Supporting Ubuntu 14.

src/directories.cc

@@ -9,7 +9,13 @@
 using namespace std; //TODO: remove
 
 namespace sigc {
-  SIGC_FUNCTORS_DEDUCE_RESULT_TYPE_WITH_DECLTYPE
+  template <typename Functor>
+  struct functor_trait<Functor, false> {
+    typedef decltype (::sigc::mem_fun(std::declval<Functor&>(),
+                                      &Functor::operator())) _intermediate;
+    typedef typename _intermediate::result_type result_type;
+    typedef Functor functor_type;
+  };
 }
 
 Directories::Directories() : stop_update_thread(false) {

src/entrybox.cc

@@ -1,7 +1,13 @@
 #include "entrybox.h"
 
 namespace sigc {
-  SIGC_FUNCTORS_DEDUCE_RESULT_TYPE_WITH_DECLTYPE
+  template <typename Functor>
+  struct functor_trait<Functor, false> {
+    typedef decltype (::sigc::mem_fun(std::declval<Functor&>(),
+                                      &Functor::operator())) _intermediate;
+    typedef typename _intermediate::result_type result_type;
+    typedef Functor functor_type;
+  };
 }
 
 std::unordered_map<std::string, std::vector<std::string> > EntryBox::entry_histories;

src/notebook.cc

@@ -10,7 +10,13 @@
 using namespace std; //TODO: remove
 
 namespace sigc {
-  SIGC_FUNCTORS_DEDUCE_RESULT_TYPE_WITH_DECLTYPE
+  template <typename Functor>
+  struct functor_trait<Functor, false> {
+    typedef decltype (::sigc::mem_fun(std::declval<Functor&>(),
+                                      &Functor::operator())) _intermediate;
+    typedef typename _intermediate::result_type result_type;
+    typedef Functor functor_type;
+  };
 }
 
 Notebook::Notebook(Directories &directories) : Gtk::Notebook(), directories(directories) {

src/selectiondialog.cc

@@ -2,7 +2,13 @@
 #include <algorithm>
 
 namespace sigc {
-  SIGC_FUNCTORS_DEDUCE_RESULT_TYPE_WITH_DECLTYPE
+  template <typename Functor>
+  struct functor_trait<Functor, false> {
+    typedef decltype (::sigc::mem_fun(std::declval<Functor&>(),
+                                      &Functor::operator())) _intermediate;
+    typedef typename _intermediate::result_type result_type;
+    typedef Functor functor_type;
+  };
 }
 
 SelectionDialogBase::SelectionDialogBase(Gtk::TextView& text_view, Glib::RefPtr<Gtk::TextBuffer::Mark> start_mark, bool show_search_entry): text_view(text_view), 

src/source.cc

@@ -12,7 +12,13 @@
 using namespace std; //TODO: remove
 
 namespace sigc {
-  SIGC_FUNCTORS_DEDUCE_RESULT_TYPE_WITH_DECLTYPE
+  template <typename Functor>
+  struct functor_trait<Functor, false> {
+    typedef decltype (::sigc::mem_fun(std::declval<Functor&>(),
+                                      &Functor::operator())) _intermediate;
+    typedef typename _intermediate::result_type result_type;
+    typedef Functor functor_type;
+  };
 }
 
 Glib::RefPtr<Gsv::Language> Source::guess_language(const boost::filesystem::path &file_path) {

src/tooltips.cc

@@ -2,7 +2,13 @@
 #include "singletons.h"
 
 namespace sigc {
-  SIGC_FUNCTORS_DEDUCE_RESULT_TYPE_WITH_DECLTYPE
+  template <typename Functor>
+  struct functor_trait<Functor, false> {
+    typedef decltype (::sigc::mem_fun(std::declval<Functor&>(),
+                                      &Functor::operator())) _intermediate;
+    typedef typename _intermediate::result_type result_type;
+    typedef Functor functor_type;
+  };
 }
 
 Gdk::Rectangle Tooltips::drawn_tooltips_rectangle=Gdk::Rectangle();

src/window.cc

@@ -10,7 +10,13 @@
 using namespace std; //TODO: remove
 
 namespace sigc {
-  SIGC_FUNCTORS_DEDUCE_RESULT_TYPE_WITH_DECLTYPE
+  template <typename Functor>
+  struct functor_trait<Functor, false> {
+    typedef decltype (::sigc::mem_fun(std::declval<Functor&>(),
+                                      &Functor::operator())) _intermediate;
+    typedef typename _intermediate::result_type result_type;
+    typedef Functor functor_type;
+  };
 }
 
 void Window::generate_keybindings() {