[Boost-commit] svn:boost r61258 - in trunk: boost/range libs/range/test

Subject: [Boost-commit] svn:boost r61258 - in trunk: boost/range libs/range/test
From: neil_at_[hidden]
Date: 2010-04-13 16:41:12

Author: neilgroves
Date: 2010-04-13 16:41:11 EDT (Tue, 13 Apr 2010)
New Revision: 61258
URL: http://svn.boost.org/trac/boost/changeset/61258

Log:
Boost.Range defect fix for the operator[] of iterator_range. This now reverts to a simpler implementation when the iterator is a pointer.
Added:
   trunk/libs/range/test/pointer_as_iterator.cpp   (contents, props changed)
Text files modified: 
   trunk/boost/range/iterator_range_core.hpp |    45 ++++++++++++++++++++++++++++++++------- 
   trunk/libs/range/test/Jamfile.v2          |     1                                         
   2 files changed, 38 insertions(+), 8 deletions(-)

Modified: trunk/boost/range/iterator_range_core.hpp
==============================================================================
--- trunk/boost/range/iterator_range_core.hpp	(original)
+++ trunk/boost/range/iterator_range_core.hpp	2010-04-13 16:41:11 EDT (Tue, 13 Apr 2010)
@@ -298,14 +298,22 @@
                return m_Begin[at];
            }
 #else
-           BOOST_DEDUCED_TYPENAME boost::detail::operator_brackets_result<iterator, value_type, reference>::type
-           operator[]( difference_type at ) const
-           {
-               BOOST_ASSERT( at >= 0 && at < size() );
-
-               typedef boost::detail::use_operator_brackets_proxy<value_type,reference> use_proxy;
-               return boost::detail::make_operator_brackets_result<iterator>(m_Begin + at, use_proxy());
-           }
+            // Using the operator_brackets_result mechanism properly supports
+            // the corner cases with proxies for references etc. However
+            // the operator_brackets_result implementation does not support
+            // pointers as iterators. Since a pointer can't have the
+            // issues with proxies this implementation uses a simpler
+            // implementation if the iterator is a pointer.
+            BOOST_DEDUCED_TYPENAME boost::mpl::if_<
+                boost::is_pointer<iterator>,
+                reference,
+                BOOST_DEDUCED_TYPENAME boost::detail::operator_brackets_result<iterator, value_type, reference>::type
+            >::type
+            operator[]( difference_type at ) const
+            {
+                BOOST_ASSERT( at >= 0 && at < size() );
+                return get_at(m_Begin, at);
+            }
 #endif
 
            //
@@ -332,6 +340,27 @@
            }
 
         private:
+            template<class Iterator>
+            static BOOST_DEDUCED_TYPENAME boost::enable_if<
+                boost::is_pointer<Iterator>,
+                reference
+                >::type
+            get_at( Iterator it, difference_type at )
+            {
+                return it[at];
+            }
+
+            template<class Iterator>
+            static BOOST_DEDUCED_TYPENAME boost::disable_if<
+                boost::is_pointer<Iterator>,
+                BOOST_DEDUCED_TYPENAME boost::detail::operator_brackets_result<Iterator, value_type, reference>::type
+                >::type
+            get_at( Iterator it, difference_type at )
+            {
+               typedef boost::detail::use_operator_brackets_proxy<value_type,reference> use_proxy;
+               return boost::detail::make_operator_brackets_result<Iterator>(it + at, use_proxy());
+            }
+
             // begin and end iterators
             IteratorT m_Begin;
             IteratorT m_End;

Modified: trunk/libs/range/test/Jamfile.v2
==============================================================================
--- trunk/libs/range/test/Jamfile.v2	(original)
+++ trunk/libs/range/test/Jamfile.v2	2010-04-13 16:41:11 EDT (Tue, 13 Apr 2010)
@@ -133,6 +133,7 @@
 #   	[ range-test mfc : <include>$(VC71_ROOT)/atlmfc/include ]
     [ range-test join ]
         [ range-test partial_workaround ]
+	[ range-test pointer_as_iterator ]
         [ range-test reversible_range ]
         [ range-test std_container ]
         [ range-test string ]

Added: trunk/libs/range/test/pointer_as_iterator.cpp
==============================================================================
--- (empty file)
+++ trunk/libs/range/test/pointer_as_iterator.cpp	2010-04-13 16:41:11 EDT (Tue, 13 Apr 2010)
@@ -0,0 +1,39 @@
+// Boost.Range library
+//
+//  Copyright Neil Groves 2010. 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/iterator_range.hpp>
+#include <boost/range/begin.hpp>
+#include <boost/range/end.hpp>
+#include <boost/array.hpp>
+#include <boost/test/test_tools.hpp>
+#include <boost/test/unit_test.hpp>
+#include <iostream>
+#include <vector>
+
+namespace
+{
+    void test_pointer_as_iterator()
+    {
+        boost::array<int,3> arr;
+        boost::iterator_range<const int*> r(arr.begin(), arr.end());
+        r[0];
+    }
+} // anonymous namespace
+
+boost::unit_test::test_suite*
+init_unit_test_suite(int argc, char* argv[])
+{
+    boost::unit_test::test_suite* test
+        = BOOST_TEST_SUITE( "RangeTestSuite.pointer_as_iterator" );
+
+    test->add(BOOST_TEST_CASE( &test_pointer_as_iterator ));
+
+    return test;
+}