Boost.RangeEx merged into Boost.Range

[SVN r60897]

include/boost/range/algorithm/equal.hpp

@@ -0,0 +1,182 @@
+// 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);
+        }
+ 
+    }
+
+    /// \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::function_requires< SinglePassRangeConcept<SinglePassRange1> >();
+        boost::function_requires< SinglePassRangeConcept<SinglePassRange2> >();
+
+        return 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::function_requires< SinglePassRangeConcept<SinglePassRange1> >();
+        boost::function_requires< SinglePassRangeConcept<SinglePassRange2> >();
+
+        return range_detail::equal(
+            boost::begin(rng1), boost::end(rng1),
+            boost::begin(rng2), boost::end(rng2),
+            pred);
+    }
+}
+
+#endif // include guard