From 4f63c3f8a868d54ce4f8cd682591b4c68013b7a8 Mon Sep 17 00:00:00 2001
From: Thomas Geymayer <tomgey@gmail.com>
Date: Wed, 15 Nov 2017 19:31:29 +0100
Subject: [PATCH] nasal::Object: Simplify with C++11

C++11 variadic templates finally allow us to get rid of the
ugly boost preprocessor workaround.
---
 simgear/nasal/cppbind/CMakeLists.txt          |  1 -
 simgear/nasal/cppbind/NasalObject.hxx         | 24 +++++++------
 .../NasalObject_callMethod_templates.hxx      | 35 -------------------
 3 files changed, 14 insertions(+), 46 deletions(-)
 delete mode 100644 simgear/nasal/cppbind/detail/NasalObject_callMethod_templates.hxx

diff --git a/simgear/nasal/cppbind/CMakeLists.txt b/simgear/nasal/cppbind/CMakeLists.txt
index 9d005394..5ef4a5aa 100644
--- a/simgear/nasal/cppbind/CMakeLists.txt
+++ b/simgear/nasal/cppbind/CMakeLists.txt
@@ -17,7 +17,6 @@ set(DETAIL_HEADERS
   detail/from_nasal_helper.hxx
   detail/functor_templates.hxx
   detail/nasal_traits.hxx
-  detail/NasalObject_callMethod_templates.hxx
   detail/to_nasal_helper.hxx
 )
 
diff --git a/simgear/nasal/cppbind/NasalObject.hxx b/simgear/nasal/cppbind/NasalObject.hxx
index 05543254..565c1670 100644
--- a/simgear/nasal/cppbind/NasalObject.hxx
+++ b/simgear/nasal/cppbind/NasalObject.hxx
@@ -23,9 +23,6 @@
 #include "NasalObjectHolder.hxx"
 #include "Ghost.hxx"
 
-#include <boost/preprocessor/iteration/iterate.hpp>
-#include <boost/preprocessor/repetition/enum_trailing_binary_params.hpp>
-
 namespace nasal
 {
   /**
@@ -48,14 +45,21 @@ namespace nasal
 
       bool valid() const;
 
-      // Build dependency for CMake, gcc, etc.
-#define SG_DONT_DO_ANYTHING
-# include <simgear/nasal/cppbind/detail/NasalObject_callMethod_templates.hxx>
-#undef SG_DONT_DO_ANYTHING
+      template<class Ret, class ... Args>
+      Ret callMethod(const std::string& name, Args ... args)
+      {
+        if( !_nasal_impl.valid() )
+          return Ret();
 
-#define BOOST_PP_ITERATION_LIMITS (0, 9)
-#define BOOST_PP_FILENAME_1 <simgear/nasal/cppbind/detail/NasalObject_callMethod_templates.hxx>
-#include BOOST_PP_ITERATE()
+        Context ctx;
+        auto func = get_member<boost::function<Ret (nasal::Me, Args...)>>(
+          ctx, _nasal_impl.get_naRef(), name
+        );
+        if( func )
+          return func(nasal::to_nasal(ctx, this), args...);
+
+        return Ret();
+      }
 
       bool _set(naContext c, const std::string& key, naRef val);
       bool _get(naContext c, const std::string& key, naRef& out);
diff --git a/simgear/nasal/cppbind/detail/NasalObject_callMethod_templates.hxx b/simgear/nasal/cppbind/detail/NasalObject_callMethod_templates.hxx
deleted file mode 100644
index 41dd9fd4..00000000
--- a/simgear/nasal/cppbind/detail/NasalObject_callMethod_templates.hxx
+++ /dev/null
@@ -1,35 +0,0 @@
-#ifndef SG_NASAL_OBJECT_HXX_
-# error Nasal cppbind - do not include this file!
-#endif
-
-#ifndef SG_DONT_DO_ANYTHING
-#define n BOOST_PP_ITERATION()
-
-#define SG_CALL_ARG(z, n, dummy)\
-      to_nasal<typename boost::call_traits<A##n>::param_type>(ctx, a##n)
-
-  template<
-    class Ret
-    BOOST_PP_ENUM_TRAILING_PARAMS(n, class A)
-  >
-  Ret callMethod( const std::string& name
-                  BOOST_PP_ENUM_TRAILING_BINARY_PARAMS(n, A, a) )
-  {
-    if( !_nasal_impl.valid() )
-      return Ret();
-
-    typedef boost::function<Ret (nasal::Me BOOST_PP_ENUM_TRAILING_PARAMS(n, A))>
-            MemFunc;
-
-    Context ctx;
-    MemFunc f = get_member<MemFunc>(ctx, _nasal_impl.get_naRef(), name.c_str());
-    if( f )
-      return f(nasal::to_nasal(ctx, this) BOOST_PP_ENUM_TRAILING_PARAMS(n, a));
-
-    return Ret();
-  }
-
-#undef SG_CALL_ARG
-
-#undef n
-#endif // SG_DONT_DO_ANYTHING