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/type_traits/is_integral.hpp> |
15 | |
16 | #include <boost/units/operators.hpp> |
17 | #include <boost/units/static_rational.hpp> |
18 | #include <boost/units/detail/static_rational_power.hpp> |
19 | |
20 | /// \file |
21 | /// \brief Raise values to exponents known at compile-time. |
22 | |
23 | namespace boost { |
24 | |
25 | namespace units { |
26 | |
27 | /// raise a value to a @c static_rational power. |
28 | template<class Rat,class Y> |
29 | BOOST_CONSTEXPR |
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 | BOOST_CONSTEXPR |
39 | inline typename power_typeof_helper<Y,static_rational<N> >::type |
40 | pow(const Y& x) |
41 | { |
42 | return power_typeof_helper<Y,static_rational<N> >::value(x); |
43 | } |
44 | |
45 | #ifndef BOOST_UNITS_DOXYGEN |
46 | |
47 | /// raise @c T to a @c static_rational power. |
48 | template<class T, long N,long D> |
49 | struct power_typeof_helper<T, static_rational<N,D> > |
50 | { |
51 | typedef typename mpl::if_<boost::is_integral<T>, double, T>::type internal_type; |
52 | typedef detail::static_rational_power_impl<static_rational<N, D>, internal_type> impl; |
53 | typedef typename impl::type type; |
54 | |
55 | static BOOST_CONSTEXPR type value(const T& x) |
56 | { |
57 | return impl::call(x); |
58 | } |
59 | }; |
60 | |
61 | /// raise @c float to a @c static_rational power. |
62 | template<long N,long D> |
63 | struct power_typeof_helper<float, static_rational<N,D> > |
64 | { |
65 | // N.B. pathscale doesn't accept inheritance for some reason. |
66 | typedef power_typeof_helper<double, static_rational<N,D> > base; |
67 | typedef typename base::type type; |
68 | static BOOST_CONSTEXPR type value(const double& x) |
69 | { |
70 | return base::value(x); |
71 | } |
72 | }; |
73 | |
74 | #endif |
75 | |
76 | /// take the @c static_rational root of a value. |
77 | template<class Rat,class Y> |
78 | BOOST_CONSTEXPR |
79 | typename root_typeof_helper<Y,Rat>::type |
80 | root(const Y& x) |
81 | { |
82 | return root_typeof_helper<Y,Rat>::value(x); |
83 | } |
84 | |
85 | /// take the integer root of a value. |
86 | template<long N,class Y> |
87 | BOOST_CONSTEXPR |
88 | typename root_typeof_helper<Y,static_rational<N> >::type |
89 | root(const Y& x) |
90 | { |
91 | return root_typeof_helper<Y,static_rational<N> >::value(x); |
92 | } |
93 | |
94 | #ifndef BOOST_UNITS_DOXYGEN |
95 | |
96 | /// take @c static_rational root of an @c T |
97 | template<class T, long N,long D> |
98 | struct root_typeof_helper<T,static_rational<N,D> > |
99 | { |
100 | // N.B. pathscale doesn't accept inheritance for some reason. |
101 | typedef power_typeof_helper<T, static_rational<D,N> > base; |
102 | typedef typename base::type type; |
103 | static BOOST_CONSTEXPR type value(const T& x) |
104 | { |
105 | return(base::value(x)); |
106 | } |
107 | }; |
108 | |
109 | #endif |
110 | |
111 | } // namespace units |
112 | |
113 | } // namespace boost |
114 | |
115 | #endif // BOOST_UNITS_STATIC_RATIONAL_HPP |
116 | |