cxx: Fix examples compilation.

Summary:
- Changed beta methods guards from CLASS_NAME_GUARD to
  EFL_BETA_API_SUPPORT to use the same scheme as C.
- Removed some includes to Efl_Ui.h from the examples. These were
  causing C's efl_part_get to not be generated due to EFL_PART_PROTECTED
  not being yet defined (it is defined in Elementary.hh, included
  afterwards). This was leading to Efl.Part.impl.hh trying to use a
  non-existent method.

Fixes T7716 partially (missing stringshare issue)

Test Plan: make examples

Reviewers: stefan_schmidt, felipealmeida, zmike

Reviewed By: zmike

Subscribers: cedric, #reviewers, #committers

Tags: #efl

Maniphest Tasks: T7716

Differential Revision: https://phab.enlightenment.org/D8284

src/examples/elementary/bg_cxx_example_01.cc

@@ -1,4 +1,5 @@
 #define EFL_CXXPERIMENTAL // for background part
+#define EFL_BETA_API_SUPPORT
 #include <Elementary.hh>
 
 using efl::eo::instantiate;

src/examples/elementary/bg_cxx_example_02.cc

@@ -6,6 +6,7 @@
  */
 
 #define EFL_CXXPERIMENTAL
+#define EFL_BETA_API_SUPPORT
 
 #include <Elementary.hh>
 

src/examples/elementary/button_cxx_example_00.cc

@@ -1,6 +1,7 @@
 // g++ -g `pkg-config --cflags --libs elementary-cxx efl-cxx eina-cxx eo-cxx ecore-cxx evas-cxx edje-cxx` button_cxx_example_00.cc -o button_cxx_example_00
 
 #define EFL_CXXPERIMENTAL
+#define EFL_BETA_API_SUPPORT
 #include <Elementary.hh>
 #include <iostream>
 

src/examples/elementary/button_cxx_example_01.cc

@@ -1,7 +1,7 @@
 // g++ -g `pkg-config --cflags --libs elementary-cxx efl-cxx eina-cxx eo-cxx ecore-cxx evas-cxx edje-cxx` button_cxx_example_01.cc -o button_cxx_example_01
 
 #define EFL_CXXPERIMENTAL
-#include <Efl_Ui.h>
+#define EFL_BETA_API_SUPPORT
 #include <Elementary.hh>
 
 using efl::eo::instantiate;

src/examples/elementary/radio_cxx_example_01.cc

@@ -1,7 +1,7 @@
 // g++ -g `pkg-config --cflags --libs elementary-cxx efl-cxx eina-cxx eo-cxx ecore-cxx evas-cxx edje-cxx` radio_cxx_example_01.cc -o radio_cxx_example_01
 
 #define EFL_CXXPERIMENTAL
-#include <Efl_Ui.h>
+#define EFL_BETA_API_SUPPORT
 #include <Elementary.hh>
 #include <iostream>
 

src/examples/elementary/slider_cxx_example.cc

@@ -1,8 +1,7 @@
 // g++ -g `pkg-config --cflags --libs elementary-cxx efl-cxx eina-cxx eo-cxx ecore-cxx evas-cxx edje-cxx` slider_cxx_example.cc -o slider_cxx_example
 
 #define EFL_CXXPERIMENTAL
-
-#include <Efl_Ui.h>
+#define EFL_BETA_API_SUPPORT
 #include <Elementary.hh>
 
 using namespace std::placeholders;

src/examples/elementary/toolbar_cxx_example_01.cc

@@ -7,7 +7,7 @@
 
 #warning This example requires yet unfinished EO APIs
 
-#include <Efl_Ui.h>
+#define EFL_BETA_API_SUPPORT
 #include <Elementary.hh>
 
 EAPI int

src/lib/eolian_cxx/grammar/function_declaration.hpp

@@ -44,8 +44,8 @@ struct function_declaration_generator
         }
 
       if(f.is_beta &&
-            !as_generator("#ifdef " << *(string << "_") << string << "_BETA\n")
-            .generate(sink, std::make_tuple(_klass_name.namespaces, _klass_name.eolian_name), add_upper_case_context(ctx)))
+            !as_generator(lit("#ifdef EFL_BETA_API_SUPPORT\n"))
+            .generate(sink, attributes::unused, ctx))
         return false;
       if(f.is_protected &&
             !as_generator("#ifdef " << *(string << "_") << string << "_PROTECTED\n")

src/lib/eolian_cxx/grammar/function_definition.hpp

@@ -50,8 +50,8 @@ struct function_definition_generator
         }
       
       if(f.is_beta &&
-         !as_generator("#ifdef " << *(string << "_") << string << "_BETA\n")
-         .generate(sink, std::make_tuple(_klass_name.namespaces, _klass_name.eolian_name), add_upper_case_context(ctx)))
+         !as_generator(lit("#ifdef EFL_BETA_API_SUPPORT\n"))
+         .generate(sink, attributes::unused, ctx))
         return false;
       if(f.is_protected &&
          !as_generator("#ifdef " << *(string << "_") << string << "_PROTECTED\n")