id	summary	reporter	owner	description	type	status	milestone	component	version	severity	resolution	keywords	cc
13148	Zero value cannot be converted from cpp_dec_float_50 to cpp_rational	Lev Sch <zorechfan@…>	John Maddock	"String ""boost::multiprecision::cpp_rational result(d1);"" eats CPU forever.

It is reproduced on boost_1_65_0_beta1 and boost_1_64_0.

{{{


boost::multiprecision::cpp_rational rationalfromStr(const char* str)
{
  boost::multiprecision::cpp_dec_float_50 d1(str);
  boost::multiprecision::cpp_rational result(d1); // <--- eats CPU forever
  return result;
}

void test()
{
  // this example is OK
  {
    boost::multiprecision::cpp_rational expected=1;
    assert(expected == rationalfromStr(""1""));
  }
  // this example is OK
  {
    boost::multiprecision::cpp_rational expected=boost::multiprecision::cpp_rational(25)/boost::multiprecision::cpp_rational(10);
    assert(expected == rationalfromStr(""2.5""));
  }
  // this example is OK
  {
    boost::multiprecision::cpp_rational expected=boost::multiprecision::cpp_rational(5)/boost::multiprecision::cpp_rational(1000);
    assert(expected == rationalfromStr(""0.005""));
  }
  // this example is OK
  {
    boost::multiprecision::cpp_rational expected=0;
    assert(expected == boost::multiprecision::cpp_rational(""0"")); // direct cpp_rational from str is ok
  }
  // this example fails
  {
    boost::multiprecision::cpp_rational expected=0;
    // reacheble code
    assert(expected == rationalfromStr(""0"")); // cpp_rational from cpp_dec_float_50 is not ok
    // unreacheble code
  }
}

}}}
"	Bugs	closed	To Be Determined	multiprecision	Boost 1.64.0	Problem	fixed