boost/libs/range/test/algorithm_test/search_n.cpp

// Boost.Range library
//
//  Copyright Neil Groves 2009. Use, modification and
//  distribution is subject to 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)
//
//
// For more information, see http://www.boost.org/libs/range/
//
#include <boost/range/algorithm/search_n.hpp>

#include <boost/test/test_tools.hpp>
#include <boost/test/unit_test.hpp>

#include <boost/assign.hpp>
#include <algorithm>
#include <list>
#include <set>
#include <vector>

namespace
{
    template<typename ForwardIterator, typename Integer, typename Value>
    inline ForwardIterator
    reference_search_n(ForwardIterator first, ForwardIterator last,
                       Integer count, const Value& value)
    {
        if (count <= 0)
            return first;
        else if (count == 1)
            return std::find(first, last, value);
        else
        {
            first = std::find(first, last, value);
            while (first != last)
            {
                typename std::iterator_traits<ForwardIterator>::difference_type n = count;
                ForwardIterator i = first;
                ++i;
                while (i != last && n != 1 && *i==value)
                {
                    ++i;
                    --n;
                }
                if (n == 1)
                    return first;
                if (i == last)
                    return last;
                first = std::find(++i, last, value);
            }
        }
        return last;
    }

    template<typename ForwardIterator, typename Integer, typename Value,
             typename BinaryPredicate>
    inline ForwardIterator
    reference_search_n(ForwardIterator first, ForwardIterator last,
                       Integer count, const Value& value,
                       BinaryPredicate pred)
    {
        typedef typename std::iterator_traits<
            ForwardIterator
        >::iterator_category cat_t BOOST_RANGE_UNUSED;

        if (count <= 0)
            return first;
        if (count == 1)
        {
            while (first != last && !static_cast<bool>(pred(*first, value)))
                ++first;
            return first;
        }
        else
        {
            typedef typename std::iterator_traits<ForwardIterator>::difference_type difference_t;

            while (first != last && !static_cast<bool>(pred(*first, value)))
                ++first;

            while (first != last)
            {
                difference_t n = count;
                ForwardIterator i = first;
                ++i;
                while (i != last && n != 1 && static_cast<bool>(pred(*i, value)))
                {
                    ++i;
                    --n;
                }
                if (n == 1)
                    return first;
                if (i == last)
                    return last;
                first = ++i;
                while (first != last && !static_cast<bool>(pred(*first, value)))
                    ++first;
            }
        }
        return last;
    }

    template< class Container1, class Value, class Pred >
    void test_search_n_pred_impl(Container1& cont1, Value value, Pred pred)
    {
        typedef BOOST_DEDUCED_TYPENAME Container1::const_iterator const_iterator1_t;
        typedef BOOST_DEDUCED_TYPENAME Container1::iterator iterator1_t;

        const Container1& ccont1 = cont1;

        for (std::size_t n = 0; n < cont1.size(); ++n)
        {
            iterator1_t it = boost::search_n(cont1, n, value, pred);
            BOOST_CHECK( it == boost::search_n(boost::make_iterator_range(cont1), n, value, pred) );
            BOOST_CHECK( it == reference_search_n(cont1.begin(), cont1.end(), n, value, pred) );

            const_iterator1_t cit = boost::search_n(ccont1, n, value, pred);
            BOOST_CHECK( cit == boost::search_n(boost::make_iterator_range(ccont1), n, value, pred) );
            BOOST_CHECK( cit == reference_search_n(ccont1.begin(), ccont1.end(), n, value, pred) );
        }
    }

    template< class Container1, class Value >
    void test_search_n_impl(Container1& cont1, Value value)
    {
        typedef BOOST_DEDUCED_TYPENAME Container1::const_iterator const_iterator1_t;
        typedef BOOST_DEDUCED_TYPENAME Container1::iterator iterator1_t;

        const Container1& ccont1 = cont1;

        for (std::size_t n = 0; n < cont1.size(); ++n)
        {
            iterator1_t it = boost::search_n(cont1, n, value);
            BOOST_CHECK( it == boost::search_n(boost::make_iterator_range(cont1), n, value) );
            BOOST_CHECK( it == reference_search_n(cont1.begin(), cont1.end(), n, value) );

            const_iterator1_t cit = boost::search_n(ccont1, n, value);
            BOOST_CHECK( cit == boost::search_n(boost::make_iterator_range(ccont1), n, value) );
            BOOST_CHECK( cit == reference_search_n(ccont1.begin(), ccont1.end(), n, value) );
        }

        test_search_n_pred_impl(cont1, value, std::less<int>());
        test_search_n_pred_impl(cont1, value, std::greater<int>());
        test_search_n_pred_impl(cont1, value, std::equal_to<int>());
        test_search_n_pred_impl(cont1, value, std::not_equal_to<int>());
    }

    template< class Container1, class Container2 >
    void test_search_n_impl()
    {
        using namespace boost::assign;

        Container1 cont1;

        test_search_n_impl(cont1, 1);

        cont1 += 1;
        test_search_n_impl(cont1, 1);
        test_search_n_impl(cont1, 0);

        cont1.clear();
        cont1 += 1,1;
        test_search_n_impl(cont1, 1);
        test_search_n_impl(cont1, 0);

        cont1 += 1,1,1;
        test_search_n_impl(cont1, 1);
        test_search_n_impl(cont1, 0);

        cont1.clear();
        cont1 += 1,2,3,4,5,6,7,8,9;
        test_search_n_impl(cont1, 1);
        test_search_n_impl(cont1, 2);
        test_search_n_impl(cont1, 5);
        test_search_n_impl(cont1, 9);
    }

    void test_search_n()
    {
        test_search_n_impl< std::list<int>, std::list<int> >();
        test_search_n_impl< std::vector<int>, std::vector<int> >();
        test_search_n_impl< std::set<int>, std::set<int> >();
        test_search_n_impl< std::list<int>, std::vector<int> >();
        test_search_n_impl< std::vector<int>, std::list<int> >();
    }
}

boost::unit_test::test_suite*
init_unit_test_suite(int argc, char* argv[])
{
    boost::unit_test::test_suite* test
        = BOOST_TEST_SUITE( "RangeTestSuite.algorithm.search_n" );

    test->add( BOOST_TEST_CASE( &test_search_n ) );

    return test;
}