boost/units/is_dimension_list.hpp

0001 // Boost.Units - A C++ library for zero-overhead dimensional analysis and
0002 // unit/quantity manipulation and conversion
0003 //
0004 // Copyright (C) 2003-2008 Matthias Christian Schabel
0005 // Copyright (C) 2008 Steven Watanabe
0006 //
0007 // Distributed under the Boost Software License, Version 1.0. (See
0008 // accompanying file LICENSE_1_0.txt or copy at
0009 // http://www.boost.org/LICENSE_1_0.txt)
0010
0011 #ifndef BOOST_UNITS_IS_DIMENSION_LIST_HPP
0012 #define BOOST_UNITS_IS_DIMENSION_LIST_HPP
0013
0014 ///
0015 /// \file
0016 /// \brief Check that a type is a valid dimension list.
0017 ///
0018
0019 #include <boost/mpl/bool.hpp>
0020
0021 #include <boost/units/units_fwd.hpp>
0022
0023 namespace boost {
0024
0025 namespace units {
0026
0027 /// Check that a type is a valid dimension list.
0028 template<typename Seq>
0029 struct is_dimension_list :
0030     public mpl::false_
0031 { };
0032
0033 template<typename Item, typename Next>
0034 struct is_dimension_list<list<Item, Next> > :
0035     public mpl::true_
0036 { };
0037
0038 template<>
0039 struct is_dimension_list<dimensionless_type> :
0040     public mpl::true_
0041 { };
0042
0043 } // namespace units
0044
0045 } // namespace boost
0046
0047 #endif // BOOST_UNITS_IS_DIMENSION_LIST_HPP