policy.hpp

来自「Boost provides free peer-reviewed portab」· HPP 代码 · 共 870 行 · 第 1/3 页

//  Copyright John Maddock 2007.
//  Use, modification and distribution are subject to the
//  Boost Software License, Version 1.0. (See accompanying file
//  LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)

#ifndef BOOST_MATH_POLICY_HPP
#define BOOST_MATH_POLICY_HPP

#include <boost/mpl/list.hpp>
#include <boost/mpl/contains.hpp>
#include <boost/mpl/if.hpp>
#include <boost/mpl/find_if.hpp>
#include <boost/mpl/remove_if.hpp>
#include <boost/mpl/vector.hpp>
#include <boost/mpl/push_back.hpp>
#include <boost/mpl/at.hpp>
#include <boost/mpl/size.hpp>
#include <boost/mpl/comparison.hpp>
#include <boost/type_traits/is_same.hpp>
#include <boost/static_assert.hpp>
#include <boost/assert.hpp>
#include <boost/math/tools/config.hpp>
#include <limits>
// Sadly we do need the .h versions of these to be sure of getting
// FLT_MANT_DIG etc.
#include <limits.h>
#include <stdlib.h>
#include <stddef.h>
#include <math.h>

namespace boost{ namespace math{ 

namespace tools{

template <class T>
int digits(BOOST_MATH_EXPLICIT_TEMPLATE_TYPE(T));

}

namespace policies{

//
// Define macros for our default policies, if they're not defined already:
//
#ifndef BOOST_MATH_DOMAIN_ERROR_POLICY
#define BOOST_MATH_DOMAIN_ERROR_POLICY throw_on_error
#endif
#ifndef BOOST_MATH_POLE_ERROR_POLICY
#define BOOST_MATH_POLE_ERROR_POLICY throw_on_error
#endif
#ifndef BOOST_MATH_OVERFLOW_ERROR_POLICY
#define BOOST_MATH_OVERFLOW_ERROR_POLICY throw_on_error
#endif
#ifndef BOOST_MATH_EVALUATION_ERROR_POLICY
#define BOOST_MATH_EVALUATION_ERROR_POLICY throw_on_error
#endif
#ifndef BOOST_MATH_ROUNDING_ERROR_POLICY
#define BOOST_MATH_ROUNDING_ERROR_POLICY throw_on_error
#endif
#ifndef BOOST_MATH_UNDERFLOW_ERROR_POLICY
#define BOOST_MATH_UNDERFLOW_ERROR_POLICY ignore_error
#endif
#ifndef BOOST_MATH_DENORM_ERROR_POLICY
#define BOOST_MATH_DENORM_ERROR_POLICY ignore_error
#endif
#ifndef BOOST_MATH_INDETERMINATE_RESULT_ERROR_POLICY
#define BOOST_MATH_INDETERMINATE_RESULT_ERROR_POLICY ignore_error
#endif
#ifndef BOOST_MATH_DIGITS10_POLICY
#define BOOST_MATH_DIGITS10_POLICY 0
#endif
#ifndef BOOST_MATH_PROMOTE_FLOAT_POLICY
#define BOOST_MATH_PROMOTE_FLOAT_POLICY true
#endif
#ifndef BOOST_MATH_PROMOTE_DOUBLE_POLICY
#ifdef BOOST_MATH_NO_LONG_DOUBLE_MATH_FUNCTIONS
#define BOOST_MATH_PROMOTE_DOUBLE_POLICY false
#else
#define BOOST_MATH_PROMOTE_DOUBLE_POLICY true
#endif
#endif
#ifndef BOOST_MATH_DISCRETE_QUANTILE_POLICY
#define BOOST_MATH_DISCRETE_QUANTILE_POLICY integer_round_outwards
#endif
#ifndef BOOST_MATH_ASSERT_UNDEFINED_POLICY
#define BOOST_MATH_ASSERT_UNDEFINED_POLICY true
#endif
#ifndef BOOST_MATH_MAX_SERIES_ITERATION_POLICY
#define BOOST_MATH_MAX_SERIES_ITERATION_POLICY 1000000
#endif
#ifndef BOOST_MATH_MAX_ROOT_ITERATION_POLICY
#define BOOST_MATH_MAX_ROOT_ITERATION_POLICY 200
#endif

