[glom/C++14: 4/4] C++14: Use decltype(auto) for return types of some templated methods.

[Murray Cumming <murrayc src gnome org>]

commit f5c09d37a114be2ca7bb725f55d9507fa6584c41
Author: Murray Cumming <murrayc murrayc com>
Date:   Mon Jan 4 12:07:12 2016 +0100

    C++14: Use decltype(auto) for return types of some templated methods.

 glom/glade_utils.h                       |    6 ++++--
 glom/libglom/utils.h                     |    2 +-
 tests/test_document_load_translations.cc |    3 ++-
 3 files changed, 7 insertions(+), 4 deletions(-)
---
diff --git a/glom/glade_utils.h b/glom/glade_utils.h
index 77e2daa..e438bdb 100644
--- a/glom/glade_utils.h
+++ b/glom/glade_utils.h
@@ -47,7 +47,8 @@ inline std::string get_glade_resource_path(const std::string& filename)
  * such as a GtkSpinButton's GtkAdjustment.
  */
 template<class T_Widget>
-Glib::RefPtr<Gtk::Builder> helper_get_glade_widget_derived_with_warning(const std::string& filename, const 
Glib::ustring& id, T_Widget*& widget, bool load_all)
+decltype(auto)
+helper_get_glade_widget_derived_with_warning(const std::string& filename, const Glib::ustring& id, 
T_Widget*& widget, bool load_all)
 {
   Glib::RefPtr<Gtk::Builder> refXml;
 
@@ -92,7 +93,8 @@ Glib::RefPtr<Gtk::Builder> helper_get_glade_widget_derived_with_warning(const st
  * will be deleted immediately.
  */
 template<class T_Widget>
-Glib::RefPtr<Gtk::Builder> get_glade_child_widget_derived_with_warning(T_Widget*& widget)
+decltype(auto)
+get_glade_child_widget_derived_with_warning(T_Widget*& widget)
 {
   // Check the path to the installed .glade file:
   // The id is the same as the filename, in a developer/operator sub-directory:
diff --git a/glom/libglom/utils.h b/glom/libglom/utils.h
index d12dcf7..63e916d 100644
--- a/glom/libglom/utils.h
+++ b/glom/libglom/utils.h
@@ -256,7 +256,7 @@ bool script_check_for_pygtk2(const Glib::ustring& script);
 bool get_resource_exists(const std::string& resource_path);
 
 template<typename E>
-constexpr typename std::underlying_type<E>::type
+decltype(auto)
 to_utype(E enumerator) noexcept
 {
   return static_cast<typename std::underlying_type<E>::type>(enumerator);
diff --git a/tests/test_document_load_translations.cc b/tests/test_document_load_translations.cc
index 11fa026..3305151 100644
--- a/tests/test_document_load_translations.cc
+++ b/tests/test_document_load_translations.cc
@@ -39,7 +39,8 @@ bool contains(const T_Container& container, const T_Value& name)
 }
 
 template<typename T_Container>
-typename T_Container::value_type get_titled(const T_Container& container, const Glib::ustring& title)
+decltype(auto)
+get_titled(const T_Container& container, const Glib::ustring& title)
 {
   typedef typename T_Container::value_type type_sharedptr;
   type_sharedptr result;