ceph/src/boost/libs/iterator/test/function_input_iterator_test.cpp

   1 // Copyright 2010 (c) Dean Michael Berris
   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 #include <cstddef>
   7
   8 #include <algorithm>
   9 #include <iterator>
  10 #include <vector>
  11
  12 #include <boost/config.hpp>
  13
  14 #if !defined(BOOST_NO_CXX11_DECLTYPE)
  15 // Force boost::result_of use decltype, even on compilers that don't support N3276.
  16 // This enables this test to also verify if the iterator works with lambdas
  17 // on such compilers with this config macro. Note that without the macro result_of
  18 // (and consequently the iterator) is guaranteed to _not_ work, so this case is not
  19 // worth testing anyway.
  20 #define BOOST_RESULT_OF_USE_DECLTYPE
  21 #endif
  22
  23 #include <boost/core/lightweight_test.hpp>
  24 #include <boost/iterator/function_input_iterator.hpp>
  25
  26 namespace {
  27
  28 struct ones {
  29     typedef int result_type;
  30     result_type operator() () {
  31         return 1;
  32     }
  33 };
  34
  35 int ones_function () {
  36     return 1;
  37 }
  38
  39 struct counter {
  40     typedef int result_type;
  41     int n;
  42     explicit counter(int n_) : n(n_) { }
  43     result_type operator() () {
  44         return n++;
  45     }
  46 };
  47
  48 } // namespace
  49
  50 using namespace std;
  51
  52 int main()
  53 {
  54     // test the iterator with function objects
  55     ones ones_generator;
  56     vector<int> values(10);
  57     generate(values.begin(), values.end(), ones());
  58
  59     vector<int> generated;
  60     copy(
  61         boost::make_function_input_iterator(ones_generator, 0),
  62         boost::make_function_input_iterator(ones_generator, 10),
  63         back_inserter(generated)
  64         );
  65
  66     BOOST_TEST_ALL_EQ(values.begin(), values.end(), generated.begin(), generated.end());
  67
  68     // test the iterator with normal functions
  69     vector<int>().swap(generated);
  70     copy(
  71         boost::make_function_input_iterator(&ones_function, 0),
  72         boost::make_function_input_iterator(&ones_function, 10),
  73         back_inserter(generated)
  74         );
  75
  76     BOOST_TEST_ALL_EQ(values.begin(), values.end(), generated.begin(), generated.end());
  77
  78     // test the iterator with a reference to a function
  79     vector<int>().swap(generated);
  80     copy(
  81         boost::make_function_input_iterator(ones_function, 0),
  82         boost::make_function_input_iterator(ones_function, 10),
  83         back_inserter(generated)
  84         );
  85
  86     BOOST_TEST_ALL_EQ(values.begin(), values.end(), generated.begin(), generated.end());
  87
  88     // test the iterator with a stateful function object
  89     counter counter_generator(42);
  90     vector<int>().swap(generated);
  91     copy(
  92         boost::make_function_input_iterator(counter_generator, 0),
  93         boost::make_function_input_iterator(counter_generator, 10),
  94         back_inserter(generated)
  95         );
  96
  97     BOOST_TEST_EQ(generated.size(), 10u);
  98     BOOST_TEST_EQ(counter_generator.n, 42 + 10);
  99     for(std::size_t i = 0; i != 10; ++i)
 100         BOOST_TEST_EQ(generated[i], static_cast<int>(42 + i));
 101
 102 #if !defined(BOOST_NO_CXX11_LAMBDAS) && !defined(BOOST_NO_CXX11_AUTO_DECLARATIONS) \
 103     && defined(BOOST_RESULT_OF_USE_DECLTYPE)
 104     // test the iterator with lambda expressions
 105     int num = 42;
 106     auto lambda_generator = [&num] { return num++; };
 107     vector<int>().swap(generated);
 108     copy(
 109         boost::make_function_input_iterator(lambda_generator, 0),
 110         boost::make_function_input_iterator(lambda_generator, 10),
 111         back_inserter(generated)
 112         );
 113
 114     BOOST_TEST_EQ(generated.size(), 10u);
 115     for(std::size_t i = 0; i != 10; ++i)
 116         BOOST_TEST_EQ(generated[i], static_cast<int>(42 + i));
 117 #endif // BOOST_NO_CXX11_LAMBDAS
 118
 119     return boost::report_errors();
 120 }