1 // Copyright John Maddock 2010.
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 #ifdef _MSC_VER
7 # pragma once
8 #endif
9
10 #ifndef BOOST_MATH_CONSTANTS_INFO_INCLUDED
11 #define BOOST_MATH_CONSTANTS_INFO_INCLUDED
12
13 #include <boost/math/constants/constants.hpp>
14 #include <iostream>
15 #include <iomanip>
16 #include <typeinfo>
17
18 namespace boost{ namespace math{ namespace constants{
19
20 namespace detail{
21
22 template <class T>
nameof(BOOST_MATH_EXPLICIT_TEMPLATE_TYPE_SPEC (T))23 const char* nameof(BOOST_MATH_EXPLICIT_TEMPLATE_TYPE_SPEC(T))
24 {
25 return typeid(T).name();
26 }
27 template <>
nameof(BOOST_MATH_EXPLICIT_TEMPLATE_TYPE_SPEC (float))28 const char* nameof<float>(BOOST_MATH_EXPLICIT_TEMPLATE_TYPE_SPEC(float))
29 {
30 return "float";
31 }
32 template <>
nameof(BOOST_MATH_EXPLICIT_TEMPLATE_TYPE_SPEC (double))33 const char* nameof<double>(BOOST_MATH_EXPLICIT_TEMPLATE_TYPE_SPEC(double))
34 {
35 return "double";
36 }
37 template <>
nameof(BOOST_MATH_EXPLICIT_TEMPLATE_TYPE_SPEC (long double))38 const char* nameof<long double>(BOOST_MATH_EXPLICIT_TEMPLATE_TYPE_SPEC(long double))
39 {
40 return "long double";
41 }
42
43 }
44
45 template <class T, class Policy>
print_info_on_type(std::ostream & os=std::cout BOOST_MATH_APPEND_EXPLICIT_TEMPLATE_TYPE_SPEC (T)BOOST_MATH_APPEND_EXPLICIT_TEMPLATE_TYPE_SPEC (Policy))46 void print_info_on_type(std::ostream& os = std::cout BOOST_MATH_APPEND_EXPLICIT_TEMPLATE_TYPE_SPEC(T) BOOST_MATH_APPEND_EXPLICIT_TEMPLATE_TYPE_SPEC(Policy))
47 {
48 using detail::nameof;
49 #ifdef BOOST_MSVC
50 #pragma warning(push)
51 #pragma warning(disable:4127)
52 #endif
53 os <<
54 "Information on the Implementation and Handling of \n"
55 "Mathematical Constants for Type " << nameof<T>() <<
56 "\n\n"
57 "Checking for std::numeric_limits<" << nameof<T>() << "> specialisation: " <<
58 (std::numeric_limits<T>::is_specialized ? "yes" : "no") << std::endl;
59 if(std::numeric_limits<T>::is_specialized)
60 {
61 os <<
62 "std::numeric_limits<" << nameof<T>() << ">::digits reports that the radix is " << std::numeric_limits<T>::radix << ".\n";
63 if (std::numeric_limits<T>::radix == 2)
64 {
65 os <<
66 "std::numeric_limits<" << nameof<T>() << ">::digits reports that the precision is \n" << std::numeric_limits<T>::digits << " binary digits.\n";
67 }
68 else if (std::numeric_limits<T>::radix == 10)
69 {
70 os <<
71 "std::numeric_limits<" << nameof<T>() << ">::digits reports that the precision is \n" << std::numeric_limits<T>::digits10 << " decimal digits.\n";
72 os <<
73 "std::numeric_limits<" << nameof<T>() << ">::digits reports that the precision is \n"
74 << std::numeric_limits<T>::digits * 1000L /301L << " binary digits.\n"; // divide by log2(10) - about 3 bits per decimal digit.
75 }
76 else
77 {
78 os << "Unknown radix = " << std::numeric_limits<T>::radix << "\n";
79 }
80 }
81 typedef typename boost::math::policies::precision<T, Policy>::type precision_type;
82 if(precision_type::value)
83 {
84 if (std::numeric_limits<T>::radix == 2)
85 {
86 os <<
87 "boost::math::policies::precision<" << nameof<T>() << ", " << nameof<Policy>() << " reports that the compile time precision is \n" << precision_type::value << " binary digits.\n";
88 }
89 else if (std::numeric_limits<T>::radix == 10)
90 {
91 os <<
92 "boost::math::policies::precision<" << nameof<T>() << ", " << nameof<Policy>() << " reports that the compile time precision is \n" << precision_type::value << " binary digits.\n";
93 }
94 else
95 {
96 os << "Unknown radix = " << std::numeric_limits<T>::radix << "\n";
97 }
98 }
99 else
100 {
101 os <<
102 "boost::math::policies::precision<" << nameof<T>() << ", Policy> \n"
103 "reports that there is no compile type precision available.\n"
104 "boost::math::tools::digits<" << nameof<T>() << ">() \n"
105 "reports that the current runtime precision is \n" <<
106 boost::math::tools::digits<T>() << " binary digits.\n";
107 }
108
109 typedef typename construction_traits<T, Policy>::type construction_type;
110
111 switch(construction_type::value)
112 {
113 case 0:
114 os <<
115 "No compile time precision is available, the construction method \n"
116 "will be decided at runtime and results will not be cached \n"
117 "- this may lead to poor runtime performance.\n"
118 "Current runtime precision indicates that\n";
119 if(boost::math::tools::digits<T>() > max_string_digits)
120 {
121 os << "the constant will be recalculated on each call.\n";
122 }
123 else
124 {
125 os << "the constant will be constructed from a string on each call.\n";
126 }
127 break;
128 case 1:
129 os <<
130 "The constant will be constructed from a float.\n";
131 break;
132 case 2:
133 os <<
134 "The constant will be constructed from a double.\n";
135 break;
136 case 3:
137 os <<
138 "The constant will be constructed from a long double.\n";
139 break;
140 case 4:
141 os <<
142 "The constant will be constructed from a string (and the result cached).\n";
143 break;
144 default:
145 os <<
146 "The constant will be calculated (and the result cached).\n";
147 break;
148 }
149 os << std::endl;
150 #ifdef BOOST_MSVC
151 #pragma warning(pop)
152 #endif
153 }
154
155 template <class T>
print_info_on_type(std::ostream & os=std::cout BOOST_MATH_APPEND_EXPLICIT_TEMPLATE_TYPE_SPEC (T))156 void print_info_on_type(std::ostream& os = std::cout BOOST_MATH_APPEND_EXPLICIT_TEMPLATE_TYPE_SPEC(T))
157 {
158 print_info_on_type<T, boost::math::policies::policy<> >(os);
159 }
160
161 }}} // namespaces
162
163 #endif // BOOST_MATH_CONSTANTS_INFO_INCLUDED
164