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 /// \file
15 /// \brief Get the system of a unit, absolute unit or quantity.
16 
17 #include <boost/units/units_fwd.hpp>
18 
19 namespace boost {
20 
21 namespace units {
22 
23 template<class T>
24 struct get_system {};
25 
26 /// Get the system of a unit.
27 template<class Dim,class System>
28 struct get_system< unit<Dim,System> >
29 {
30     typedef System type;
31 };
32 
33 /// Get the system of an absolute unit.
34 template<class Unit>
35 struct get_system< absolute<Unit> >
36 {
37     typedef typename get_system<Unit>::type type;
38 };
39 
40 /// Get the system of a quantity.
41 template<class Unit,class Y>
42 struct get_system< quantity<Unit,Y> >
43 {
44     typedef typename get_system<Unit>::type     type;
45 };
46 
47 } // namespace units
48 
49 } // namespace boost
50 
51 #endif // BOOST_UNITS_GET_SYSTEM_HPP
52