ceph/src/boost/boost/test/data/monomorphic/delayed.hpp

   1 //  (C) Copyright Raffi Enficiaud 2018.
   2 //  Distributed under the Boost Software License, Version 1.0.
   3 //  (See accompanying file LICENSE_1_0.txt or copy at
   4 //  http://www.boost.org/LICENSE_1_0.txt)
   5
   6 //  See http://www.boost.org/libs/test for the library home page.
   7 //
   8 /// @file
   9 /// Defines a lazy/delayed dataset store
  10 // ***************************************************************************
  11
  12 #ifndef BOOST_TEST_DATA_MONOMORPHIC_DELAYED_HPP_062018GER
  13 #define BOOST_TEST_DATA_MONOMORPHIC_DELAYED_HPP_062018GER
  14
  15 // Boost.Test
  16 #include <boost/test/data/config.hpp>
  17 #include <boost/test/data/monomorphic/fwd.hpp>
  18 #include <boost/test/data/index_sequence.hpp>
  19
  20 #include <boost/core/ref.hpp>
  21
  22 #include <algorithm>
  23 #include <memory>
  24
  25 #include <boost/test/detail/suppress_warnings.hpp>
  26
  27 //____________________________________________________________________________//
  28
  29 #if !defined(BOOST_NO_CXX11_VARIADIC_TEMPLATES) && \
  30     !defined(BOOST_NO_CXX11_HDR_TUPLE)
  31
  32 namespace boost {
  33 namespace unit_test {
  34 namespace data {
  35 namespace monomorphic {
  36
  37 // ************************************************************************** //
  38 // **************               delayed_dataset                ************** //
  39 // ************************************************************************** //
  40
  41
  42 /// Delayed dataset
  43 ///
  44 /// This dataset holds another dataset that is instanciated on demand. It is
  45 /// constructed with the @c data::make_delayed<dataset_t>(arg1,....) instead of the
  46 /// @c data::make.
  47 template <class dataset_t, class ...Args>
  48 class delayed_dataset
  49 {
  50 public:
  51     enum { arity = dataset_t::arity };
  52     using iterator = decltype(std::declval<dataset_t>().begin());
  53
  54     delayed_dataset(Args... args)
  55     : m_args(std::make_tuple(std::forward<Args>(args)...))
  56     {}
  57
  58     // Mostly for VS2013
  59     delayed_dataset(delayed_dataset&& b)
  60     : m_args(std::move(b.m_args))
  61     , m_dataset(std::move(b.m_dataset))
  62     {}
  63
  64     boost::unit_test::data::size_t size() const {
  65         return this->get().size();
  66     }
  67
  68     // iterator
  69     iterator begin() const {
  70         return this->get().begin();
  71     }
  72
  73 private:
  74
  75   dataset_t& get() const {
  76       if(!m_dataset) {
  77           m_dataset = create(boost::unit_test::data::index_sequence_for<Args...>());
  78       }
  79       return *m_dataset;
  80   }
  81
  82   template<std::size_t... I>
  83   std::unique_ptr<dataset_t>
  84   create(boost::unit_test::data::index_sequence<I...>) const
  85   {
  86       return std::unique_ptr<dataset_t>{new dataset_t(std::get<I>(m_args)...)};
  87   }
  88
  89   std::tuple<typename std::decay<Args>::type...> m_args;
  90   mutable std::unique_ptr<dataset_t> m_dataset;
  91 };
  92
  93 //____________________________________________________________________________//
  94
  95 //! A lazy/delayed dataset is a dataset.
  96 template <class dataset_t, class ...Args>
  97 struct is_dataset< delayed_dataset<dataset_t, Args...> > : boost::mpl::true_ {};
  98
  99 //____________________________________________________________________________//
 100
 101 } // namespace monomorphic
 102
 103
 104 //! Delayed dataset instanciation
 105 template<class dataset_t, class ...Args>
 106 inline typename std::enable_if<
 107   monomorphic::is_dataset< dataset_t >::value,
 108   monomorphic::delayed_dataset<dataset_t, Args...>
 109 >::type
 110 make_delayed(Args... args)
 111 {
 112     return monomorphic::delayed_dataset<dataset_t, Args...>( std::forward<Args>(args)... );
 113 }
 114
 115
 116 } // namespace data
 117 } // namespace unit_test
 118 } // namespace boost
 119
 120 #endif
 121
 122 #include <boost/test/detail/enable_warnings.hpp>
 123
 124 #endif // BOOST_TEST_DATA_MONOMORPHIC_DELAYED_HPP_062018GER