boost/units/get_system.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_GET_SYSTEM_HPP
  12 #define BOOST_UNITS_GET_SYSTEM_HPP
  13
  14 #include <boost/units/units_fwd.hpp>
  15
  16 namespace boost {
  17
  18 namespace units {
  19
  20 template<class T>
  21 struct get_system {};
  22
  23 /// get the system of a unit
  24 template<class Dim,class System>
  25 struct get_system< unit<Dim,System> >
  26 {
  27     typedef System type;
  28 };
  29
  30 /// get the system of an absolute unit
  31 template<class Unit>
  32 struct get_system< absolute<Unit> >
  33 {
  34     typedef typename get_system<Unit>::type type;
  35 };
  36
  37 /// get the system of a quantity
  38 template<class Unit,class Y>
  39 struct get_system< quantity<Unit,Y> >
  40 {
  41     typedef typename get_system<Unit>::type     type;
  42 };
  43
  44 } // namespace units
  45
  46 } // namespace boost
  47
  48 #endif // BOOST_UNITS_GET_SYSTEM_HPP