1 //  (C) Copyright John Maddock 2005.

     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_COMPLEX_DETAILS_INCLUDED

     7 #define BOOST_MATH_COMPLEX_DETAILS_INCLUDED

     8 //

     9 // This header contains all the support code that is common to the

    10 // inverse trig complex functions, it also contains all the includes

    11 // that we need to implement all these functions.

    12 //

    13 #include <boost/detail/workaround.hpp>

    14 #include <boost/config.hpp>

    15 #include <boost/config/no_tr1/complex.hpp>

    16 #include <boost/limits.hpp>

    17 #include <math.h> // isnan where available

    18 #include <cmath>

    19 

    20 #ifdef BOOST_NO_STDC_NAMESPACE

    21 namespace std{ using ::sqrt; }

    22 #endif

    23 

    24 namespace boost{ namespace math{ namespace detail{

    25 

    26 template <class T>

    27 inline bool test_is_nan(T t)

    28 {

    29    // Comparisons with Nan's always fail:

    30    return std::numeric_limits<T>::has_infinity && (!(t <= std::numeric_limits<T>::infinity()) || !(t >= -std::numeric_limits<T>::infinity()));

    31 }

    32 #ifdef isnan

    33 template<> inline bool test_is_nan<float>(float t) { return isnan(t); }

    34 template<> inline bool test_is_nan<double>(double t) { return isnan(t); }

    35 template<> inline bool test_is_nan<long double>(long double t) { return isnan(t); }

    36 #endif

    37 

    38 template <class T>

    39 inline T mult_minus_one(const T& t)

    40 {

    41    return test_is_nan(t) ? t : -t;

    42 }

    43 

    44 template <class T>

    45 inline std::complex<T> mult_i(const std::complex<T>& t)

    46 {

    47    return std::complex<T>(mult_minus_one(t.imag()), t.real());

    48 }

    49 

    50 template <class T>

    51 inline std::complex<T> mult_minus_i(const std::complex<T>& t)

    52 {

    53    return std::complex<T>(t.imag(), mult_minus_one(t.real()));

    54 }

    55 

    56 template <class T>

    57 inline T safe_max(T t)

    58 {

    59    return std::sqrt((std::numeric_limits<T>::max)()) / t;

    60 }

    61 inline long double safe_max(long double t)

    62 {

    63    // long double sqrt often returns infinity due to

    64    // insufficient internal precision:

    65    return std::sqrt((std::numeric_limits<double>::max)()) / t;

    66 }

    67 #if BOOST_WORKAROUND(__BORLANDC__, BOOST_TESTED_AT(0x564))

    68 // workaround for type deduction bug:

    69 inline float safe_max(float t)

    70 {

    71    return std::sqrt((std::numeric_limits<float>::max)()) / t;

    72 }

    73 inline double safe_max(double t)

    74 {

    75    return std::sqrt((std::numeric_limits<double>::max)()) / t;

    76 }

    77 #endif

    78 template <class T>

    79 inline T safe_min(T t)

    80 {

    81    return std::sqrt((std::numeric_limits<T>::min)()) * t;

    82 }

    83 inline long double safe_min(long double t)

    84 {

    85    // long double sqrt often returns zero due to

    86    // insufficient internal precision:

    87    return std::sqrt((std::numeric_limits<double>::min)()) * t;

    88 }

    89 #if BOOST_WORKAROUND(__BORLANDC__, BOOST_TESTED_AT(0x564))

    90 // type deduction workaround:

    91 inline double safe_min(double t)

    92 {

    93    return std::sqrt((std::numeric_limits<double>::min)()) * t;

    94 }

    95 inline float safe_min(float t)

    96 {

    97    return std::sqrt((std::numeric_limits<float>::min)()) * t;

    98 }

    99 #endif

   100 

   101 } } } // namespaces

   102 

   103 #endif // BOOST_MATH_COMPLEX_DETAILS_INCLUDED

   104