1 /* Boost interval/rounded_arith.hpp template implementation file
3 * Copyright 2002-2003 Hervé Brönnimann, Guillaume Melquiond, Sylvain Pion
5 * Distributed under the Boost Software License, Version 1.0.
6 * (See accompanying file LICENSE_1_0.txt or
7 * copy at http://www.boost.org/LICENSE_1_0.txt)
10 #ifndef BOOST_NUMERIC_INTERVAL_ROUNDED_ARITH_HPP
11 #define BOOST_NUMERIC_INTERVAL_ROUNDED_ARITH_HPP
13 #include <boost/numeric/interval/rounding.hpp>
14 #include <boost/numeric/interval/detail/bugs.hpp>
15 #include <boost/config/no_tr1/cmath.hpp>
19 namespace interval_lib {
22 * Three classes of rounding: exact, std, opp
23 * See documentation for details.
26 template<class T, class Rounding>
27 struct rounded_arith_exact: Rounding {
29 template<class U> T conv_down(U const &v) { return v; }
30 template<class U> T conv_up (U const &v) { return v; }
31 T add_down (const T& x, const T& y) { return x + y; }
32 T add_up (const T& x, const T& y) { return x + y; }
33 T sub_down (const T& x, const T& y) { return x - y; }
34 T sub_up (const T& x, const T& y) { return x - y; }
35 T mul_down (const T& x, const T& y) { return x * y; }
36 T mul_up (const T& x, const T& y) { return x * y; }
37 T div_down (const T& x, const T& y) { return x / y; }
38 T div_up (const T& x, const T& y) { return x / y; }
39 T median (const T& x, const T& y) { return (x + y) / 2; }
40 T sqrt_down(const T& x)
41 { BOOST_NUMERIC_INTERVAL_using_math(sqrt); return sqrt(x); }
42 T sqrt_up (const T& x)
43 { BOOST_NUMERIC_INTERVAL_using_math(sqrt); return sqrt(x); }
44 T int_down (const T& x)
45 { BOOST_NUMERIC_INTERVAL_using_math(floor); return floor(x); }
47 { BOOST_NUMERIC_INTERVAL_using_math(ceil); return ceil(x); }
50 template<class T, class Rounding>
51 struct rounded_arith_std: Rounding {
52 # define BOOST_DN(EXPR) this->downward(); return this->force_rounding(EXPR)
53 # define BOOST_NR(EXPR) this->to_nearest(); return this->force_rounding(EXPR)
54 # define BOOST_UP(EXPR) this->upward(); return this->force_rounding(EXPR)
56 template<class U> T conv_down(U const &v) { BOOST_DN(v); }
57 template<class U> T conv_up (U const &v) { BOOST_UP(v); }
58 T add_down(const T& x, const T& y) { BOOST_DN(x + y); }
59 T sub_down(const T& x, const T& y) { BOOST_DN(x - y); }
60 T mul_down(const T& x, const T& y) { BOOST_DN(x * y); }
61 T div_down(const T& x, const T& y) { BOOST_DN(x / y); }
62 T add_up (const T& x, const T& y) { BOOST_UP(x + y); }
63 T sub_up (const T& x, const T& y) { BOOST_UP(x - y); }
64 T mul_up (const T& x, const T& y) { BOOST_UP(x * y); }
65 T div_up (const T& x, const T& y) { BOOST_UP(x / y); }
66 T median(const T& x, const T& y) { BOOST_NR((x + y) / 2); }
67 T sqrt_down(const T& x)
68 { BOOST_NUMERIC_INTERVAL_using_math(sqrt); BOOST_DN(sqrt(x)); }
69 T sqrt_up (const T& x)
70 { BOOST_NUMERIC_INTERVAL_using_math(sqrt); BOOST_UP(sqrt(x)); }
71 T int_down(const T& x) { this->downward(); return to_int(x); }
72 T int_up (const T& x) { this->upward(); return to_int(x); }
78 template<class T, class Rounding>
79 struct rounded_arith_opp: Rounding {
80 void init() { this->upward(); }
81 # define BOOST_DN(EXPR) \
83 T r = this->force_rounding(EXPR); \
86 # define BOOST_NR(EXPR) \
88 T r = this->force_rounding(EXPR); \
91 # define BOOST_UP(EXPR) return this->force_rounding(EXPR)
92 # define BOOST_UP_NEG(EXPR) return -this->force_rounding(EXPR)
93 template<class U> T conv_down(U const &v) { BOOST_UP_NEG(-v); }
94 template<class U> T conv_up (U const &v) { BOOST_UP(v); }
95 T add_down(const T& x, const T& y) { BOOST_UP_NEG((-x) - y); }
96 T sub_down(const T& x, const T& y) { BOOST_UP_NEG(y - x); }
97 T mul_down(const T& x, const T& y) { BOOST_UP_NEG(x * (-y)); }
98 T div_down(const T& x, const T& y) { BOOST_UP_NEG(x / (-y)); }
99 T add_up (const T& x, const T& y) { BOOST_UP(x + y); }
100 T sub_up (const T& x, const T& y) { BOOST_UP(x - y); }
101 T mul_up (const T& x, const T& y) { BOOST_UP(x * y); }
102 T div_up (const T& x, const T& y) { BOOST_UP(x / y); }
103 T median (const T& x, const T& y) { BOOST_NR((x + y) / 2); }
104 T sqrt_down(const T& x)
105 { BOOST_NUMERIC_INTERVAL_using_math(sqrt); BOOST_DN(sqrt(x)); }
106 T sqrt_up (const T& x)
107 { BOOST_NUMERIC_INTERVAL_using_math(sqrt); BOOST_UP(sqrt(x)); }
108 T int_down(const T& x) { return -to_int(-x); }
109 T int_up (const T& x) { return to_int(x); }
116 } // namespace interval_lib
117 } // namespace numeric
120 #endif // BOOST_NUMERIC_INTERVAL_ROUNDED_ARITH_HPP