function_base.hpp:

function_template.hpp:
  - Revert to older implementation of has_empty_function (Metrowerks doesn't
    handle is_base_and_derived correctly)


[SVN r13854]

include/boost/function/function_base.hpp

@@ -341,20 +341,14 @@ namespace boost {
 
   namespace detail {
     namespace function {
-      // The result is not a Boost.Function object, so we assume that this
+      inline bool has_empty_target(const function_base* f)
-      // target is not empty
-      template<typename FunctionObj>
-      inline bool has_empty_target(const FunctionObj&, truth<false>)
       {
-	return false;
+        return f->empty();
       }
 
-      // The result is a Boost.Function object, so query whether it is empty
+      inline bool has_empty_target(...)
-      // or not
+      {
-      template<typename FunctionObj>
+        return false;
-      inline bool has_empty_target(const FunctionObj& f, truth<true>)
-      { 
-        return f.empty();
       }
     } // end namespace function
   } // end namespace detail

include/boost/function/function_template.hpp

@@ -425,11 +425,7 @@ namespace boost {
     template<typename FunctionObj>
     void assign_to(FunctionObj f, detail::function::function_obj_tag)
     {
-      typedef detail::function::truth<
+      if (!detail::function::has_empty_target(addressof(f))) {
-                boost::is_base_and_derived<function_base, FunctionObj>::value>
-	is_boost_function;
-
-      if (!detail::function::has_empty_target(f, is_boost_function())) {
         typedef 
           typename detail::function::BOOST_FUNCTION_GET_FUNCTION_OBJ_INVOKER<
                                        FunctionObj,
@@ -463,11 +459,7 @@ namespace boost {
     void assign_to(const reference_wrapper<FunctionObj>& f, 
                    detail::function::function_obj_ref_tag)
     {
-      typedef detail::function::truth<
+      if (!detail::function::has_empty_target(f.get_pointer())) {
-                boost::is_base_and_derived<function_base, FunctionObj>::value>
-	is_boost_function;
-
-      if (!detail::function::has_empty_target(f.get(), is_boost_function())) {
         typedef 
           typename detail::function::BOOST_FUNCTION_GET_FUNCTION_OBJ_INVOKER<
                                        FunctionObj,