ceph/src/boost/boost/units/detail/prevent_redefinition.hpp

   1 // Boost.Units - A C++ library for zero-overhead dimensional analysis and
   2 // unit/quantity manipulation and conversion
   3 //
   4 // Copyright (C) 2003-2008 Matthias Christian Schabel
   5 // Copyright (C) 2007-2008 Steven Watanabe
   6 //
   7 // Distributed under the Boost Software License, Version 1.0. (See
   8 // accompanying file LICENSE_1_0.txt or copy at
   9 // http://www.boost.org/LICENSE_1_0.txt)
  10
  11 #ifndef BOOST_UNITS_DETAIL_PREVENT_REDEFINITION_HPP
  12 #define BOOST_UNITS_DETAIL_PREVENT_REDEFINITION_HPP
  13
  14 #include <boost/mpl/long.hpp>
  15
  16 namespace boost {
  17
  18 namespace units {
  19
  20 namespace detail {
  21
  22 struct no { no() {} char dummy; };
  23 struct yes { no dummy[2]; };
  24
  25 template<bool> struct ordinal_has_already_been_defined;
  26
  27 template<>
  28 struct ordinal_has_already_been_defined<true>   { };
  29
  30 template<>
  31 struct ordinal_has_already_been_defined<false>  { typedef void type; };
  32
  33 }
  34
  35 /// This must be in namespace boost::units so that ADL
  36 /// will work.  we need a mangled name because it must
  37 /// be found by ADL
  38 /// INTERNAL ONLY
  39 template<class T>
  40 detail::no
  41 boost_units_is_registered(const T&)
  42 { detail::no result; return(result); }
  43
  44 /// INTERNAL ONLY
  45 template<class T>
  46 detail::no
  47 boost_units_unit_is_registered(const T&)
  48 { detail::no result; return(result); }
  49
  50 } // namespace units
  51
  52 } // namespace boost
  53
  54 #endif // BOOST_UNITS_PREVENT_ORDINAL_REDEFINITION_IMPL_HPP