#if !defined(__BORLANDC__)
#define BOOST_MATH_META_INT(type, name, Default)\
   template <type N = Default> struct name : public boost::mpl::int_<N>{};\
   namespace detail{\
   template <type N>\
   char test_is_valid_arg(const name<N>*);\
   char test_is_default_arg(const name<Default>*);\
   template <class T> struct is_##name##_imp\
   {\
      template <type N> static char test(const name<N>*);\
      static double test(...);\
      BOOST_STATIC_CONSTANT(bool, value = sizeof(test(static_cast<T*>(0))) == 1);\
   };\
   }\
   template <class T> struct is_##name : public boost::mpl::bool_<detail::is_##name##_imp<T>::value>{};

#define BOOST_MATH_META_BOOL(name, Default)\
   template <bool N = Default> struct name : public boost::mpl::bool_<N>{};\
   namespace detail{\
   template <bool N>\
   char test_is_valid_arg(const name<N>*);\
   char test_is_default_arg(const name<Default>*);\
   template <class T> struct is_##name##_imp\
   {\
      template <bool N> static char test(const name<N>*);\
      static double test(...);\
      BOOST_STATIC_CONSTANT(bool, value = sizeof(test(static_cast<T*>(0))) == 1);\
   };\
   }\
   template <class T> struct is_##name : public boost::mpl::bool_<detail::is_##name##_imp<T>::value>{};
#else
#define BOOST_MATH_META_INT(Type, name, Default)\
   template <Type N = Default> struct name : public boost::mpl::int_<N>{};\
   namespace detail{\
   template <Type N>\
   char test_is_valid_arg(const name<N>*);\
   char test_is_default_arg(const name<Default>*);\
   template <class T> struct is_##name##_tester\
   {\
      template <Type N> static char test(const name<N>&);\
      static double test(...);\
   };\
   template <class T> struct is_##name##_imp\
   {\
      static T inst;\
      BOOST_STATIC_CONSTANT(bool, value = sizeof(detail::is_##name##_tester<T>::test(inst)) == 1);\
   };\
   }\
   template <class T> struct is_##name : public boost::mpl::bool_<detail::is_##name##_imp<T>::value>\
   {\
      template <class U> struct apply{ typedef is_##name<U> type; };\
   };

#define BOOST_MATH_META_BOOL(name, Default)\
   template <bool N = Default> struct name : public boost::mpl::bool_<N>{};\
   namespace detail{\
   template <bool N>\
   char test_is_valid_arg(const name<N>*);\
   char test_is_default_arg(const name<Default>*);\
   template <class T> struct is_##name##_tester\
   {\
      template <bool N> static char test(const name<N>&);\
      static double test(...);\
   };\
   template <class T> struct is_##name##_imp\
   {\
      static T inst;\
      BOOST_STATIC_CONSTANT(bool, value = sizeof(detail::is_##name##_tester<T>::test(inst)) == 1);\
   };\
   }\
   template <class T> struct is_##name : public boost::mpl::bool_<detail::is_##name##_imp<T>::value>\
   {\
      template <class U> struct apply{ typedef is_##name<U> type;  };\
   };
#endif
//
// Begin by defining policy types for error handling:
//
enum error_policy_type
{
   throw_on_error = 0,
   errno_on_error = 1,
   ignore_error = 2,
   user_error = 3
};

