/Libraries/Boost1.40/libs/config/test/math_info.cpp

//  (C) Copyright John Maddock 2005. 

//  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)



//  See http://www.boost.org/libs/config/test for most recent version.



//

// This test prints out informative information about <math.h>, <float.h>

// and <limits>.  Note that this file does require a correctly configured

// Boost setup, and so can't be folded into config_info which is designed

// to function without Boost.Confg support.  Each test is documented in

// more detail below.

//



#include <boost/limits.hpp>

#include <limits.h>

#include <math.h>

#include <cmath>

#include <float.h>

#include <iostream>

#include <iomanip>

#include <cstring>

#include <boost/type_traits/alignment_of.hpp>



#ifdef BOOST_NO_STDC_NAMESPACE

namespace std{ using ::strcmp; using ::pow; using ::fabs; using ::sqrt; using ::sin; using ::atan2; }

#endif



static unsigned int indent = 4;

static unsigned int width = 40;



void print_macro(const char* name, const char* value)

{

   // if name == value+1 then then macro is not defined,

   // in which case we don't print anything:

   if(0 != std::strcmp(name, value+1))

   {

      for(unsigned i = 0; i < indent; ++i) std::cout.put(' ');

      std::cout << std::setw(width);

      std::cout.setf(std::istream::left, std::istream::adjustfield);

      std::cout << name;

      if(value[1])

      {

         // macro has a value:

         std::cout << value << "\n";

      }

      else

      {

         // macro is defined but has no value:

         std::cout << " [no value]\n";

      }

   }

}



#define PRINT_MACRO(X) print_macro(#X, BOOST_STRINGIZE(=X))



template <class T>

void print_expression(const char* expression, T val)

{

   for(unsigned i = 0; i < indent; ++i) std::cout.put(' ');

   std::cout << std::setw(width);

   std::cout.setf(std::istream::left, std::istream::adjustfield);

   std::cout << std::setprecision(std::numeric_limits<T>::digits10+2);

   std::cout << expression << "=" << val << std::endl;

}



#define PRINT_EXPRESSION(E) print_expression(#E, E);





template <class T>

void print_limits(T, const char* name)

{

   //

   // Output general information on numeric_limits, as well as 

   // probing known and supected problems.

   //

   std::cout << 

      "~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~\n"

      "std::numeric_limits information for type " << name << std::endl;

   std::cout << 

      "    is_specialized       = " << std::numeric_limits<T>::is_specialized << std::endl;

   std::cout << 

      "    min" "()                = " << std::setprecision(std::numeric_limits<T>::digits10 + 2) << (std::numeric_limits<T>::min)() << std::endl;

   std::cout << 

      "    max" "()                = " << std::setprecision(std::numeric_limits<T>::digits10 + 2) << (std::numeric_limits<T>::max)() << std::endl;

   std::cout << 

      "    digits               = " << std::numeric_limits<T>::digits << std::endl;

   std::cout << 

      "    digits10             = " << std::numeric_limits<T>::digits10 << std::endl;

   std::cout << 

      "    is_signed            = " << std::numeric_limits<T>::is_signed << std::endl;

   std::cout << 

      "    is_integer           = " << std::numeric_limits<T>::is_integer << std::endl;

   std::cout << 

      "    is_exact             = " << std::numeric_limits<T>::is_exact << std::endl;

   std::cout << 

      "    radix                = " << std::numeric_limits<T>::radix << std::endl;



   std::cout << 

      "    epsilon()            = " << std::setprecision(std::numeric_limits<T>::digits10 + 2) << (std::numeric_limits<T>::epsilon)() << std::endl;

   std::cout << 

      "    round_error()        = " << std::setprecision(std::numeric_limits<T>::digits10 + 2) << (std::numeric_limits<T>::round_error)() << std::endl;



   std::cout << 

      "    min_exponent         = " << std::numeric_limits<T>::min_exponent << std::endl;

   std::cout << 

      "    min_exponent10       = " << std::numeric_limits<T>::min_exponent10 << std::endl;

   std::cout << 

      "    max_exponent         = " << std::numeric_limits<T>::max_exponent << std::endl;

   std::cout << 

      "    max_exponent10       = " << std::numeric_limits<T>::max_exponent10 << std::endl;

   std::cout << 

      "    has_infinity         = " << std::numeric_limits<T>::has_infinity << std::endl;

   std::cout << 

      "    has_quiet_NaN        = " << std::numeric_limits<T>::has_quiet_NaN << std::endl;

   std::cout << 

      "    has_signaling_NaN    = " << std::numeric_limits<T>::has_signaling_NaN << std::endl;

   std::cout << 

      "    has_denorm           = " << std::numeric_limits<T>::has_denorm << std::endl;

   std::cout << 

      "    has_denorm_loss      = " << std::numeric_limits<T>::has_denorm_loss << std::endl;



   std::cout << 

      "    infinity()           = " << std::setprecision(std::numeric_limits<T>::digits10 + 2) << (std::numeric_limits<T>::infinity)() << std::endl;

   std::cout << 

      "    quiet_NaN()          = " << std::setprecision(std::numeric_limits<T>::digits10 + 2) << (std::numeric_limits<T>::quiet_NaN)() << std::endl;

   std::cout << 

      "    signaling_NaN()      = " << std::setprecision(std::numeric_limits<T>::digits10 + 2) << (std::numeric_limits<T>::signaling_NaN)() << std::endl;

   std::cout << 

      "    denorm_min()         = " << std::setprecision(std::numeric_limits<T>::digits10 + 2) << (std::numeric_limits<T>::denorm_min)() << std::endl;

