Improve Python 2.x compatibility.

Author: nascheme

include/boost/python/module_init.hpp

@@ -127,15 +127,15 @@ BOOST_PYTHON_DECL PyObject* init_module(char const* name, void(*)());
 
 #  endif
 
-#  ifdef HAS_CXX11
+#  if defined(HAS_CXX11) && (PY_VERSION_HEX >= 0x03000000)
 #   define BOOST_PYTHON_MODULE_INIT(name, ...)                  \
   void BOOST_PP_CAT(init_module_,name)();                      \
 extern "C" BOOST_SYMBOL_EXPORT _BOOST_PYTHON_MODULE_INIT(name, __VA_ARGS__)
 #  else
 #   define BOOST_PYTHON_MODULE_INIT(name)                       \
   void BOOST_PP_CAT(init_module_,name)();                      \
 extern "C" BOOST_SYMBOL_EXPORT _BOOST_PYTHON_MODULE_INIT(name)
-#  endif // HAS_CXX11
+#  endif // HAS_CXX11 && Python 3
 
 # endif
 

test/module_nogil.cpp

@@ -8,15 +8,15 @@ int get_value() {
     return 1234;
 }
 
-#ifdef HAS_CXX11
-// C++11 build: test with mod_gil_not_used option
+#if defined(HAS_CXX11) && (PY_VERSION_HEX >= 0x03000000)
+// C++11 build with Python 3: test with mod_gil_not_used option
 BOOST_PYTHON_MODULE(module_nogil_ext, boost::python::mod_gil_not_used())
 {
     using namespace boost::python;
     def("get_value", get_value);
 }
 #else
-// C++98 build: test without optional arguments
+// C++98 build or Python 2: test without optional arguments
 BOOST_PYTHON_MODULE(module_nogil_ext)
 {
     using namespace boost::python;