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ticket 4572 - make_iterator_range_n

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This commit is contained in:
Neil Groves
2014-03-09 19:27:28 +00:00
parent f1de74a6ac
commit 70256bd8b0
3 changed files with 38 additions and 1 deletions
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6
doc/reference/utilities.qbk
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@ -132,6 +132,12 @@ namespace boost
make_iterator_range( ForwardTraversalIterator Begin,
ForwardTraversalIterator End );
// Make an iterator_range [first, boost::next(first, n) )
template< class ForwardTraversalIterator, class Integer >
iterator_range< ForwardTraversalIterator >
make_iterator_range_n( ForwardTraversalIterator first, Integer n );
template< class ForwardRange >
iterator_range< typename range_iterator<ForwardRange>::type >
make_iterator_range( ForwardRange& r );

7
include/boost/range/iterator_range_core.hpp
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@ -651,6 +651,13 @@ public:
return iterator_range<IteratorT>( Begin, End );
}
template<typename IteratorT, typename IntegerT>
inline iterator_range<IteratorT>
make_iterator_range_n(IteratorT first, IntegerT n)
{
return iterator_range<IteratorT>(first, boost::next(first, n));
}
#ifdef BOOST_NO_FUNCTION_TEMPLATE_ORDERING
template< typename Range >

26
test/iterator_range.cpp
View File

@ -213,7 +213,30 @@ namespace iterator_range_test_detail
BOOST_CHECK_EQUAL_COLLECTIONS( rng.begin(), rng.end(),
source, source + 6 );
}
void check_make_iterator_range_n()
{
std::vector<uint32_t> input;
for (uint32_t i = 0; i < 10u; ++i)
input.push_back(i);
boost::iterator_range<std::vector<uint32_t>::iterator> rng =
boost::make_iterator_range_n(boost::begin(input), 8u);
BOOST_CHECK(rng.begin() == input.begin());
BOOST_CHECK(rng.end() == input.begin() + 8);
BOOST_CHECK_EQUAL(rng.size(), 8u);
const std::vector<uint32_t>& cinput = input;
boost::iterator_range<std::vector<uint32_t>::const_iterator> crng =
boost::make_iterator_range_n(boost::begin(cinput), 8u);
BOOST_CHECK(crng.begin() == cinput.begin());
BOOST_CHECK(crng.end() == cinput.begin() + 8);
BOOST_CHECK_EQUAL(crng.size(), 8u);
}
} // namespace iterator_range_test_detail
template<typename Pred>
@ -234,6 +257,7 @@ boost::unit_test::test_suite* init_unit_test_suite( int argc, char* argv[] )
test->add(BOOST_TEST_CASE(&check_iterator_range_operator<iterator_range_test_detail::greater_or_equal>));
test->add(BOOST_TEST_CASE(&check_iterator_range_operator<iterator_range_test_detail::equal_to>));
test->add(BOOST_TEST_CASE(&check_iterator_range_operator<iterator_range_test_detail::not_equal_to>));
test->add(BOOST_TEST_CASE(&iterator_range_test_detail::check_make_iterator_range_n));
return test;
}