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 #include <boost/type_traits/is_same.hpp>
12 #include <boost/mpl/assert.hpp>
13
14 #include <boost/units/base_unit.hpp>
15 #include <boost/units/derived_dimension.hpp>
16 #include <boost/units/make_system.hpp>
17 #include <boost/units/operators.hpp>
18 #include <boost/units/reduce_unit.hpp>
19 #include <boost/units/unit.hpp>
20
21 #include <boost/units/physical_dimensions/current.hpp>
22 #include <boost/units/physical_dimensions/electric_potential.hpp>
23 #include <boost/units/physical_dimensions/energy.hpp>
24 #include <boost/units/physical_dimensions/force.hpp>
25 #include <boost/units/physical_dimensions/length.hpp>
26 #include <boost/units/physical_dimensions/mass.hpp>
27 #include <boost/units/physical_dimensions/time.hpp>
28
29 namespace test_system1 {
30
31 // the base units in the system will be:
32 //
33 // volts = m^2 kg s^-2 C^-1
34 // newtons = m kg s^-2
35 // joules = m^2 kg s^-2
36
37 // we will find the representation of m^-1 C^-1 = V N J^-2 = m^-1 C^-1
38
39 // reducing the system should generate the matrix equation
40 // 2 1 2
41 // 1 1 1 x = c
42 // -2 -2 -2
43 // -1 0 0
44
45 struct volt : boost::units::base_unit<volt, boost::units::electric_potential_dimension, 1> {};
46 struct newton : boost::units::base_unit<newton, boost::units::force_dimension, 2> {};
47 struct joule : boost::units::base_unit<joule, boost::units::energy_dimension, 3> {};
48
49 typedef boost::units::make_system<volt, newton, joule>::type complicated_system;
50
51 typedef boost::units::derived_dimension<
52 boost::units::length_base_dimension, -1,
53 boost::units::time_base_dimension, -1,
54 boost::units::current_base_dimension, -1
55 >::type dimension;
56
57 typedef boost::units::reduce_unit<boost::units::unit<dimension, complicated_system> >::type reduced;
58
59 typedef boost::units::divide_typeof_helper<
60 boost::units::multiply_typeof_helper<volt::unit_type, newton::unit_type>::type,
61 boost::units::power_typeof_helper<joule::unit_type, boost::units::static_rational<2> >::type
62 >::type expected;
63
test()64 void test() {
65 BOOST_MPL_ASSERT((boost::is_same<reduced, expected>));
66 }
67
68 }
69
70 namespace test_system2 {
71
72 // the base units in the system will be:
73 //
74 // kilograms = kg
75 // meters = m
76
77 // we will find the representation of m and kg
78
79 // reducing the system should generate the matrix equation
80 // 0 1
81 // 1 0 x = c
82
83 struct kilogram : boost::units::base_unit<kilogram, boost::units::mass_dimension, 4> {};
84 struct meter : boost::units::base_unit<meter, boost::units::length_dimension, 5> {};
85
86 typedef boost::units::make_system<meter, kilogram>::type mk_system;
87
88 typedef boost::units::reduce_unit<boost::units::unit<boost::units::mass_dimension, mk_system> >::type mass_unit;
89 typedef boost::units::reduce_unit<boost::units::unit<boost::units::length_dimension, mk_system> >::type length_unit;
90
test()91 void test() {
92 BOOST_MPL_ASSERT((boost::is_same<mass_unit, kilogram::unit_type>));
93 BOOST_MPL_ASSERT((boost::is_same<length_unit, meter::unit_type>));
94 }
95
96 }
97