BOOST_MATH_META_INT(error_policy_type, domain_error, BOOST_MATH_DOMAIN_ERROR_POLICY)
BOOST_MATH_META_INT(error_policy_type, pole_error, BOOST_MATH_POLE_ERROR_POLICY)
BOOST_MATH_META_INT(error_policy_type, overflow_error, BOOST_MATH_OVERFLOW_ERROR_POLICY)
BOOST_MATH_META_INT(error_policy_type, underflow_error, BOOST_MATH_UNDERFLOW_ERROR_POLICY)
BOOST_MATH_META_INT(error_policy_type, denorm_error, BOOST_MATH_DENORM_ERROR_POLICY)
BOOST_MATH_META_INT(error_policy_type, evaluation_error, BOOST_MATH_EVALUATION_ERROR_POLICY)
BOOST_MATH_META_INT(error_policy_type, rounding_error, BOOST_MATH_ROUNDING_ERROR_POLICY)
BOOST_MATH_META_INT(error_policy_type, indeterminate_result_error, BOOST_MATH_INDETERMINATE_RESULT_ERROR_POLICY)

//
// Policy types for internal promotion:
//
BOOST_MATH_META_BOOL(promote_float, BOOST_MATH_PROMOTE_FLOAT_POLICY)
BOOST_MATH_META_BOOL(promote_double, BOOST_MATH_PROMOTE_DOUBLE_POLICY)
BOOST_MATH_META_BOOL(assert_undefined, BOOST_MATH_ASSERT_UNDEFINED_POLICY)
//
// Policy types for discrete quantiles:
//
enum discrete_quantile_policy_type
{
   real,
   integer_round_outwards,
   integer_round_inwards,
   integer_round_down,
   integer_round_up,
   integer_round_nearest
};

BOOST_MATH_META_INT(discrete_quantile_policy_type, discrete_quantile, BOOST_MATH_DISCRETE_QUANTILE_POLICY)
//
// Precision:
//
BOOST_MATH_META_INT(int, digits10, BOOST_MATH_DIGITS10_POLICY)
BOOST_MATH_META_INT(int, digits2, 0)
//
// Iterations:
//
BOOST_MATH_META_INT(unsigned long, max_series_iterations, BOOST_MATH_MAX_SERIES_ITERATION_POLICY)
BOOST_MATH_META_INT(unsigned long, max_root_iterations, BOOST_MATH_MAX_ROOT_ITERATION_POLICY)
//
// Define the names for each possible policy:
//
#define BOOST_MATH_PARAMETER(name)\
   BOOST_PARAMETER_TEMPLATE_KEYWORD(name##_name)\
   BOOST_PARAMETER_NAME(name##_name)

struct default_policy{};

namespace detail{
//
// Trait to work out bits precision from digits10 and digits2:
//
template <class Digits10, class Digits2>
struct precision
{
   //
   // Now work out the precision:
   //
   typedef typename mpl::if_c<
      (Digits10::value == 0),
      digits2<0>,
      digits2<((Digits10::value + 1) * 1000L) / 301L>
   >::type digits2_type;
public:
#ifdef __BORLANDC__
   typedef typename mpl::if_c<
      (Digits2::value > ::boost::math::policies::detail::precision<Digits10,Digits2>::digits2_type::value),
      Digits2, digits2_type>::type type;
#else
   typedef typename mpl::if_c<
      (Digits2::value > digits2_type::value),
      Digits2, digits2_type>::type type;
#endif
};

template <class A, class B, bool b>
struct select_result
{
   typedef A type;
};
template <class A, class B>
struct select_result<A, B, false>
{
   typedef typename mpl::deref<B>::type type;
};

template <class Seq, class Pred, class DefaultType>
struct find_arg
{
private:
   typedef typename mpl::find_if<Seq, Pred>::type iter;
   typedef typename mpl::end<Seq>::type end_type;
public:
   typedef typename select_result<
      DefaultType, iter,
      ::boost::is_same<iter, end_type>::value>::type type;
};

double test_is_valid_arg(...);
double test_is_default_arg(...);
char test_is_valid_arg(const default_policy*);
char test_is_default_arg(const default_policy*);

template <class T>
struct is_valid_policy_imp 
{
   BOOST_STATIC_CONSTANT(bool, value = sizeof(test_is_valid_arg(static_cast<T*>(0))) == 1);
};

template <class T>