libs/iterator/test/is_readable_iterator.cpp

   1 // Copyright David Abrahams 2003. Use, modification and distribution is
   2 // subject to the Boost Software License, Version 1.0. (See accompanying
   3 // file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
   4
   5 #include <deque>
   6 #include <iterator>
   7 #include <iostream>
   8 #include <boost/static_assert.hpp>
   9 #include <boost/noncopyable.hpp>
  10 #include <boost/iterator/is_readable_iterator.hpp>
  11 #include <boost/iterator.hpp>
  12
  13 // Last, for BOOST_NO_LVALUE_RETURN_DETECTION
  14 #include <boost/iterator/detail/config_def.hpp>
  15
  16 struct v
  17 {
  18     v();
  19     ~v();
  20 };
  21
  22
  23 struct value_iterator : boost::iterator<std::input_iterator_tag,v>
  24 {
  25     v operator*() const;
  26 };
  27
  28 struct noncopyable_iterator : boost::iterator<std::forward_iterator_tag,boost::noncopyable>
  29 {
  30     boost::noncopyable const& operator*() const;
  31 };
  32
  33 struct proxy_iterator : boost::iterator<std::output_iterator_tag,v>
  34 {
  35 #if BOOST_WORKAROUND(__GNUC__, == 2)
  36     typedef boost::iterator<std::input_iterator_tag,v> base;
  37     typedef base::iterator_category iterator_category;
  38     typedef base::value_type value_type;
  39     typedef base::difference_type difference_type;
  40     typedef base::pointer pointer;
  41     typedef base::reference reference;
  42 #endif
  43
  44     struct proxy
  45     {
  46         operator v&();
  47         proxy& operator=(v) const;
  48     };
  49
  50     proxy operator*() const;
  51 };
  52
  53 struct proxy_iterator2 : boost::iterator<std::output_iterator_tag,v>
  54 {
  55 #if BOOST_WORKAROUND(__GNUC__, == 2)
  56     typedef boost::iterator<std::input_iterator_tag,v> base;
  57     typedef base::iterator_category iterator_category;
  58     typedef base::value_type value_type;
  59     typedef base::difference_type difference_type;
  60     typedef base::pointer pointer;
  61     typedef base::reference reference;
  62 #endif
  63
  64     struct proxy
  65     {
  66         proxy& operator=(v) const;
  67     };
  68
  69     proxy operator*() const;
  70 };
  71
  72
  73 int main()
  74 {
  75     BOOST_STATIC_ASSERT(boost::is_readable_iterator<v*>::value);
  76     BOOST_STATIC_ASSERT(boost::is_readable_iterator<v const*>::value);
  77     BOOST_STATIC_ASSERT(boost::is_readable_iterator<std::deque<v>::iterator>::value);
  78     BOOST_STATIC_ASSERT(boost::is_readable_iterator<std::deque<v>::const_iterator>::value);
  79     BOOST_STATIC_ASSERT(!boost::is_readable_iterator<std::back_insert_iterator<std::deque<v> > >::value);
  80     BOOST_STATIC_ASSERT(!boost::is_readable_iterator<std::ostream_iterator<v> >::value);
  81     BOOST_STATIC_ASSERT(boost::is_readable_iterator<proxy_iterator>::value);
  82     BOOST_STATIC_ASSERT(!boost::is_readable_iterator<proxy_iterator2>::value);
  83     BOOST_STATIC_ASSERT(boost::is_readable_iterator<value_iterator>::value);
  84
  85     // Make sure inaccessible copy constructor doesn't prevent
  86     // readability
  87     BOOST_STATIC_ASSERT(boost::is_readable_iterator<noncopyable_iterator>::value);
  88
  89     return 0;
  90 }