boost/libs/multiprecision/test/test_rational_io.cpp

// Copyright John Maddock 2011.

// Use, modification and distribution are subject to 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)

#ifdef _MSC_VER
#  define _SCL_SECURE_NO_WARNINGS
#endif

#if !defined(TEST_MPQ) && !defined(TEST_TOMMATH) && !defined(TEST_CPP_INT)
#  define TEST_MPQ
#  define TEST_TOMMATH
#  define TEST_CPP_INT

#ifdef _MSC_VER
#pragma message("CAUTION!!: No backend type specified so testing everything.... this will take some time!!")
#endif
#ifdef __GNUC__
#pragma warning "CAUTION!!: No backend type specified so testing everything.... this will take some time!!"
#endif

#endif

#if defined(TEST_MPQ)
#include <boost/multiprecision/gmp.hpp>
#endif
#if defined(TEST_TOMMATH)
#include <boost/multiprecision/tommath.hpp>
#endif
#ifdef TEST_CPP_INT
#include <boost/multiprecision/cpp_int.hpp>
#endif

#include <boost/algorithm/string/case_conv.hpp>
#include <boost/random/mersenne_twister.hpp>
#include <boost/random/uniform_int.hpp>
#include <boost/multiprecision/rational_adaptor.hpp>
#include "test.hpp"
#include <iostream>
#include <iomanip>

template <class T>
T generate_random()
{
   typedef typename boost::multiprecision::component_type<T>::type int_type;
   static boost::random::uniform_int_distribution<unsigned> ui(0, 20);
   static boost::random::mt19937 gen;
   int_type val = int_type(gen());
   unsigned lim = ui(gen);
   for(unsigned i = 0; i < lim; ++i)
   {
      val *= (gen.max)();
      val += gen();
   }
   int_type denom = int_type(gen());
   lim = ui(gen);
   for(unsigned i = 0; i < lim; ++i)
   {
      denom *= (gen.max)();
      denom += gen();
   }
   return T(val, denom);
}

template <class T>
void do_round_trip(const T& val, std::ios_base::fmtflags f, const boost::mpl::true_&)
{
   std::stringstream ss;
#ifndef BOOST_NO_CXX11_NUMERIC_LIMITS
   ss << std::setprecision(std::numeric_limits<T>::max_digits10);
#else
   ss << std::setprecision(std::numeric_limits<T>::digits10 + 5);
#endif
   ss.flags(f);
   ss << val;
   T new_val = static_cast<T>(ss.str());
   BOOST_CHECK_EQUAL(new_val, val);
   new_val = static_cast<T>(val.str(0, f));
   BOOST_CHECK_EQUAL(new_val, val);
}

template <class T>
void do_round_trip(const T& val, std::ios_base::fmtflags f, const boost::mpl::false_&)
{
   std::stringstream ss;
   ss << std::setprecision(std::numeric_limits<T>::digits10 + 4);
   ss.flags(f);
   ss << val;
   T new_val;
   ss >> new_val;
   BOOST_CHECK_EQUAL(new_val, val);
}

template <class T>
struct is_number : public boost::mpl::false_{};
template <class T>
struct is_number<boost::multiprecision::number<T> > : public boost::mpl::true_{};

template <class T>
void do_round_trip(const T& val, std::ios_base::fmtflags f)
{
   do_round_trip(val, f, is_number<T>());
}

template <class T>
void do_round_trip(const T& val)
{
   do_round_trip(val, std::ios_base::fmtflags(0));
   if(val >= 0)
   {
      do_round_trip(val, std::ios_base::fmtflags(std::ios_base::showbase|std::ios_base::hex));
      do_round_trip(val, std::ios_base::fmtflags(std::ios_base::showbase|std::ios_base::oct));
   }
}

template <class T>
void test_round_trip()
{
   for(unsigned i = 0; i < 1000; ++i)
   {
      T val = generate_random<T>();
      do_round_trip(val);
      do_round_trip(T(-val));
   }
}

int main()
{
#ifdef TEST_MPQ
   test_round_trip<boost::multiprecision::mpq_rational>();
   test_round_trip<boost::rational<boost::multiprecision::mpz_int> >();
   test_round_trip<boost::multiprecision::number<boost::multiprecision::rational_adaptor<boost::multiprecision::gmp_int> > >();
#endif
#ifdef TEST_TOMMATH
   test_round_trip<boost::rational<boost::multiprecision::tom_int> >();
   test_round_trip<boost::multiprecision::tom_rational >();
#endif
#ifdef TEST_CPP_INT
   test_round_trip<boost::rational<boost::multiprecision::cpp_int> >();
   test_round_trip<boost::multiprecision::cpp_rational >();
#endif
   return boost::report_errors();
}