ceph/src/boost/libs/math/example/nonfinite_legacy.cpp

   1 // nonfinite_legacy.cpp
   2
   3 // Distributed under the Boost Software License, Version 1.0.
   4 // (See accompanying file LICENSE_1_0.txt
   5 // or copy at http://www.boost.org/LICENSE_1_0.txt)
   6
   7 // Copyright (c) 2006 Johan Rade
   8 // Copyright (c) 2011 Paul A. Bristow
   9
  10 /*!
  11 \file
  12 \brief Basic tests of nonfinite loopback with output and input facet.
  13
  14 \detail Basic loopback test outputs using the so-called 'legacy' facets,
  15 "1.#INF"  and "1.#QNAN".
  16
  17 and reads back in using nonfinite input 'legacy' facet, and
  18 (if possible) checks if loopback OK.
  19
  20 */
  21
  22 #include <boost/math/special_functions/nonfinite_num_facets.hpp>
  23 using boost::math::nonfinite_num_put;
  24 using boost::math::nonfinite_num_get;
  25
  26 using boost::math::legacy;
  27
  28 #include <iostream>
  29 using std::cout;
  30 using std::endl;
  31
  32 #include <iomanip>
  33 using std::setfill;
  34 using std::setw;
  35
  36 #include <locale>
  37 using std::locale;
  38
  39 #include <sstream>
  40 using std::stringstream;
  41 #include <limits>
  42 using std::numeric_limits;
  43
  44 #include <assert.h>
  45
  46 int main()
  47 {
  48   // Create a new locale with both the nonfinite facets.
  49   std::locale new_locale(std::locale(std::locale(),
  50     new boost::math::nonfinite_num_put<char>),
  51     new boost::math::nonfinite_num_get<char>);
  52
  53   {
  54     stringstream ss;
  55     ss.imbue(new_locale);
  56     double inf = numeric_limits<double>::infinity();
  57     ss << inf; // Write out.
  58     double r;
  59     ss >> r; // Read back in.
  60
  61     cout << "infinity output was " << inf << endl;
  62     cout << "infinity input was " << r << endl;
  63
  64     BOOST_ASSERT(inf == r);
  65   }
  66   {
  67     stringstream ss;
  68     ss.imbue(new_locale);
  69
  70     double nan = numeric_limits<double>::quiet_NaN();
  71     ss << nan; // Write out.
  72     double v;
  73     ss >> v; // Read back in.
  74
  75     cout << "NaN output was " << nan << endl;
  76     cout << "NaN input was " << v << endl;
  77
  78     // BOOST_ASSERT(nan == v); // Always fails because NaN == NaN fails!
  79     // BOOST_ASSERT(nan == numeric_limits<double>::quiet_NaN()); asserts!
  80   }
  81
  82 } // int main()
  83
  84 /*
  85
  86 Output:
  87
  88 infinity output was 1.#INF
  89 infinity input was 1.#INF
  90 NaN output was 1.#QNAN
  91 NaN input was 1.#QNAN
  92
  93 */
  94