Chris@16: //  Copyright John Maddock 2010.
Chris@16: //  Use, modification and distribution are subject to the
Chris@16: //  Boost Software License, Version 1.0. (See accompanying file
Chris@16: //  LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
Chris@16: 
Chris@16: #ifdef _MSC_VER
Chris@16: #  pragma once
Chris@16: #endif
Chris@16: 
Chris@16: #ifndef BOOST_MATH_CONSTANTS_INFO_INCLUDED
Chris@16: #define BOOST_MATH_CONSTANTS_INFO_INCLUDED
Chris@16: 
Chris@16: #include <boost/math/constants/constants.hpp>
Chris@16: #include <iostream>
Chris@16: #include <iomanip>
Chris@16: #include <typeinfo>
Chris@16: 
Chris@16: namespace boost{ namespace math{ namespace constants{
Chris@16: 
Chris@16:    namespace detail{
Chris@16: 
Chris@16:       template <class T>
Chris@16:       const char* nameof(BOOST_MATH_EXPLICIT_TEMPLATE_TYPE_SPEC(T))
Chris@16:       {
Chris@16:          return typeid(T).name();
Chris@16:       }
Chris@16:       template <>
Chris@16:       const char* nameof<float>(BOOST_MATH_EXPLICIT_TEMPLATE_TYPE_SPEC(float))
Chris@16:       {
Chris@16:          return "float";
Chris@16:       }
Chris@16:       template <>
Chris@16:       const char* nameof<double>(BOOST_MATH_EXPLICIT_TEMPLATE_TYPE_SPEC(double))
Chris@16:       {
Chris@16:          return "double";
Chris@16:       }
Chris@16:       template <>
Chris@16:       const char* nameof<long double>(BOOST_MATH_EXPLICIT_TEMPLATE_TYPE_SPEC(long double))
Chris@16:       {
Chris@16:          return "long double";
Chris@16:       }
Chris@16: 
Chris@16:    }
Chris@16: 
Chris@16: template <class T, class Policy>
Chris@16: 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))
Chris@16: {
Chris@16:    using detail::nameof;
Chris@16: #ifdef BOOST_MSVC
Chris@16: #pragma warning(push)
Chris@16: #pragma warning(disable:4127)
Chris@16: #endif
Chris@16:    os <<
Chris@16:       "Information on the Implementation and Handling of \n"
Chris@16:       "Mathematical Constants for Type " << nameof<T>() <<
Chris@16:       "\n\n"
Chris@16:       "Checking for std::numeric_limits<" << nameof<T>() << "> specialisation: " <<
Chris@16:       (std::numeric_limits<T>::is_specialized ? "yes" : "no") << std::endl;
Chris@16:    if(std::numeric_limits<T>::is_specialized)
Chris@16:    {
Chris@16:       os <<
Chris@16:          "std::numeric_limits<" << nameof<T>() << ">::digits reports that the radix is " << std::numeric_limits<T>::radix << ".\n";
Chris@16:       if (std::numeric_limits<T>::radix == 2)
Chris@16:       {
Chris@16:       os <<
Chris@16:          "std::numeric_limits<" << nameof<T>() << ">::digits reports that the precision is \n" << std::numeric_limits<T>::digits << " binary digits.\n";
Chris@16:       }
Chris@16:       else if (std::numeric_limits<T>::radix == 10)
Chris@16:       {
Chris@16:          os <<
Chris@16:          "std::numeric_limits<" << nameof<T>() << ">::digits reports that the precision is \n" << std::numeric_limits<T>::digits10 << " decimal digits.\n";
Chris@16:          os <<
Chris@16:          "std::numeric_limits<" << nameof<T>() << ">::digits reports that the precision is \n"
Chris@16:          << std::numeric_limits<T>::digits * 1000L /301L << " binary digits.\n";  // divide by log2(10) - about 3 bits per decimal digit.
