Chris@16: // Boost.Units - A C++ library for zero-overhead dimensional analysis and 
Chris@16: // unit/quantity manipulation and conversion
Chris@16: //
Chris@16: // Copyright (C) 2003-2008 Matthias Christian Schabel
Chris@16: // Copyright (C) 2007-2008 Steven Watanabe
Chris@16: //
Chris@16: // Distributed under the Boost Software License, Version 1.0. (See
Chris@16: // accompanying file LICENSE_1_0.txt or copy at
Chris@16: // http://www.boost.org/LICENSE_1_0.txt)
Chris@16: 
Chris@16: #ifndef BOOST_UNITS_DETAIL_PREVENT_REDEFINITION_HPP
Chris@16: #define BOOST_UNITS_DETAIL_PREVENT_REDEFINITION_HPP
Chris@16: 
Chris@16: #include <boost/mpl/long.hpp>
Chris@16: 
Chris@16: namespace boost {
Chris@16: 
Chris@16: namespace units {
Chris@16: 
Chris@16: namespace detail {
Chris@16: 
Chris@16: struct no { no() {} char dummy; };
Chris@16: struct yes { no dummy[2]; };
Chris@16: 
Chris@16: template<bool> struct ordinal_has_already_been_defined;
Chris@16: 
Chris@16: template<>
Chris@16: struct ordinal_has_already_been_defined<true>   { };
Chris@16: 
Chris@16: template<>
Chris@16: struct ordinal_has_already_been_defined<false>  { typedef void type; };
Chris@16: 
Chris@16: }
Chris@16: 
Chris@16: /// This must be in namespace boost::units so that ADL
Chris@16: /// will work.  we need a mangled name because it must
Chris@16: /// be found by ADL
Chris@16: /// INTERNAL ONLY
Chris@16: template<class T>
Chris@16: detail::no 
Chris@16: boost_units_is_registered(const T&) 
Chris@16: { detail::no result; return(result); }
Chris@16: 
Chris@16: /// INTERNAL ONLY
Chris@16: template<class T>
Chris@16: detail::no 
Chris@16: boost_units_unit_is_registered(const T&) 
Chris@16: { detail::no result; return(result); }
Chris@16: 
Chris@16: } // namespace units
Chris@16: 
Chris@16: } // namespace boost
Chris@16: 
Chris@16: #endif // BOOST_UNITS_PREVENT_ORDINAL_REDEFINITION_IMPL_HPP