data/monomorphic/join.hpp

0001 //  (C) Copyright Gennadiy Rozental 2001.
0002 //  Distributed under the Boost Software License, Version 1.0.
0003 //  (See accompanying file LICENSE_1_0.txt or copy at
0004 //  http://www.boost.org/LICENSE_1_0.txt)
0005
0006 //  See http://www.boost.org/libs/test for the library home page.
0007 //
0008 //! @file
0009 //! Defines dataset join operation
0010 // ***************************************************************************
0011
0012 #ifndef BOOST_TEST_DATA_MONOMORPHIC_JOIN_HPP_112711GER
0013 #define BOOST_TEST_DATA_MONOMORPHIC_JOIN_HPP_112711GER
0014
0015 // Boost.Test
0016 #include <boost/test/data/config.hpp>
0017 #include <boost/test/data/monomorphic/fwd.hpp>
0018
0019 #include <boost/core/enable_if.hpp>
0020 #include <boost/mpl/identity.hpp>
0021
0022 #include <boost/test/detail/suppress_warnings.hpp>
0023
0024 //____________________________________________________________________________//
0025
0026 namespace boost {
0027 namespace unit_test {
0028 namespace data {
0029 namespace monomorphic {
0030
0031 // ************************************************************************** //
0032 // **************                      join                    ************** //
0033 // ************************************************************************** //
0034
0035 //! Defines a new dataset from the concatenation of two datasets
0036 //!
0037 //! The size of the resulting dataset is the sum of the two underlying datasets. The arity of the datasets
0038 //! should match.
0039 template<typename DataSet1, typename DataSet2>
0040 class join {
0041     typedef typename boost::decay<DataSet1>::type   dataset1_decay;
0042     typedef typename boost::decay<DataSet2>::type   dataset2_decay;
0043
0044     typedef typename dataset1_decay::iterator       dataset1_iter;
0045     typedef typename dataset2_decay::iterator       dataset2_iter;
0046
0047     using iter1_ret = decltype(*std::declval<DataSet1>().begin());
0048     using iter2_ret = decltype(*std::declval<DataSet2>().begin());
0049
0050 public:
0051
0052     static const int arity = dataset1_decay::arity;
0053
0054     using sample_t = typename std::conditional<
0055         std::is_reference<iter1_ret>::value && std::is_reference<iter2_ret>::value && std::is_same<iter1_ret, iter2_ret>::value,
0056         iter1_ret,
0057         typename std::remove_reference<iter1_ret>::type
0058         >::type
0059         ;
0060
0061     struct iterator {
0062         // Constructor
0063         explicit    iterator( dataset1_iter&& it1, dataset2_iter&& it2, data::size_t first_size )
0064         : m_it1( std::move( it1 ) )
0065         , m_it2( std::move( it2 ) )
0066         , m_first_size( first_size )
0067         {}
0068
0069         // forward iterator interface
0070         // The returned sample should be by value, as the operator* may return a temporary object
0071         sample_t     operator*() const   { return m_first_size > 0 ? *m_it1 : *m_it2; }
0072         void         operator++()        { if( m_first_size > 0 ) { --m_first_size; ++m_it1; } else ++m_it2; }
0073
0074     private:
0075         // Data members
0076         dataset1_iter       m_it1;
0077         dataset2_iter       m_it2;
0078         data::size_t        m_first_size;
0079     };
0080
0081     //! Constructor
0082     join( DataSet1&& ds1, DataSet2&& ds2 )
0083     : m_ds1( std::forward<DataSet1>( ds1 ) )
0084     , m_ds2( std::forward<DataSet2>( ds2 ) )
0085     {}
0086
0087     //! Move constructor
0088     join( join&& j )
0089     : m_ds1( std::forward<DataSet1>( j.m_ds1 ) )
0090     , m_ds2( std::forward<DataSet2>( j.m_ds2 ) )
0091     {}
0092
0093     //! dataset interface
0094     data::size_t    size() const    { return m_ds1.size() + m_ds2.size(); }
0095     iterator        begin() const   { return iterator( m_ds1.begin(), m_ds2.begin(), m_ds1.size() ); }
0096
0097 private:
0098     // Data members
0099     DataSet1        m_ds1;
0100     DataSet2        m_ds2;
0101 };
0102
0103 //____________________________________________________________________________//
0104
0105 // A joined dataset  is a dataset.
0106 template<typename DataSet1, typename DataSet2>
0107 struct is_dataset<join<DataSet1,DataSet2>> : mpl::true_ {};
0108
0109 //____________________________________________________________________________//
0110
0111 namespace result_of {
0112
0113 //! Result type of the join operation on datasets.
0114 template<typename DataSet1Gen, typename DataSet2Gen>
0115 struct join {
0116     typedef monomorphic::join<typename DataSet1Gen::type,typename DataSet2Gen::type> type;
0117 };
0118
0119 } // namespace result_of
0120
0121 //____________________________________________________________________________//
0122
0123 template<typename DataSet1, typename DataSet2>
0124 inline typename boost::lazy_enable_if_c<is_dataset<DataSet1>::value && is_dataset<DataSet2>::value,
0125                                         result_of::join<mpl::identity<DataSet1>,mpl::identity<DataSet2>>
0126 >::type
0127 operator+( DataSet1&& ds1, DataSet2&& ds2 )
0128 {
0129     return join<DataSet1,DataSet2>( std::forward<DataSet1>( ds1 ),  std::forward<DataSet2>( ds2 ) );
0130 }
0131
0132 //____________________________________________________________________________//
0133
0134 template<typename DataSet1, typename DataSet2>
0135 inline typename boost::lazy_enable_if_c<is_dataset<DataSet1>::value && !is_dataset<DataSet2>::value,
0136                                         result_of::join<mpl::identity<DataSet1>,data::result_of::make<DataSet2>>
0137 >::type
0138 operator+( DataSet1&& ds1, DataSet2&& ds2 )
0139 {
0140     return std::forward<DataSet1>( ds1 ) + data::make( std::forward<DataSet2>( ds2 ) );
0141 }
0142
0143 //____________________________________________________________________________//
0144
0145 template<typename DataSet1, typename DataSet2>
0146 inline typename boost::lazy_enable_if_c<!is_dataset<DataSet1>::value && is_dataset<DataSet2>::value,
0147                                         result_of::join<data::result_of::make<DataSet1>,mpl::identity<DataSet2>>
0148 >::type
0149 operator+( DataSet1&& ds1, DataSet2&& ds2 )
0150 {
0151     return data::make( std::forward<DataSet1>(ds1) ) + std::forward<DataSet2>( ds2 );
0152 }
0153
0154 } // namespace monomorphic
0155 } // namespace data
0156 } // namespace unit_test
0157 } // namespace boost
0158
0159 #include <boost/test/detail/enable_warnings.hpp>
0160
0161 #endif // BOOST_TEST_DATA_MONOMORPHIC_JOIN_HPP_112711GER
0162