Chris@16:       }
Chris@16:       else
Chris@16:       {
Chris@16:         os << "Unknown radix = " << std::numeric_limits<T>::radix << "\n";
Chris@16:       }
Chris@16:    }
Chris@16:    typedef typename boost::math::policies::precision<T, Policy>::type precision_type;
Chris@16:    if(precision_type::value)
Chris@16:    {
Chris@16:       if (std::numeric_limits<T>::radix == 2)
Chris@16:       {
Chris@16:        os <<
Chris@16:        "boost::math::policies::precision<" << nameof<T>() << ", " << nameof<Policy>() << " reports that the compile time precision is \n" << precision_type::value << " binary digits.\n";
Chris@16:       }
Chris@16:       else if (std::numeric_limits<T>::radix == 10)
Chris@16:       {
Chris@16:          os <<
Chris@16:          "boost::math::policies::precision<" << nameof<T>() << ", " << nameof<Policy>() << " reports that the compile time precision is \n" << precision_type::value << " binary digits.\n";
Chris@16:       }
Chris@16:       else
Chris@16:       {
Chris@16:         os << "Unknown radix = " << std::numeric_limits<T>::radix <<  "\n";
Chris@16:       }
Chris@16:    }
Chris@16:    else
Chris@16:    {
Chris@16:       os <<
Chris@16:          "boost::math::policies::precision<" << nameof<T>() << ", Policy> \n"
Chris@16:          "reports that there is no compile type precision available.\n"
Chris@16:          "boost::math::tools::digits<" << nameof<T>() << ">() \n"
Chris@16:          "reports that the current runtime precision is \n" <<
Chris@16:          boost::math::tools::digits<T>() << " binary digits.\n";
Chris@16:    }
Chris@16: 
Chris@16:    typedef typename construction_traits<T, Policy>::type construction_type;
Chris@16: 
Chris@16:    switch(construction_type::value)
Chris@16:    {
Chris@16:    case 0:
Chris@16:       os <<
Chris@16:          "No compile time precision is available, the construction method \n"
Chris@16:          "will be decided at runtime and results will not be cached \n"
Chris@16:          "- this may lead to poor runtime performance.\n"
Chris@16:          "Current runtime precision indicates that\n";
Chris@16:       if(boost::math::tools::digits<T>() > max_string_digits)
Chris@16:       {
Chris@16:          os << "the constant will be recalculated on each call.\n";
Chris@16:       }
Chris@16:       else
Chris@16:       {
Chris@16:          os << "the constant will be constructed from a string on each call.\n";
Chris@16:       }
Chris@16:       break;
Chris@16:    case 1:
Chris@16:       os <<
Chris@16:          "The constant will be constructed from a float.\n";
Chris@16:       break;
Chris@16:    case 2:
Chris@16:       os <<
Chris@16:          "The constant will be constructed from a double.\n";
Chris@16:       break;
Chris@16:    case 3:
Chris@16:       os <<
Chris@16:          "The constant will be constructed from a long double.\n";
Chris@16:       break;
Chris@16:    case 4:
Chris@16:       os <<
Chris@16:          "The constant will be constructed from a string (and the result cached).\n";
Chris@16:       break;
Chris@16:    default:
Chris@16:       os <<
Chris@16:          "The constant will be calculated (and the result cached).\n";
Chris@16:       break;
Chris@16:    }
Chris@16:    os << std::endl;
Chris@16: #ifdef BOOST_MSVC
Chris@16: #pragma warning(pop)
Chris@16: #endif
Chris@16: }
Chris@16: 
Chris@16: template <class T>
Chris@16: void print_info_on_type(std::ostream& os = std::cout BOOST_MATH_APPEND_EXPLICIT_TEMPLATE_TYPE_SPEC(T))
Chris@16: {
Chris@16:    print_info_on_type<T, boost::math::policies::policy<> >(os);
Chris@16: }
Chris@16: 
Chris@16: }}} // namespaces
Chris@16: 
Chris@16: #endif // BOOST_MATH_CONSTANTS_INFO_INCLUDED