ceph/src/boost/libs/test/include/boost/test/data/monomorphic/generate.hpp

   1 //  (C) Copyright Gennadiy Rozental 2001.
   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 generic interface for monomorphic dataset based on generator
  10 // ***************************************************************************
  11
  12 #ifndef BOOST_TEST_DATA_MONOMORPHIC_GENERATE_HPP_112011GER
  13 #define BOOST_TEST_DATA_MONOMORPHIC_GENERATE_HPP_112011GER
  14
  15 // Boost.Test
  16 #include <boost/test/data/config.hpp>
  17 #include <boost/test/data/monomorphic/fwd.hpp>
  18
  19 #include <boost/test/detail/suppress_warnings.hpp>
  20
  21 //____________________________________________________________________________//
  22
  23 namespace boost {
  24 namespace unit_test {
  25 namespace data {
  26 namespace monomorphic {
  27
  28 // ************************************************************************** //
  29 // **************                  generated_by                ************** //
  30 // ************************************************************************** //
  31
  32 /*!@brief Generators interface
  33  *
  34  * This class implements the dataset concept over a generator. Examples of generators are:
  35  * - xrange_t
  36  * - random_t
  37  *
  38  * The generator concept is the following:
  39  * - the type of the generated samples is given by field @c sample
  40  * - the member function @c capacity should return the size of the collection being generated (potentially infinite)
  41  * - the member function @c next should change the state of the generator to the next generated value
  42  * - the member function @c reset should put the state of the object in the same state as right after its instanciation
  43  */
  44 template<typename Generator>
  45 class generated_by {
  46 public:
  47     typedef typename Generator::sample sample;
  48
  49     enum { arity = 1 };
  50
  51     struct iterator {
  52         // Constructor
  53         explicit    iterator( Generator& gen )
  54         : m_gen( &gen )
  55         {
  56             if(m_gen->capacity() > 0) {
  57                 m_gen->reset();
  58                 ++*this;
  59             }
  60         }
  61
  62         // forward iterator interface
  63         sample const&   operator*() const   { return m_curr_sample; }
  64         void            operator++()        { m_curr_sample = m_gen->next(); }
  65
  66     private:
  67         // Data members
  68         Generator*  m_gen;
  69         sample      m_curr_sample;
  70     };
  71
  72     typedef Generator generator_type;
  73
  74     // Constructor
  75     explicit        generated_by( Generator&& G )
  76     : m_generator( std::forward<Generator>(G) )
  77     {}
  78
  79     // Move constructor
  80     generated_by( generated_by&& rhs )
  81     : m_generator( std::forward<Generator>(rhs.m_generator) )
  82     {}
  83
  84     //! Size of the underlying dataset
  85     data::size_t    size() const            { return m_generator.capacity(); }
  86
  87     //! Iterator on the beginning of the dataset
  88     iterator        begin() const           { return iterator( boost::ref(const_cast<Generator&>(m_generator)) ); }
  89
  90 private:
  91     // Data members
  92     Generator       m_generator;
  93 };
  94
  95 //____________________________________________________________________________//
  96
  97 //! A generated dataset is a dataset.
  98 template<typename Generator>
  99 struct is_dataset<generated_by<Generator>> : mpl::true_ {};
 100
 101 } // namespace monomorphic
 102 } // namespace data
 103 } // namespace unit_test
 104 } // namespace boost
 105
 106 #include <boost/test/detail/enable_warnings.hpp>
 107
 108 #endif // BOOST_TEST_DATA_MONOMORPHIC_GENERATE_HPP_112011GER
 109