[Boost-sandbox-cvs] boost-sandbox/boost/units base_dimension.hpp, 1.3, 1.4

[Steven W. <ste...@us...>]

Update of /cvsroot/boost-sandbox/boost-sandbox/boost/units
In directory sc8-pr-cvs3.sourceforge.net:/tmp/cvs-serv29959/boost-sandbox/boost/units

Modified Files:
	base_dimension.hpp 
Log Message:
make sure that we can refer to base_dimension without causing erros

Index: base_dimension.hpp
===================================================================
RCS file: /cvsroot/boost-sandbox/boost-sandbox/boost/units/base_dimension.hpp,v
retrieving revision 1.3
retrieving revision 1.4
diff -u -d -r1.3 -r1.4
--- base_dimension.hpp	14 Apr 2007 21:52:00 -0000	1.3
+++ base_dimension.hpp	15 Apr 2007 01:41:48 -0000	1.4
@@ -41,10 +41,14 @@
 template<long N>
 struct long_ {};
 
+template<class T, long N>
+struct base_dimension_pair {};
+
 /// Again this needs to be in the same namespace as long_
+/// we need a mangled name because it must be found by ADL
 /// INTERNAL ONLY
-template<long N>
-no boost_units_prevent_double_definition(units::long_<N>) { return(no()); }
+template<class T>
+no boost_units_prevent_double_definition(const T&) { return(no()); }
 
 /// Defines a base dimensions.  To define a dimension you need to provide
 /// the derived class and a unique integer.
@@ -54,11 +58,13 @@
 template<class Derived,
          long N,
          class = typename ordinal_has_already_been_defined<
-             sizeof(boost_units_prevent_double_definition(units::long_<N>())) == sizeof(yes)
+             sizeof(boost_units_prevent_double_definition(units::long_<N>())) == sizeof(yes) &&
+             sizeof(boost_units_prevent_double_definition(units::base_dimension_pair<Derived, N>())) != sizeof(yes)
          >::type>
 struct base_dimension : mpl::long_<N> {
-    friend yes boost_units_prevent_double_definition(units::long_<N>) { return(yes()); }
-    typedef Derived this_type;
+    friend yes boost_units_prevent_double_definition(const units::long_<N>&) { return(yes()); }
+    friend yes boost_units_prevent_double_definition(const units::base_dimension_pair<Derived, N>&) { return(yes()); }
+    typedef base_dimension this_type;
     typedef mpl::long_<N> value;
     typedef dimension_list<dim<Derived,static_rational<1> >, dimensionless_type> type;
 };