| /** nonfinite_num_facet.cpp |
| * |
| * Copyright (c) 2011 Francois Mauger |
| * Copyright (c) 2011 Paul A. Bristow |
| * |
| * Distributed under 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) |
| * |
| * This simple program illustrates how to use the |
| * `boost/math/nonfinite_num_facets.hpp' material from the original |
| * Floating Point Utilities contribution by Johan Rade. |
| * Floating Point Utility library has been accepted into Boost, |
| * but the utilities have been/will be incorporated into Boost.Math library. |
| * |
| \file |
| |
| \brief A fairly simple example of using non_finite_num facet for |
| C99 standard output of infinity and NaN. |
| |
| \detail This program illustrates how to use the |
| `boost/math/nonfinite_num_facets.hpp' material from the original |
| Floating Point Utilities contribution by Johan Rade. |
| Floating Point Utility library has been accepted into Boost, |
| but the utilities have been/will be incorporated into Boost.Math library. |
| |
| Based on an example from Francois Mauger. |
| |
| Double and float variables are assigned ordinary finite values (pi), |
| and nonfinite like infinity and NaN. |
| |
| These values are then output and read back in, and then redisplayed. |
| |
| */ |
| |
| #ifdef _MSC_VER |
| # pragma warning(disable : 4127) // conditional expression is constant. |
| #endif |
| |
| #include <iostream> |
| #include <iomanip> |
| using std::cout; |
| using std::endl; |
| |
| #include <limits> // numeric_limits |
| using std::numeric_limits; |
| |
| #include <boost/cstdint.hpp> |
| |
| #include <boost/math/special_functions/nonfinite_num_facets.hpp> |
| |
| static const char sep = ','; // Separator of bracketed float and double values. |
| |
| // Use max_digits10 (or equivalent) to obtain |
| // all potentially significant decimal digits for the floating-point types. |
| |
| #ifdef BOOST_NO_NUMERIC_LIMITS_LOWEST |
| std::streamsize max_digits10_float = 2 + std::numeric_limits<float>::digits * 30103UL / 100000UL; |
| std::streamsize max_digits10_double = 2 + std::numeric_limits<double>::digits * 30103UL / 100000UL; |
| #else |
| // Can use new C++0X max_digits10 (the maximum potentially significant digits). |
| std::streamsize max_digits10_float = std::numeric_limits<float>::max_digits10; |
| std::streamsize max_digits10_double = std::numeric_limits<double>::max_digits10; |
| #endif |
| |
| |
| /* A class with a float and a double */ |
| struct foo |
| { |
| foo () : fvalue (3.1415927F), dvalue (3.1415926535897931) |
| { |
| } |
| // Set both the values to -infinity : |
| void minus_infinity () |
| { |
| fvalue = -std::numeric_limits<float>::infinity (); |
| dvalue = -std::numeric_limits<double>::infinity (); |
| return; |
| } |
| // Set the values to +infinity : |
| void plus_infinity () |
| { |
| fvalue = +std::numeric_limits<float>::infinity (); |
| dvalue = +std::numeric_limits<double>::infinity (); |
| return; |
| } |
| // Set the values to NaN : |
| void nan () |
| { |
| fvalue = +std::numeric_limits<float>::quiet_NaN (); |
| dvalue = +std::numeric_limits<double>::quiet_NaN (); |
| return; |
| } |
| // Print a foo: |
| void print (std::ostream & a_out, const std::string & a_title) |
| { |
| if (a_title.empty ()) a_out << "foo"; |
| else a_out << a_title; |
| a_out << " : " << std::endl; |
| a_out << "|-- " << "fvalue = "; |
| |
| a_out.precision (max_digits10_float); |
| a_out << fvalue << std::endl; |
| a_out << "`-- " << "dvalue = "; |
| a_out.precision (max_digits10_double); |
| a_out << dvalue << std::endl; |
| return; |
| } |
| |
| // I/O operators for a foo structure of a float and a double : |
| friend std::ostream & operator<< (std::ostream & a_out, const foo & a_foo); |
| friend std::istream & operator>> (std::istream & a_in, foo & a_foo); |
| |
| // Attributes : |
| float fvalue; // Single precision floating number. |
| double dvalue; // Double precision floating number. |
| }; |
| |
| std::ostream & operator<< (std::ostream & a_out, const foo & a_foo) |
| { // Output bracketed FPs, for example "(3.1415927,3.1415926535897931)" |
| a_out.precision (max_digits10_float); |
| a_out << "(" << a_foo.fvalue << sep ; |
| a_out.precision (max_digits10_double); |
| a_out << a_foo.dvalue << ")"; |
| return a_out; |
| } |
| |
| std::istream & operator>> (std::istream & a_in, foo & a_foo) |
| { // Input bracketed floating-point values into a foo structure, |
| // for example from "(3.1415927,3.1415926535897931)" |
| char c = 0; |
| a_in.get (c); |
| if (c != '(') |
| { |
| std::cerr << "ERROR: operator>> No ( " << std::endl; |
