boost/units/is_dimension_list.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) 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_IS_DIMENSION_LIST_HPP
  12 #define BOOST_UNITS_IS_DIMENSION_LIST_HPP
  13
  14 #include <boost/mpl/bool.hpp>
  15
  16 #include <boost/units/units_fwd.hpp>
  17
  18 namespace boost {
  19
  20 namespace units {
  21
  22 /// Check that a type is a valid dimension list.
  23 template<typename Seq>
  24 struct is_dimension_list :
  25     public mpl::false_
  26 { };
  27
  28 template<typename Item, typename Next>
  29 struct is_dimension_list<list<Item, Next> > :
  30     public mpl::true_
  31 { };
  32
  33 template<>
  34 struct is_dimension_list<dimensionless_type> :
  35     public mpl::true_
  36 { };
  37
  38 } // namespace units
  39
  40 } // namespace boost
  41
  42 #endif // BOOST_UNITS_IS_DIMENSION_LIST_HPP