boost::spirit::double_ fails with large numbers

[Tobias Reh <treh@…>]

Since 1.59.0, spirit fails to parse large doubles when they are written out.

#include <boost/spirit/include/qi_real.hpp>
#include <iostream>

int main()
{
  // 2^100, exactly representable as double
  auto str = "1267650600228229401496703205376"; 

  double f;

  boost::spirit::qi::parse(str, str + strlen(str), boost::spirit::double_, f);

  // The following code line prints
  //  1.26765e+30 (with boost 1.58.0, correct)
  // -9.25596e+61 (with boost 1.59.0)
  std::cout << f << std::endl;

  return 0;
}

[Tobias Reh <treh@…>]

Actually the line

boost::spirit::qi::parse(str, str + strlen(str), boost::spirit::double_, f);

returns false with boost 1.59.0. So it does not "yield a wrong result" but fails, and I have updated the summary accordingly.

It is still a regression.

[Joel de Guzman]

I'll have a look over the weekend. Thanks for the report.

[Joel de Guzman]

Fixed in ​https://github.com/boostorg/spirit/commit/be7640bd692684b2fd7532745ddd6343e551744d tests added