ceph/src/boost/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/core/ref.hpp>
  20
  21 #include <boost/test/detail/suppress_warnings.hpp>
  22
  23 //____________________________________________________________________________//
  24
  25 namespace boost {
  26 namespace unit_test {
  27 namespace data {
  28 namespace monomorphic {
  29
  30 // ************************************************************************** //
  31 // **************                  generated_by                ************** //
  32 // ************************************************************************** //
  33
  34 /*!@brief Generators interface
  35  *
  36  * This class implements the dataset concept over a generator. Examples of generators are:
  37  * - xrange_t
  38  * - random_t
  39  *
  40  * The generator concept is the following:
  41  * - the type of the generated samples is given by field @c sample
  42  * - the member function @c capacity should return the size of the collection being generated (potentially infinite)
  43  * - the member function @c next should change the state of the generator to the next generated value
  44  * - the member function @c reset should put the state of the object in the same state as right after its instanciation
  45  */
  46 template<typename Generator>
  47 class generated_by {
  48 public:
  49     typedef typename Generator::sample sample;
  50
  51     enum { arity = 1 };
  52
  53     struct iterator {
  54         // Constructor
  55         explicit    iterator( Generator& gen )
  56         : m_gen( &gen )
  57         {
  58             if(m_gen->capacity() > 0) {
  59                 m_gen->reset();
  60                 ++*this;
  61             }
  62         }
  63
  64         // forward iterator interface
  65         sample const&   operator*() const   { return m_curr_sample; }
  66         void            operator++()        { m_curr_sample = m_gen->next(); }
  67
  68     private:
  69         // Data members
  70         Generator*  m_gen;
  71         sample      m_curr_sample;
  72     };
  73
  74     typedef Generator generator_type;
  75
  76     // Constructor
  77     explicit        generated_by( Generator&& G )
  78     : m_generator( std::forward<Generator>(G) )
  79     {}
  80
  81     // Move constructor
  82     generated_by( generated_by&& rhs )
  83     : m_generator( std::forward<Generator>(rhs.m_generator) )
  84     {}
  85
  86     //! Size of the underlying dataset
  87     data::size_t    size() const            { return m_generator.capacity(); }
  88
  89     //! Iterator on the beginning of the dataset
  90     iterator        begin() const           { return iterator( boost::ref(const_cast<Generator&>(m_generator)) ); }
  91
  92 private:
  93     // Data members
  94     Generator       m_generator;
  95 };
  96
  97 //____________________________________________________________________________//
  98
  99 //! A generated dataset is a dataset.
 100 template<typename Generator>
 101 struct is_dataset<generated_by<Generator>> : mpl::true_ {};
 102
 103 } // namespace monomorphic
 104 } // namespace data
 105 } // namespace unit_test
 106 } // namespace boost
 107
 108 #include <boost/test/detail/enable_warnings.hpp>
 109
 110 #endif // BOOST_TEST_DATA_MONOMORPHIC_GENERATE_HPP_112011GER
 111