ceph/src/boost/libs/multiprecision/test/issue_13148.cpp

   1 ///////////////////////////////////////////////////////////////////////////////
   2 //  Copyright 2016 John Maddock. Distributed under the Boost
   3 //  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 #include <boost/multiprecision/cpp_int.hpp>
   7 #include <boost/multiprecision/cpp_dec_float.hpp>
   8 #include <boost/multiprecision/cpp_bin_float.hpp>
   9
  10 boost::multiprecision::cpp_rational rationalfromStr(const char* str)
  11 {
  12    boost::multiprecision::cpp_dec_float_50 d1(str);
  13    boost::multiprecision::cpp_rational     result(d1); // <--- eats CPU forever
  14    return result;
  15 }
  16
  17 boost::multiprecision::cpp_rational rationalfromStr2(const char* str)
  18 {
  19    boost::multiprecision::cpp_bin_float_50 d1(str);
  20    boost::multiprecision::cpp_rational     result(d1); // <--- eats CPU forever
  21    return result;
  22 }
  23
  24 int main()
  25 {
  26    // This example is OK.
  27    {
  28       boost::multiprecision::cpp_rational expected = 1;
  29       BOOST_ASSERT(expected == rationalfromStr("1"));
  30    }
  31    // This example is OK.
  32    {
  33       boost::multiprecision::cpp_rational expected = boost::multiprecision::cpp_rational(25) / boost::multiprecision::cpp_rational(10);
  34       BOOST_ASSERT(expected == rationalfromStr("2.5"));
  35    }
  36    // This example is OK.
  37    {
  38       boost::multiprecision::cpp_rational expected = boost::multiprecision::cpp_rational(5) / boost::multiprecision::cpp_rational(1000);
  39       BOOST_ASSERT(expected == rationalfromStr("0.005"));
  40    }
  41    // This example is OK.
  42    {
  43       boost::multiprecision::cpp_rational expected = 0;
  44       BOOST_ASSERT(expected == boost::multiprecision::cpp_rational("0")); // direct cpp_rational from str is OK.
  45    }
  46    // This example fails.
  47    {
  48       boost::multiprecision::cpp_rational expected = 0;
  49       // reachable code
  50       BOOST_ASSERT(expected == rationalfromStr("0")); // cpp_rational from cpp_dec_float_50 is not OK.
  51             // unreachable code
  52    }
  53    {
  54       boost::multiprecision::cpp_rational expected = 0;
  55       // reacheble code
  56       BOOST_ASSERT(expected == rationalfromStr2("0")); // cpp_rational from cpp_dec_float_50 is not OK.
  57           // unreachable code
  58    }
  59    return 0;
  60 }