1 // Copyright John Maddock 2007.
2 // Use, modification and distribution are subject to the
3 // Boost Software License, Version 1.0. (See accompanying file
4 // LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
5
6 #ifndef BOOST_MATH_TRUNC_HPP
7 #define BOOST_MATH_TRUNC_HPP
8
9 #ifdef _MSC_VER
10 #pragma once
11 #endif
12
13 #include <boost/math/special_functions/math_fwd.hpp>
14 #include <boost/math/tools/config.hpp>
15 #include <boost/math/policies/error_handling.hpp>
16 #include <boost/math/special_functions/fpclassify.hpp>
17 #include <boost/type_traits/is_constructible.hpp>
18 #include <boost/core/enable_if.hpp>
19
20 namespace boost{ namespace math{ namespace detail{
21
22 template <class T, class Policy>
trunc(const T & v,const Policy & pol,const boost::false_type &)23 inline typename tools::promote_args<T>::type trunc(const T& v, const Policy& pol, const boost::false_type&)
24 {
25 BOOST_MATH_STD_USING
26 typedef typename tools::promote_args<T>::type result_type;
27 if(!(boost::math::isfinite)(v))
28 return policies::raise_rounding_error("boost::math::trunc<%1%>(%1%)", 0, static_cast<result_type>(v), static_cast<result_type>(v), pol);
29 return (v >= 0) ? static_cast<result_type>(floor(v)) : static_cast<result_type>(ceil(v));
30 }
31
32 template <class T, class Policy>
trunc(const T & v,const Policy &,const boost::true_type &)33 inline typename tools::promote_args<T>::type trunc(const T& v, const Policy&, const boost::true_type&)
34 {
35 return v;
36 }
37
38 }
39
40 template <class T, class Policy>
trunc(const T & v,const Policy & pol)41 inline typename tools::promote_args<T>::type trunc(const T& v, const Policy& pol)
42 {
43 return detail::trunc(v, pol, boost::integral_constant<bool, detail::is_integer_for_rounding<T>::value>());
44 }
45 template <class T>
trunc(const T & v)46 inline typename tools::promote_args<T>::type trunc(const T& v)
47 {
48 return trunc(v, policies::policy<>());
49 }
50 //
51 // The following functions will not compile unless T has an
52 // implicit conversion to the integer types. For user-defined
53 // number types this will likely not be the case. In that case
54 // these functions should either be specialized for the UDT in
55 // question, or else overloads should be placed in the same
56 // namespace as the UDT: these will then be found via argument
57 // dependent lookup. See our concept archetypes for examples.
58 //
59 template <class T, class Policy>
itrunc(const T & v,const Policy & pol)60 inline int itrunc(const T& v, const Policy& pol)
61 {
62 BOOST_MATH_STD_USING
63 typedef typename tools::promote_args<T>::type result_type;
64 result_type r = boost::math::trunc(v, pol);
65 if((r > (std::numeric_limits<int>::max)()) || (r < (std::numeric_limits<int>::min)()))
66 return static_cast<int>(policies::raise_rounding_error("boost::math::itrunc<%1%>(%1%)", 0, static_cast<result_type>(v), 0, pol));
67 return static_cast<int>(r);
68 }
69 template <class T>
itrunc(const T & v)70 inline int itrunc(const T& v)
71 {
72 return itrunc(v, policies::policy<>());
73 }
74
75 template <class T, class Policy>
ltrunc(const T & v,const Policy & pol)76 inline long ltrunc(const T& v, const Policy& pol)
77 {
78 BOOST_MATH_STD_USING
79 typedef typename tools::promote_args<T>::type result_type;
80 result_type r = boost::math::trunc(v, pol);
81 if((r > (std::numeric_limits<long>::max)()) || (r < (std::numeric_limits<long>::min)()))
82 return static_cast<long>(policies::raise_rounding_error("boost::math::ltrunc<%1%>(%1%)", 0, static_cast<result_type>(v), 0L, pol));
83 return static_cast<long>(r);
84 }
85 template <class T>
ltrunc(const T & v)86 inline long ltrunc(const T& v)
87 {
88 return ltrunc(v, policies::policy<>());
89 }
90
91 #ifdef BOOST_HAS_LONG_LONG
92
93 template <class T, class Policy>
lltrunc(const T & v,const Policy & pol)94 inline boost::long_long_type lltrunc(const T& v, const Policy& pol)
95 {
96 BOOST_MATH_STD_USING
97 typedef typename tools::promote_args<T>::type result_type;
98 result_type r = boost::math::trunc(v, pol);
99 if((r > (std::numeric_limits<boost::long_long_type>::max)()) || (r < (std::numeric_limits<boost::long_long_type>::min)()))
100 return static_cast<boost::long_long_type>(policies::raise_rounding_error("boost::math::lltrunc<%1%>(%1%)", 0, v, static_cast<boost::long_long_type>(0), pol));
101 return static_cast<boost::long_long_type>(r);
102 }
103 template <class T>
lltrunc(const T & v)104 inline boost::long_long_type lltrunc(const T& v)
105 {
106 return lltrunc(v, policies::policy<>());
107 }
108
109 #endif
110
111 template <class T, class Policy>
112 inline typename boost::enable_if_c<boost::is_constructible<int, T>::value, int>::type
iconvert(const T & v,const Policy &)113 iconvert(const T& v, const Policy&)
114 {
115 return static_cast<int>(v);
116 }
117
118 template <class T, class Policy>
119 inline typename boost::disable_if_c<boost::is_constructible<int, T>::value, int>::type
iconvert(const T & v,const Policy & pol)120 iconvert(const T& v, const Policy& pol)
121 {
122 using boost::math::itrunc;
123 return itrunc(v, pol);
124 }
125
126 template <class T, class Policy>
127 inline typename boost::enable_if_c<boost::is_constructible<long, T>::value, long>::type
lconvert(const T & v,const Policy &)128 lconvert(const T& v, const Policy&)
129 {
130 return static_cast<long>(v);
131 }
132
133 template <class T, class Policy>
134 inline typename boost::disable_if_c<boost::is_constructible<long, T>::value, long>::type
lconvert(const T & v,const Policy & pol)135 lconvert(const T& v, const Policy& pol)
136 {
137 using boost::math::ltrunc;
138 return ltrunc(v, pol);
139 }
140
141 #ifdef BOOST_HAS_LONG_LONG
142
143 template <class T, class Policy>
144 inline typename boost::enable_if_c<boost::is_constructible<boost::long_long_type, T>::value, boost::long_long_type>::type
llconvertert(const T & v,const Policy &)145 llconvertert(const T& v, const Policy&)
146 {
147 return static_cast<boost::long_long_type>(v);
148 }
149
150 template <class T, class Policy>
151 inline typename boost::disable_if_c<boost::is_constructible<boost::long_long_type, T>::value, boost::long_long_type>::type
llconvertert(const T & v,const Policy & pol)152 llconvertert(const T& v, const Policy& pol)
153 {
154 using boost::math::lltrunc;
155 return lltrunc(v, pol);
156 }
157
158 #endif
159
160 }} // namespaces
161
162 #endif // BOOST_MATH_TRUNC_HPP
163