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_POW_HPP |
12 | #define BOOST_UNITS_POW_HPP |
13 | |
14 | #include <boost/math_fwd.hpp> |
15 | #include <boost/type_traits/is_integral.hpp> |
16 | |
17 | #include <boost/units/operators.hpp> |
18 | #include <boost/units/static_rational.hpp> |
19 | #include <boost/units/detail/static_rational_power.hpp> |
20 | |
21 | /// \file |
22 | /// \brief Raise values to exponents known at compile-time. |
23 | |
24 | namespace boost { |
25 | |
26 | namespace units { |
27 | |
28 | /// raise a value to a @c static_rational power. |
29 | template<class Rat,class Y> |
30 | inline typename power_typeof_helper<Y,Rat>::type |
31 | pow(const Y& x) |
32 | { |
33 | return power_typeof_helper<Y,Rat>::value(x); |
34 | } |
35 | |
36 | /// raise a value to an integer power. |
37 | template<long N,class Y> |
38 | inline typename power_typeof_helper<Y,static_rational<N> >::type |
39 | pow(const Y& x) |
40 | { |
41 | return power_typeof_helper<Y,static_rational<N> >::value(x); |
42 | } |
43 | |
44 | #ifndef BOOST_UNITS_DOXYGEN |
45 | |
46 | /// raise @c T to a @c static_rational power. |
47 | template<class T, long N,long D> |
48 | struct power_typeof_helper<T, static_rational<N,D> > |
49 | { |
50 | typedef typename mpl::if_<boost::is_integral<T>, double, T>::type internal_type; |
51 | typedef detail::static_rational_power_impl<static_rational<N, D>, internal_type> impl; |
52 | typedef typename impl::type type; |
53 | |
54 | static type value(const T& x) |
55 | { |
56 | return impl::call(x); |
57 | } |
58 | }; |
59 | |
60 | /// raise @c float to a @c static_rational power. |
61 | template<long N,long D> |
62 | struct power_typeof_helper<float, static_rational<N,D> > |
63 | { |
64 | // N.B. pathscale doesn't accept inheritance for some reason. |
65 | typedef power_typeof_helper<double, static_rational<N,D> > base; |
66 | typedef typename base::type type; |
67 | static type value(const double& x) |
68 | { |
69 | return base::value(x); |
70 | } |
71 | }; |
72 | |
73 | #endif |
74 | |
75 | /// take the @c static_rational root of a value. |
76 | template<class Rat,class Y> |
77 | typename root_typeof_helper<Y,Rat>::type |
78 | root(const Y& x) |
79 | { |
80 | return root_typeof_helper<Y,Rat>::value(x); |
81 | } |
82 | |
83 | /// take the integer root of a value. |
84 | template<long N,class Y> |
85 | typename root_typeof_helper<Y,static_rational<N> >::type |
86 | root(const Y& x) |
87 | { |
88 | return root_typeof_helper<Y,static_rational<N> >::value(x); |
89 | } |
90 | |
91 | #ifndef BOOST_UNITS_DOXYGEN |
92 | |
93 | /// take @c static_rational root of an @c T |
94 | template<class T, long N,long D> |
95 | struct root_typeof_helper<T,static_rational<N,D> > |
96 | { |
97 | // N.B. pathscale doesn't accept inheritance for some reason. |
98 | typedef power_typeof_helper<T, static_rational<D,N> > base; |
99 | typedef typename base::type type; |
100 | static type value(const T& x) |
101 | { |
102 | return(base::value(x)); |
103 | } |
104 | }; |
105 | |
106 | #endif |
107 | |
108 | } // namespace units |
109 | |
110 | } // namespace boost |
111 | |
112 | #endif // BOOST_UNITS_STATIC_RATIONAL_HPP |
113 | |