   



   std::cout << 

      "    is_iec559            = " << std::numeric_limits<T>::is_iec559 << std::endl;

   std::cout << 

      "    is_bounded           = " << std::numeric_limits<T>::is_bounded << std::endl;

   std::cout << 

      "    is_modulo            = " << std::numeric_limits<T>::is_modulo << std::endl;

   std::cout << 

      "    traps                = " << std::numeric_limits<T>::traps << std::endl;

   std::cout << 

      "    tinyness_before      = " << std::numeric_limits<T>::tinyness_before << std::endl;

   std::cout << 

      "    round_style          = " << std::numeric_limits<T>::round_style << std::endl << std::endl;



   if(std::numeric_limits<T>::is_exact == 0)

   {

      bool r = std::numeric_limits<T>::epsilon() == std::pow(static_cast<T>(std::numeric_limits<T>::radix), 1-std::numeric_limits<T>::digits);

      if(r)

         std::cout << "Epsilon has sane value of std::pow(std::numeric_limits<T>::radix, 1-std::numeric_limits<T>::digits)." << std::endl;

      else

         std::cout << "CAUTION: epsilon does not have a sane value." << std::endl;

      std::cout << std::endl;

   }

   std::cout << 

      "    sizeof(" << name << ") = " << sizeof(T) << std::endl;

   std::cout << 

      "    alignment_of<" << name << "> = " << boost::alignment_of<T>::value << std::endl << std::endl;

}

/*

template <class T>

bool is_same_type(T, T)

{

   return true;

}*/

bool is_same_type(float, float)

{ return true; }

bool is_same_type(double, double)

{ return true; }

bool is_same_type(long double, long double)

{ return true; }

template <class T, class U>

bool is_same_type(T, U)

{

   return false;

}



//

// We need this to test whether abs has been overloaded for

// the floating point types or not:

//

namespace std{

#if !BOOST_WORKAROUND(BOOST_MSVC, == 1300)

template <class T>

char abs(T)

{

   return ' ';

}

#endif

}





template <class T>

void test_overloads(T, const char* name)

{

   //

   // Probe known and suspected problems with the std lib Math functions.

   //

   std::cout << 

      "~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~\n"

      "Math function overload information for type " << name << std::endl;



   //

   // Are the math functions overloaded for type T,

   // or do we just get double versions?

   //

   bool r = is_same_type(std::fabs(T(0)), T(0));

   r &= is_same_type(std::sqrt(T(0)), T(0));

   r &= is_same_type(std::sin(T(0)), T(0));

   if(r)

      std::cout << "The Math functions are overloaded for type " << name << std::endl;

   else

      std::cout << "CAUTION: The Math functions are NOT overloaded for type " << name << std::endl;



   //

   // Check that a few of the functions work OK, we do this because if these

   // are implemented as double precision internally then we can get

   // overflow or underflow when passing arguments of other types.

   //

   r = (std::fabs((std::numeric_limits<T>::max)()) == (std::numeric_limits<T>::max)());

   r &= (std::fabs(-(std::numeric_limits<T>::max)()) == (std::numeric_limits<T>::max)());

   r &= (std::fabs((std::numeric_limits<T>::min)()) == (std::numeric_limits<T>::min)());

   r &= (std::fabs(-(std::numeric_limits<T>::min)()) == (std::numeric_limits<T>::min)());

   if(r)

      std::cout << "std::fabs looks OK for type " << name << std::endl;

   else

      std::cout << "CAUTION: std::fabs is broken for type " << name << std::endl;



   //

   // abs not overloaded for real arguments with VC6 (and others?)

   //

   r = (std::abs((std::numeric_limits<T>::max)()) == (std::numeric_limits<T>::max)());

   r &= (std::abs(-(std::numeric_limits<T>::max)()) == (std::numeric_limits<T>::max)());

   r &= (std::abs((std::numeric_limits<T>::min)()) == (std::numeric_limits<T>::min)());

   r &= (std::abs(-(std::numeric_limits<T>::min)()) == (std::numeric_limits<T>::min)());

   if(r)

      std::cout << "std::abs looks OK for type " << name << std::endl;

   else

      std::cout << "CAUTION: std::abs is broken for type " << name << std::endl;



   //

   // std::sqrt on FreeBSD converts long double arguments to double leading to

   // overflow/underflow:

   //

   r = (std::sqrt((std::numeric_limits<T>::max)()) < (std::numeric_limits<T>::max)());

   if(r)

      std::cout << "std::sqrt looks OK for type " << name << std::endl;

   else

      std::cout << "CAUTION: std::sqrt is broken for type " << name << std::endl;



   //

   // Sanity check for atan2: verify that it returns arguments in the correct

   // range and not just atan(x/y).