| a_in.setstate(std::ios::failbit); |
| return a_in; |
| } |
| float f; |
| a_in >> std::ws >> f; |
| if (! a_in) |
| { |
| return a_in; |
| } |
| a_in >> std::ws; |
| a_in.get (c); |
| if (c != sep) |
| { |
| std::cerr << "ERROR: operator>> c='" << c << "'" << std::endl; |
| std::cerr << "ERROR: operator>> No '" << sep << "'" << std::endl; |
| a_in.setstate(std::ios::failbit); |
| return a_in; |
| } |
| double d; |
| a_in >> std::ws >> d; |
| if (! a_in) |
| { |
| return a_in; |
| } |
| a_in >> std::ws; |
| a_in.get (c); |
| if (c != ')') |
| { |
| std::cerr << "ERROR: operator>> No ) " << std::endl; |
| a_in.setstate(std::ios::failbit); |
| return a_in; |
| } |
| a_foo.fvalue = f; |
| a_foo.dvalue = d; |
| return a_in; |
| } // std::istream & operator>> (std::istream & a_in, foo & a_foo) |
| |
| int main () |
| { |
| std::cout << "nonfinite_num_facet simple example." << std::endl; |
| |
| if((std::numeric_limits<double>::has_infinity == false) || (std::numeric_limits<double>::infinity() == 0)) |
| { |
| std::cout << "Infinity not supported on this platform." << std::endl; |
| return 0; |
| } |
| |
| if((std::numeric_limits<double>::has_quiet_NaN == false) || (std::numeric_limits<double>::quiet_NaN() == 0)) |
| { |
| std::cout << "NaN not supported on this platform." << std::endl; |
| return 0; |
| } |
| |
| #ifdef BOOST_NO_NUMERIC_LIMITS_LOWEST |
| cout << "BOOST_NO_NUMERIC_LIMITS_LOWEST is defined, so no max_digits10 available either:" |
| "\n we'll have to calculate our own version." << endl; |
| #endif |
| std::cout << "std::numeric_limits<float>::max_digits10 is " << max_digits10_float << endl; |
| std::cout << "std::numeric_limits<double>::max_digits10 is " << max_digits10_double << endl; |
| |
| std::locale the_default_locale (std::locale::classic ()); |
| |
| { |
| std::cout << "Write to a string buffer (using default locale) :" << std::endl; |
| foo f0; // pi |
| foo f1; f1.minus_infinity (); |
| foo f2; f2.plus_infinity (); |
| foo f3; f3.nan (); |
| |
| f0.print (std::cout, "f0"); // pi |
| f1.print (std::cout, "f1"); // +inf |
| f2.print (std::cout, "f2"); // -inf |
| f3.print (std::cout, "f3"); // NaN |
| |
| std::ostringstream oss; |
| std::locale C99_out_locale (the_default_locale, new boost::math::nonfinite_num_put<char>); |
| oss.imbue (C99_out_locale); |
| oss.precision (15); |
| oss << f0 << f1 << f2 << f3; |
| std::cout << "Output in C99 format is: \"" << oss.str () << "\"" << std::endl; |
| std::cout << "Output done." << std::endl; |
| } |
| |
| { |
| std::string the_string = "(3.1415927,3.1415926535897931)(-inf,-inf)(inf,inf)(nan,nan)"; // C99 format |
| // Must have correct separator! |
| std::cout << "Read C99 format from a string buffer containing \"" << the_string << "\""<< std::endl; |
| |
| std::locale C99_in_locale (the_default_locale, new boost::math::nonfinite_num_get<char>); |
| std::istringstream iss (the_string); |
| iss.imbue (C99_in_locale); |
| |
| foo f0, f1, f2, f3; |
| iss >> f0 >> f1 >> f2 >> f3; |
| if (! iss) |
| { |
| std::cerr << "Input Format error !" << std::endl; |
| } |
| else |
| { |
| std::cerr << "Input OK." << std::endl; |
| cout << "Display in default locale format " << endl; |
| f0.print (std::cout, "f0"); |
| f1.print (std::cout, "f1"); |
| f2.print (std::cout, "f2"); |
| f3.print (std::cout, "f3"); |
| } |
| std::cout << "Input done." << std::endl; |
| } |
| |
| std::cout << "End nonfinite_num_facet.cpp" << std::endl; |
| return 0; |
| } // int main() |
| |
| // end of test_nonfinite_num_facets.cpp |
| |
| /* |
| |
| Output: |
| |
| nonfinite_num_facet simple example. |
| std::numeric_limits<float>::max_digits10 is 8 |
| std::numeric_limits<double>::max_digits10 is 17 |
| Write to a string buffer (using default locale) : |
| f0 : |
| |-- fvalue = 3.1415927 |
| `-- dvalue = 3.1415926535897931 |
| f1 : |
| |-- fvalue = -1.#INF |
| `-- dvalue = -1.#INF |
| f2 : |
| |-- fvalue = 1.#INF |
| `-- dvalue = 1.#INF |
| f3 : |
| |-- fvalue = 1.#QNAN |
| `-- dvalue = 1.#QNAN |
| Output in C99 format is: "(3.1415927,3.1415926535897931)(-inf,-inf)(inf,inf)(nan,nan)" |
| Output done. |
| Read C99 format from a string buffer containing "(3.1415927,3.1415926535897931)(-inf,-inf)(inf,inf)(nan,nan)" |
| Display in default locale format |
| f0 : |
| |-- fvalue = 3.1415927 |
| `-- dvalue = 3.1415926535897931 |
| f1 : |
| |-- fvalue = -1.#INF |
| `-- dvalue = -1.#INF |
| f2 : |
| |-- fvalue = 1.#INF |
| `-- dvalue = 1.#INF |
| f3 : |
| |-- fvalue = 1.#QNAN |
| `-- dvalue = 1.#QNAN |
| Input done. |
| End nonfinite_num_facet.cpp |
| |
| */ |