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