123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160161162163164165166167168169170171172173174175176177178179180181182183184185186187188189190191192193194195196197198199200201202203204205206207208209210211212213214215216217218219220221222223224225226227228229230231232233234235236237238239240241242243244245246247248249250251252253254255256257258259260261262263264265266267268269270271272273274275276277278279280281282283284285286287288289290291 |
- /** 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_CXX11_NUMERIC_LIMITS
- 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_CXX11_NUMERIC_LIMITS
- cout << "BOOST_NO_CXX11_NUMERIC_LIMITS 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
- */
|