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// Copyright 2010 (c) Dean Michael Berris
// Distributed under the Boost Software License Version 1.0.
// (See accompanying file LICENSE_1_0.txt or copy at
// http://www.boost.org/LICENSE_1_0.txt)
#include <cstddef>
#include <algorithm>
#include <iterator>
#include <vector>
#include <boost/config.hpp>
#if !defined(BOOST_NO_CXX11_DECLTYPE)
// Force boost::result_of use decltype, even on compilers that don't support N3276.
// This enables this test to also verify if the iterator works with lambdas
// on such compilers with this config macro. Note that without the macro result_of
// (and consequently the iterator) is guaranteed to _not_ work, so this case is not
// worth testing anyway.
#define BOOST_RESULT_OF_USE_DECLTYPE
#endif
#include <boost/core/lightweight_test.hpp>
#include <boost/iterator/function_input_iterator.hpp>
namespace {
struct ones {
typedef int result_type;
result_type operator() () {
return 1;
}
};
int ones_function () {
return 1;
}
struct counter {
typedef int result_type;
int n;
explicit counter(int n_) : n(n_) { }
result_type operator() () {
return n++;
}
};
} // namespace
using namespace std;
int main()
{
// test the iterator with function objects
ones ones_generator;
vector<int> values(10);
generate(values.begin(), values.end(), ones());
vector<int> generated;
copy(
boost::make_function_input_iterator(ones_generator, 0),
boost::make_function_input_iterator(ones_generator, 10),
back_inserter(generated)
);
BOOST_TEST_ALL_EQ(values.begin(), values.end(), generated.begin(), generated.end());
// test the iterator with normal functions
vector<int>().swap(generated);
copy(
boost::make_function_input_iterator(&ones_function, 0),
boost::make_function_input_iterator(&ones_function, 10),
back_inserter(generated)
);
BOOST_TEST_ALL_EQ(values.begin(), values.end(), generated.begin(), generated.end());
// test the iterator with a reference to a function
vector<int>().swap(generated);
copy(
boost::make_function_input_iterator(ones_function, 0),
boost::make_function_input_iterator(ones_function, 10),
back_inserter(generated)
);
BOOST_TEST_ALL_EQ(values.begin(), values.end(), generated.begin(), generated.end());
// test the iterator with a stateful function object
counter counter_generator(42);
vector<int>().swap(generated);
copy(
boost::make_function_input_iterator(counter_generator, 0),
boost::make_function_input_iterator(counter_generator, 10),
back_inserter(generated)
);
BOOST_TEST_EQ(generated.size(), 10u);
BOOST_TEST_EQ(counter_generator.n, 42 + 10);
for(std::size_t i = 0; i != 10; ++i)
BOOST_TEST_EQ(generated[i], static_cast<int>(42 + i));
// Test that incrementing the iterator returns a reference to the iterator type
{
typedef boost::iterators::function_input_iterator<counter, int> function_counter_iterator_t;
function_counter_iterator_t it1(counter_generator, 0);
function_counter_iterator_t it2(++it1);
function_counter_iterator_t it3(it2++);
BOOST_TEST_EQ(*it3, 54);
}
#if !defined(BOOST_NO_CXX11_LAMBDAS) && !defined(BOOST_NO_CXX11_AUTO_DECLARATIONS) \
&& defined(BOOST_RESULT_OF_USE_DECLTYPE)
// test the iterator with lambda expressions
int num = 42;
auto lambda_generator = [&num] { return num++; };
vector<int>().swap(generated);
copy(
boost::make_function_input_iterator(lambda_generator, 0),
boost::make_function_input_iterator(lambda_generator, 10),
back_inserter(generated)
);
BOOST_TEST_EQ(generated.size(), 10u);
for(std::size_t i = 0; i != 10; ++i)
BOOST_TEST_EQ(generated[i], static_cast<int>(42 + i));
#endif // BOOST_NO_CXX11_LAMBDAS
return boost::report_errors();
}
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