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//! Input iterator facade
10// ***************************************************************************
11
12#ifndef BOOST_TEST_UTILS_INPUT_ITERATOR_FACADE_HPP
13#define BOOST_TEST_UTILS_INPUT_ITERATOR_FACADE_HPP
14
15// Boost
16#include <boost/iterator/iterator_facade.hpp>
17
18#include <boost/test/detail/suppress_warnings.hpp>
19
20//____________________________________________________________________________//
21
22namespace boost {
23namespace unit_test {
24namespace utils {
25
26// ************************************************************************** //
27// ************** input_iterator_core_access ************** //
28// ************************************************************************** //
29
30class input_iterator_core_access
31{
32#if defined(BOOST_NO_MEMBER_TEMPLATE_FRIENDS) || BOOST_WORKAROUND(__BORLANDC__, BOOST_TESTED_AT(0x551))
33public:
34#else
35 template <class I, class V, class R, class TC> friend class input_iterator_facade;
36#endif
37
38 template <class Facade>
39 static bool get( Facade& f )
40 {
41 return f.get();
42 }
43
44private:
45 // objects of this class are useless
46 input_iterator_core_access(); //undefined
47};
48
49// ************************************************************************** //
50// ************** input_iterator_facade ************** //
51// ************************************************************************** //
52
53template<typename Derived,
54 typename ValueType,
55 typename Reference = ValueType const&,
56 typename Traversal = single_pass_traversal_tag>
57class input_iterator_facade : public iterator_facade<Derived,ValueType,Traversal,Reference>
58{
59public:
60 // Constructor
61 input_iterator_facade() : m_valid( false ), m_value() {}
62
63protected: // provide access to the Derived
64 void init()
65 {
66 m_valid = true;
67 increment();
68 }
69
70 // Data members
71 mutable bool m_valid;
72 ValueType m_value;
73
74private:
75 friend class boost::iterator_core_access;
76
77 // iterator facade interface implementation
78 void increment()
79 {
80 // we make post-end incrementation indefinetly safe
81 if( m_valid )
82 m_valid = input_iterator_core_access::get( *static_cast<Derived*>(this) );
83 }
84 Reference dereference() const
85 {
86 return m_value;
87 }
88
89 // iterator facade interface implementation
90 bool equal( input_iterator_facade const& rhs ) const
91 {
92 // two invalid iterator equals, inequal otherwise
93 return !m_valid && !rhs.m_valid;
94 }
95};
96
97} // namespace utils
98} // namespace unit_test
99} // namespace boost
100
101//____________________________________________________________________________//
102
103#include <boost/test/detail/enable_warnings.hpp>
104
105#endif // BOOST_TEST_UTILS_INPUT_ITERATOR_FACADE_HPP
106

source code of boost/boost/test/utils/iterator/input_iterator_facade.hpp