multiprecision/test/test_cpp_dec_float_round.cpp

68 lines
1.6 KiB
C++

///////////////////////////////////////////////////////////////
// Copyright 2013 Christopher Kormanyos. Distributed under the Boost
// Software License, Version 1.0. (See accompanying file
// LICENSE_1_0.txt or copy at https://www.boost.org/LICENSE_1_0.txt
//
// Test case for ticket:
// #8065: Multiprecision rounding issue
#ifdef _MSC_VER
#define _SCL_SECURE_NO_WARNINGS
#endif
#include <boost/detail/lightweight_test.hpp>
#include "test.hpp"
#include <boost/multiprecision/cpp_dec_float.hpp>
#include <boost/math/special_functions/round.hpp>
template <int N>
static bool round_test_imp()
{
typedef boost::multiprecision::cpp_dec_float<N> mp_backend_type;
typedef boost::multiprecision::number<mp_backend_type, boost::multiprecision::et_off> mp_type;
const mp_type original_digits(1.0F);
const mp_type scale = pow(mp_type(10), N);
mp_type these_digits = original_digits * scale;
these_digits = boost::math::round(these_digits);
these_digits /= scale;
const std::string result = these_digits.str();
return (result == original_digits.str());
}
template <int N>
struct round_test
{
static bool test()
{
return (round_test_imp<N>() && round_test<N - 1>::test());
}
};
template <>
struct round_test<0>
{
static bool test()
{
return round_test_imp<0>();
}
};
int main()
{
//
// Test cpp_dec_float rounding with boost::math::round() at various precisions:
//
const bool round_test_result = round_test<40>::test();
BOOST_CHECK_EQUAL(round_test_result, true);
return boost::report_errors();
}