/////////////////////////////////////////////////////////////////////////////// // Copyright 2016 John Maddock. 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) #include int main() { typedef boost::multiprecision::number > ext_float_t; typedef boost::multiprecision::number > long_ext_float_t; ext_float_t x = 5e15; x += 0.5; ext_float_t x1 = x + 255.0 / (1 << 20); // + 2^-12 - eps ext_float_t x2 = x + 257.0 / (1 << 20); // + 2^-12 + eps double d1 = x1.convert_to(); double d2 = x2.convert_to(); std::cout << std::setprecision(18) << d1 << std::endl; std::cout << std::setprecision(18) << d2 << std::endl; x = 1e7 + 0.5; x1 = x + ldexp(255.0, -38); // + 2^-30 - eps x2 = x + ldexp(257.0, -38); // + 2^-30 + eps float f1 = x1.convert_to(); float f2 = x2.convert_to(); std::cout << std::setprecision(9) << f1 << std::endl; std::cout << std::setprecision(9) << f2 << std::endl; long_ext_float_t lf(1); lf += std::numeric_limits::epsilon(); lf += std::numeric_limits::epsilon() / 2; BOOST_ASSERT(lf != 1); float f3 = lf.convert_to(); std::cout << std::setprecision(9) << f3 << std::endl; return (d1 == d2) && (f1 == f2) && (f3 != 1) ? 0 : 1; }