   //

   static const T half_pi = static_cast<T>(1.57079632679489661923132169163975144L);



   T val = std::atan2(T(-1), T(-1));

   r = -half_pi > val;

   val = std::atan2(T(1), T(-1));

   r &= half_pi < val;

   val = std::atan2(T(1), T(1));

   r &= (val > 0) && (val < half_pi);

   val = std::atan2(T(-1), T(1));

   r &= (val < 0) && (val > -half_pi);

   if(r)

      std::cout << "std::atan2 looks OK for type " << name << std::endl;

   else

      std::cout << "CAUTION: std::atan2 is broken for type " << name << std::endl;

}







int main()

{

   //

   // Start by printing the values of the macros from float.h

   //

   std::cout << 

      "~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~\n"

      "Macros from <math.h>" << std::endl;



#ifdef __BORLANDC__

   // Turn off hardware exceptions so we don't just abort 

   // when calling numeric_limits members.

   _control87(MCW_EM,MCW_EM);

#endif



   PRINT_EXPRESSION(HUGE_VAL);

#ifdef HUGE_VALF

   PRINT_EXPRESSION(HUGE_VALF);

#endif

#ifdef HUGE_VALL

   PRINT_EXPRESSION(HUGE_VALL);

#endif

#ifdef INFINITY

   PRINT_EXPRESSION(INFINITY);

#endif



   PRINT_MACRO(NAN);

   PRINT_MACRO(FP_INFINITE);

   PRINT_MACRO(FP_NAN);

   PRINT_MACRO(FP_NORMAL);

   PRINT_MACRO(FP_SUBNORMAL);

   PRINT_MACRO(FP_ZERO);

   PRINT_MACRO(FP_FAST_FMA);

   PRINT_MACRO(FP_FAST_FMAF);

   PRINT_MACRO(FP_FAST_FMAL);

   PRINT_MACRO(FP_ILOGB0);

   PRINT_MACRO(FP_ILOGBNAN);

   PRINT_MACRO(MATH_ERRNO);

   PRINT_MACRO(MATH_ERREXCEPT);



   PRINT_EXPRESSION(FLT_MIN_10_EXP);

   PRINT_EXPRESSION(FLT_DIG);

   PRINT_EXPRESSION(FLT_MIN_EXP);

   PRINT_EXPRESSION(FLT_EPSILON);

   PRINT_EXPRESSION(FLT_RADIX);

   PRINT_EXPRESSION(FLT_MANT_DIG);

   PRINT_EXPRESSION(FLT_ROUNDS);

   PRINT_EXPRESSION(FLT_MAX);

   PRINT_EXPRESSION(FLT_MAX_10_EXP);

   PRINT_EXPRESSION(FLT_MAX_EXP);

   PRINT_EXPRESSION(FLT_MIN);

   PRINT_EXPRESSION(DBL_DIG);

   PRINT_EXPRESSION(DBL_MIN_EXP);

   PRINT_EXPRESSION(DBL_EPSILON);

   PRINT_EXPRESSION(DBL_MANT_DIG);

   PRINT_EXPRESSION(DBL_MAX);

   PRINT_EXPRESSION(DBL_MIN);

   PRINT_EXPRESSION(DBL_MAX_10_EXP);

   PRINT_EXPRESSION(DBL_MAX_EXP);

   PRINT_EXPRESSION(DBL_MIN_10_EXP);

   PRINT_EXPRESSION(LDBL_MAX_10_EXP);

   PRINT_EXPRESSION(LDBL_MAX_EXP);

   PRINT_EXPRESSION(LDBL_MIN);

   PRINT_EXPRESSION(LDBL_MIN_10_EXP);

   PRINT_EXPRESSION(LDBL_DIG);

   PRINT_EXPRESSION(LDBL_MIN_EXP);

   PRINT_EXPRESSION(LDBL_EPSILON);

   PRINT_EXPRESSION(LDBL_MANT_DIG);

   PRINT_EXPRESSION(LDBL_MAX);



   std::cout << std::endl;



   //

   // print out numeric_limits info:

   //

   print_limits(float(0), "float");

   print_limits(double(0), "double");

   print_limits((long double)(0), "long double");



   //

   // print out function overload information:

   //

   test_overloads(float(0), "float");

   test_overloads(double(0), "double");

   test_overloads((long double)(0), "long double");

   return 0;

}