1 | /* Boost interval/constants.hpp template implementation file |
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2 | * |
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3 | * Copyright 2002 Hervé Brönnimann, Guillaume Melquiond, Sylvain Pion |
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4 | * |
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5 | * Distributed under the Boost Software License, Version 1.0. |
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6 | * (See accompanying file LICENSE_1_0.txt or |
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7 | * copy at http://www.boost.org/LICENSE_1_0.txt) |
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8 | */ |
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9 | |
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10 | #ifndef BOOST_NUMERIC_INTERVAL_CONSTANTS_HPP |
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11 | #define BOOST_NUMERIC_INTERVAL_CONSTANTS_HPP |
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12 | |
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13 | namespace boost { |
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14 | namespace numeric { |
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15 | namespace interval_lib { |
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16 | namespace constants { |
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17 | |
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18 | // These constants should be exactly computed. |
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19 | // Decimal representations wouldn't do it since the standard doesn't |
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20 | // specify the rounding (even nearest) that should be used. |
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21 | |
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22 | static const float pi_f_l = 13176794.0f/(1<<22); |
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23 | static const float pi_f_u = 13176795.0f/(1<<22); |
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24 | static const double pi_d_l = (3373259426.0 + 273688.0 / (1<<21)) / (1<<30); |
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25 | static const double pi_d_u = (3373259426.0 + 273689.0 / (1<<21)) / (1<<30); |
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26 | |
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27 | template<class T> inline T pi_lower() { return 3; } |
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28 | template<class T> inline T pi_upper() { return 4; } |
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29 | template<class T> inline T pi_half_lower() { return 1; } |
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30 | template<class T> inline T pi_half_upper() { return 2; } |
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31 | template<class T> inline T pi_twice_lower() { return 6; } |
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32 | template<class T> inline T pi_twice_upper() { return 7; } |
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33 | |
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34 | template<> inline float pi_lower<float>() { return pi_f_l; } |
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35 | template<> inline float pi_upper<float>() { return pi_f_u; } |
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36 | template<> inline float pi_half_lower<float>() { return pi_f_l / 2; } |
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37 | template<> inline float pi_half_upper<float>() { return pi_f_u / 2; } |
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38 | template<> inline float pi_twice_lower<float>() { return pi_f_l * 2; } |
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39 | template<> inline float pi_twice_upper<float>() { return pi_f_u * 2; } |
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40 | |
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41 | template<> inline double pi_lower<double>() { return pi_d_l; } |
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42 | template<> inline double pi_upper<double>() { return pi_d_u; } |
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43 | template<> inline double pi_half_lower<double>() { return pi_d_l / 2; } |
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44 | template<> inline double pi_half_upper<double>() { return pi_d_u / 2; } |
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45 | template<> inline double pi_twice_lower<double>() { return pi_d_l * 2; } |
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46 | template<> inline double pi_twice_upper<double>() { return pi_d_u * 2; } |
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47 | |
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48 | template<> inline long double pi_lower<long double>() { return pi_d_l; } |
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49 | template<> inline long double pi_upper<long double>() { return pi_d_u; } |
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50 | template<> inline long double pi_half_lower<long double>() { return pi_d_l / 2; } |
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51 | template<> inline long double pi_half_upper<long double>() { return pi_d_u / 2; } |
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52 | template<> inline long double pi_twice_lower<long double>() { return pi_d_l * 2; } |
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53 | template<> inline long double pi_twice_upper<long double>() { return pi_d_u * 2; } |
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54 | |
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55 | } // namespace constants |
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56 | |
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57 | template<class I> inline |
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58 | I pi() |
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59 | { |
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60 | typedef typename I::base_type T; |
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61 | return I(constants::pi_lower<T>(), |
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62 | constants::pi_upper<T>(), true); |
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63 | } |
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64 | |
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65 | template<class I> inline |
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66 | I pi_half() |
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67 | { |
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68 | typedef typename I::base_type T; |
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69 | return I(constants::pi_half_lower<T>(), |
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70 | constants::pi_half_upper<T>(), true); |
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71 | } |
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72 | |
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73 | template<class I> inline |
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74 | I pi_twice() |
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75 | { |
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76 | typedef typename I::base_type T; |
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77 | return I(constants::pi_twice_lower<T>(), |
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78 | constants::pi_twice_upper<T>(), true); |
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79 | } |
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80 | |
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81 | } // namespace interval_lib |
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82 | } // namespace numeric |
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83 | } // namespace boost |
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84 | |
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85 | #endif // BOOST_NUMERIC_INTERVAL_CONSTANTS_HPP |
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