject_ > src.pCppObject_);
+}
+
+template <class T_CppObject> inline
+bool RefPtr<T_CppObject>::operator>=(const RefPtr<T_CppObject>& src) const
+{
+  return (pCppObject_ >= src.pCppObject_);
+}
+
+#endif /* DOXYGEN_SHOULD_SKIP_THIS */
+
+/** @relates Glib::RefPtr */
+template <class T_CppObject> inline
+void swap(RefPtr<T_CppObject>& lhs, RefPtr<T_CppObject>& rhs)
+{
+  lhs.swap(rhs);
+}
+
+} // namespace Glib
+
+
+#endif /* _GLIBMM_REFPTR_H */
+
+
+#include <sigc++/sigc++.h>
+#include <iostream>
+#include <stdlib.h>
+
+#define ACTIVATE_BUG 1
+
+class Action : public sigc::trackable
+{
+public:
+  Action() : ref_count(1) { }
+
+  void reference() { ++ref_count; }
+  void unreference() { if (--ref_count <= 0) delete this; }
+
+  void emit_sig1(int n) { sig1.emit(n); }
+
+  sigc::signal<void, int>& signal_sig1() { return sig1; }
+
+private:
+  sigc::signal<void, int> sig1;
+  int ref_count;
+
+};
+
+class Test : public sigc::trackable
+{
+public:
+  Test()
+  : action(new Action)
+  {
+    //std::cout << "new Test" << std::endl;
+#ifdef ACTIVATE_BUG //See https://bugzilla.gnome.org/show_bug.cgi?id=564005#c15s
+    action->signal_sig1().connect(sigc::bind(sigc::mem_fun(this, &Test::on_sig1), action));
+#else
+    Glib::RefPtr<Action> action2(new Action);
+    action->signal_sig1().connect(sigc::bind(sigc::mem_fun(this, &Test::on_sig1), action2));
+#endif
+  }
+
+  ~Test()
+  {
+    //std::cout << "delete Test" << std::endl;
+  }
+
+  void on_sig1(int /* n */, Glib::RefPtr<Action> /* action */)
+  {
+    //std::cout << "Test::on_sig1, n=" << n << std::endl;
+  }
+  
+  Glib::RefPtr<Action> action;
+
+}; // end Test
+
+int main(int, char**)
+{
+  Test* test = new Test;
+
+  test->action->emit_sig1(23);
+  delete test;
+
+  return EXIT_SUCCESS;
+}