Ticket #6126: test_signed_integer_output_with_karma_minimal.cpp

/*
 * test_signed_integer_output_with_karma_minimal -- Minimal test case
 *   exposing problem in Boost.Spirit.Karma's signed integer output
 *   generators from Boost.Fusion adapted ADTs.
 *
 * Copyright (C) 2011 Torsten Maehne
 *
 * 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)
 */

/*!
 * \file    test_signed_integer_output_with_karma_minimal.cpp
 *
 * \brief   Minimal test of signed integer output from Boost.Fusion
 *          adapted ADTs and structs with Boost.Spirit.Karma rules.
 *
 * Boost.Spirit.Karma output rules should show the same behavior for
 * Boost.Fusion-adapted structs (direct access of the public member
 * variables) and ADTs (access to the private member variables via
 * getters and setters). This has been the case in Boost 1.44 and is
 * demonstrated in this test case for rational number ADTs and
 * structs, which use signed integer member variables.
 *
 * Compilation of this test case against Boost 1.45.0 and 1.46.1 will
 * fail. Compilation against Boost 1.47.0 and 1.48.0 will succeed, but
 * the output of negative values of signed integer members of
 * Boost.Fusion-adapted ADTs will be wrong. The minus sign is output
 * correctly, but it is followed by a wrong value, which seems to be
 * yielded by a cast from a signed to an unsigned integer value
 * instead of taking the absolute value of the signed integer
 * value. This has been observed on Mac OS X 10.7.2 (x86_64) with
 * Xcode 4.2 using Apple's g++ 4.2.1, Apple's clang++
 * 3.0. Interestingly, compiling the test case against Boost 1.47.0 or
 * Boost 1.48.0 using MacPorts g++ 4.5.3, will yield a different wrong
 * output.
 *
 * Compilation against Boost from the Subversion trunk (rev. 76203)
 * succeeds, but yields the same wrong and compiler-dependent output.
 *
 * \author  Torsten Maehne
 * \date    2011-12-28
 * \version $Id$
 */
#include <iostream>
#include <sstream>
#include <boost/rational.hpp>
#include <boost/version.hpp>
#if BOOST_VERSION < 104500
// Until Boost 1.44 use BOOST_FUSION_ADAPT_CLASS
#include <boost/fusion/include/adapt_class.hpp>
#else
// Since Boost 1.45 BOOST_FUSION_ADAPT_CLASS is named BOOST_FUSION_ADAPT_ADT
#include <boost/fusion/include/adapt_adt.hpp>
#include <boost/spirit/include/support_adapt_adt_attributes.hpp>
#endif

#include <boost/fusion/include/adapt_struct.hpp>
// Include only the strictly necessary parts of Boost.Spirit.Karma to reduce compile time.
#include <boost/spirit/include/karma_char.hpp>
#include <boost/spirit/include/karma_nonterminal.hpp>
#include <boost/spirit/include/karma_numeric.hpp>
#include <boost/spirit/include/karma_operator.hpp>
#include <boost/spirit/include/karma_generate.hpp>


namespace {

//! Rational number ADT with signed integer members.
typedef boost::rational<int> rational_int_adt;

//! Rational number struct with signed integer members.
struct rational_int_struct {
  int numerator, denominator;

  explicit rational_int_struct(int num = 0, int den = 1)
  : numerator(num), denominator(den)
  {}
};

} // anonymous namespace

#if BOOST_VERSION < 104500
// Adapt class boost::rational<int> to a Fusion sequence.
BOOST_FUSION_ADAPT_CLASS(
  ::rational_int_adt,
  (int, int, obj.numerator(), obj.numerator(val))
  (int, int, obj.denominator(), obj.denominator(val))
)
#else
// Adapt ADT boost::rational<int> to a Fusion sequence.
BOOST_FUSION_ADAPT_ADT(
  ::rational_int_adt,
  (int, int, obj.numerator(), obj.numerator(val))
  (int, int, obj.denominator(), obj.denominator(val))
)
#endif

// Adapt struct ::rational_int_struct to a Fusion sequence.
BOOST_FUSION_ADAPT_STRUCT(
  ::rational_int_struct,
  (int, numerator)
  (int, denominator)
)


int main(int argc, char* argv[]) {
  // Namespace alias for Boost Spirit Karma.
  namespace karma = boost::spirit::karma;
  // Namespace alias for Boost Spirit Phoenix.
  namespace phx = boost::phoenix;

  using karma::int_;
  using boost::spirit::karma::generate;
  using std::cout;
  using std::endl;
  typedef std::ostream_iterator<char> ostr_iter_type;

  // Output iterator type used as sink for the Boost.Spirit.Karma
  // generator to the output test stream.
  ostr_iter_type ostr_iter(cout);

  //! Check the Karma generator rules for ::rational_int_adt.
  karma::rule<ostr_iter_type, rational_int_adt()> rational_int_adt_;
  rational_int_adt_.name("rational_int_adt_");
  rational_int_adt_ = int_ << '/' << int_;
  {
    cout << "rational_int_adt(2, -6) = ";
    generate(ostr_iter, rational_int_adt_, rational_int_adt(2, -6));
    cout << " (expected: -1/3)" << endl;
  }
  {
    cout << "rational_int_adt(-2, 4) = ";
    // Maybe generate doesn't like temporaries?
    rational_int_adt rat(-2, 4);
    generate(ostr_iter, rational_int_adt_, rat);
    cout << " (expected: -1/2)" << endl;
  }

  //! Check the Karma generator rules for ::rational_int_struct.
  karma::rule<ostr_iter_type, rational_int_struct()> rational_int_struct_;
  rational_int_struct_.name("rational_int_struct_");
  rational_int_struct_ = int_ << '/' << int_;
  {
    cout << "rational_int_struct(2, -6) = ";
    generate(ostr_iter, rational_int_struct_, rational_int_struct(2, -6));
    cout << " (expected: 2/-6)" << endl;
  }
  return 0;
}