// 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/ | |
// | |
#ifndef BOOST_RANGE_ALGORITHM_EQUAL_HPP_INCLUDED | |
#define BOOST_RANGE_ALGORITHM_EQUAL_HPP_INCLUDED | |
#include <boost/config.hpp> | |
#include <boost/range/concepts.hpp> | |
#include <iterator> | |
namespace boost | |
{ | |
namespace range_detail | |
{ | |
// An implementation of equality comparison that is optimized for iterator | |
// traversal categories less than RandomAccessTraversal. | |
template< class SinglePassTraversalReadableIterator1, | |
class SinglePassTraversalReadableIterator2, | |
class IteratorCategoryTag1, | |
class IteratorCategoryTag2 > | |
inline bool equal_impl( SinglePassTraversalReadableIterator1 first1, | |
SinglePassTraversalReadableIterator1 last1, | |
SinglePassTraversalReadableIterator2 first2, | |
SinglePassTraversalReadableIterator2 last2, | |
IteratorCategoryTag1, | |
IteratorCategoryTag2 ) | |
{ | |
do | |
{ | |
// If we have reached the end of the left range then this is | |
// the end of the loop. They are equal if and only if we have | |
// simultaneously reached the end of the right range. | |
if (first1 == last1) | |
return first2 == last2; | |
// If we have reached the end of the right range at this line | |
// it indicates that the right range is shorter than the left | |
// and hence the result is false. | |
if (first2 == last2) | |
return false; | |
// continue looping if and only if the values are equal | |
} while(*first1++ == *first2++); | |
// Reaching this line in the algorithm indicates that a value | |
// inequality has been detected. | |
return false; | |
} | |
template< class SinglePassTraversalReadableIterator1, | |
class SinglePassTraversalReadableIterator2, | |
class IteratorCategoryTag1, | |
class IteratorCategoryTag2, | |
class BinaryPredicate > | |
inline bool equal_impl( SinglePassTraversalReadableIterator1 first1, | |
SinglePassTraversalReadableIterator1 last1, | |
SinglePassTraversalReadableIterator2 first2, | |
SinglePassTraversalReadableIterator2 last2, | |
BinaryPredicate pred, | |
IteratorCategoryTag1, | |
IteratorCategoryTag2 ) | |
{ | |
do | |
{ | |
// If we have reached the end of the left range then this is | |
// the end of the loop. They are equal if and only if we have | |
// simultaneously reached the end of the right range. | |
if (first1 == last1) | |
return first2 == last2; | |
// If we have reached the end of the right range at this line | |
// it indicates that the right range is shorter than the left | |
// and hence the result is false. | |
if (first2 == last2) | |
return false; | |
// continue looping if and only if the values are equal | |
} while(pred(*first1++, *first2++)); | |
// Reaching this line in the algorithm indicates that a value | |
// inequality has been detected. | |
return false; | |
} | |
// An implementation of equality comparison that is optimized for | |
// random access iterators. | |
template< class RandomAccessTraversalReadableIterator1, | |
class RandomAccessTraversalReadableIterator2 > | |
inline bool equal_impl( RandomAccessTraversalReadableIterator1 first1, | |
RandomAccessTraversalReadableIterator1 last1, | |
RandomAccessTraversalReadableIterator2 first2, | |
RandomAccessTraversalReadableIterator2 last2, | |
std::random_access_iterator_tag, | |
std::random_access_iterator_tag ) | |
{ | |
return ((last1 - first1) == (last2 - first2)) | |
&& std::equal(first1, last1, first2); | |
} | |
template< class RandomAccessTraversalReadableIterator1, | |
class RandomAccessTraversalReadableIterator2, | |
class BinaryPredicate > | |
inline bool equal_impl( RandomAccessTraversalReadableIterator1 first1, | |
RandomAccessTraversalReadableIterator1 last1, | |
RandomAccessTraversalReadableIterator2 first2, | |
RandomAccessTraversalReadableIterator2 last2, | |
BinaryPredicate pred ) | |
{ | |
return ((last1 - first1) == (last2 - first2)) | |
&& std::equal(first1, last1, first2, pred); | |
} | |
template< class SinglePassTraversalReadableIterator1, | |
class SinglePassTraversalReadableIterator2 > | |
inline bool equal( SinglePassTraversalReadableIterator1 first1, | |
SinglePassTraversalReadableIterator1 last1, | |
SinglePassTraversalReadableIterator2 first2, | |
SinglePassTraversalReadableIterator2 last2 ) | |
{ | |
BOOST_DEDUCED_TYPENAME std::iterator_traits< SinglePassTraversalReadableIterator1 >::iterator_category tag1; | |
BOOST_DEDUCED_TYPENAME std::iterator_traits< SinglePassTraversalReadableIterator2 >::iterator_category tag2; | |
return equal_impl(first1, last1, first2, last2, tag1, tag2); | |
} | |
template< class SinglePassTraversalReadableIterator1, | |
class SinglePassTraversalReadableIterator2, | |
class BinaryPredicate > | |
inline bool equal( SinglePassTraversalReadableIterator1 first1, | |
SinglePassTraversalReadableIterator1 last1, | |
SinglePassTraversalReadableIterator2 first2, | |
SinglePassTraversalReadableIterator2 last2, | |
BinaryPredicate pred ) | |
{ | |
BOOST_DEDUCED_TYPENAME std::iterator_traits< SinglePassTraversalReadableIterator1 >::iterator_category tag1; | |
BOOST_DEDUCED_TYPENAME std::iterator_traits< SinglePassTraversalReadableIterator2 >::iterator_category tag2; | |
return equal_impl(first1, last1, first2, last2, pred, tag1, tag2); | |
} | |
} // namespace range_detail | |
namespace range | |
{ | |
/// \brief template function equal | |
/// | |
/// range-based version of the equal std algorithm | |
/// | |
/// \pre SinglePassRange1 is a model of the SinglePassRangeConcept | |
/// \pre SinglePassRange2 is a model of the SinglePassRangeConcept | |
/// \pre BinaryPredicate is a model of the BinaryPredicateConcept | |
template< class SinglePassRange1, class SinglePassRange2 > | |
inline bool equal( const SinglePassRange1& rng1, const SinglePassRange2& rng2 ) | |
{ | |
BOOST_RANGE_CONCEPT_ASSERT(( SinglePassRangeConcept<const SinglePassRange1> )); | |
BOOST_RANGE_CONCEPT_ASSERT(( SinglePassRangeConcept<const SinglePassRange2> )); | |
return ::boost::range_detail::equal( | |
::boost::begin(rng1), ::boost::end(rng1), | |
::boost::begin(rng2), ::boost::end(rng2) ); | |
} | |
/// \overload | |
template< class SinglePassRange1, class SinglePassRange2, class BinaryPredicate > | |
inline bool equal( const SinglePassRange1& rng1, const SinglePassRange2& rng2, | |
BinaryPredicate pred ) | |
{ | |
BOOST_RANGE_CONCEPT_ASSERT(( SinglePassRangeConcept<const SinglePassRange1> )); | |
BOOST_RANGE_CONCEPT_ASSERT(( SinglePassRangeConcept<const SinglePassRange2> )); | |
return ::boost::range_detail::equal( | |
::boost::begin(rng1), ::boost::end(rng1), | |
::boost::begin(rng2), ::boost::end(rng2), | |
pred); | |
} | |
} // namespace range | |
using range::equal; | |
} // namespace boost | |
#endif // include guard |