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;
operator ()__anon82049ada0111::ones30 result_type operator() () {
31 return 1;
32 }
33 };
34
ones_function()35 int ones_function () {
36 return 1;
37 }
38
39 struct counter {
40 typedef int result_type;
41 int n;
counter__anon82049ada0111::counter42 explicit counter(int n_) : n(n_) { }
operator ()__anon82049ada0111::counter43 result_type operator() () {
44 return n++;
45 }
46 };
47
48 } // namespace
49
50 using namespace std;
51
main()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 }
121