Re: [boost] [range] iterator_range/sub_range test patch

From: Markus Schöpflin (markus.schoepflin_at_[hidden])
Date: 2007-10-12 04:25:45

shunsuke wrote:

> The failures of iterator_range and sub_range.cpp seem to be fixed trivially.
> Wrap string literals with as_literal.
> Am I right?
> Here is a patch.
> http://svn.boost.org/trac/boost/ticket/1302

This patch might fix this particular failure, but I don't think it should 
be applied, as it only masks the real problem.

The failure comes from the fact, that range currently is not able to 
correctly handle char[] types. For example:

str = "hello world"
rr  = make_iterator_range( str.begin(), str.begin() + 5 );
BOOST_CHECK( rr == "hello" );

This fails because rr (length 5) is compared to a char array (length 6), as 
the terminating null character is not correctly handled.

In boost/range/detail/implementation_help.hpp there is code that should 
deal with this, but it is commented out:

template< class T, std::size_t sz >
inline const T* array_end( const T BOOST_RANGE_ARRAY_REF()[sz] )
{
   /*
   typedef BOOST_RANGE_DEDUCED_TYPENAME boost::mpl::if_c<
     is_same<char,T>::value || is_same<wchar_t,T>::value,
     char_or_wchar_t_array_tag, int >::type tag;

   return array_end<T,sz>( boost_range_array, tag() );
   */
   return boost_range_array + sz;
}

If I enable all the deactivated code in this file, all range tests pass for 
me on Tru64/CXX.

Thorsten, is there a reason that prevents you from enabling the deactivated 
code? If you lack the time, do you want me the commit the modified header? 
(See attached patch.)

Markus

Index: implementation_help.hpp
===================================================================
--- implementation_help.hpp	(revision 39918)
+++ implementation_help.hpp	(working copy)
@@ -57,7 +57,6 @@
             return const_cast<Char*>( str_end( s, s ) );
         }
 
-        /*
         template< class T, std::size_t sz >
         inline T* array_end( T BOOST_RANGE_ARRAY_REF()[sz], int )
         {
@@ -81,32 +80,25 @@
         {
             return boost_range_array + sz - 1;
         }
-        */
 
         template< class T, std::size_t sz >
         inline T* array_end( T BOOST_RANGE_ARRAY_REF()[sz] )
         {
-            /*
             typedef BOOST_RANGE_DEDUCED_TYPENAME boost::mpl::if_c< is_same<char,T>::value || is_same<wchar_t,T>::value,
                                                                 char_or_wchar_t_array_tag,
                                                                 int >::type tag;
 
             return array_end<T,sz>( boost_range_array, tag() );
-            */
-            return boost_range_array + sz;
         }
         
         template< class T, std::size_t sz >
         inline const T* array_end( const T BOOST_RANGE_ARRAY_REF()[sz] )
         {
-            /*
             typedef BOOST_RANGE_DEDUCED_TYPENAME boost::mpl::if_c< is_same<char,T>::value || is_same<wchar_t,T>::value,
                                                                 char_or_wchar_t_array_tag,
                                                                 int >::type tag;
         
             return array_end<T,sz>( boost_range_array, tag() );
-            */
-            return boost_range_array + sz;
         }
 
         /////////////////////////////////////////////////////////////////////
@@ -119,7 +111,6 @@
             return str_end( s ) - s;
         }
 
-        /*
         template< class T, std::size_t sz >
         inline std::size_t array_size( T BOOST_RANGE_ARRAY_REF()[sz], int )
         {
@@ -143,31 +134,24 @@
         {
             return sz - 1;
         }
-        */
         
         template< class T, std::size_t sz >
         inline std::size_t array_size( T BOOST_RANGE_ARRAY_REF()[sz] )
         {
-            /*
             typedef BOOST_RANGE_DEDUCED_TYPENAME boost::mpl::if_c< is_same<const char,T>::value || is_same<const wchar_t,T>::value ||
                                                                    is_same<char,T>::value       || is_same<wchar_t,T>::value,
                                                                 char_or_wchar_t_array_tag,
                                                                 int >::type tag;
             return array_size<T,sz>( boost_range_array, tag() );
-            */
-            return sz;
         }
 
         template< class T, std::size_t sz >
         inline std::size_t array_size( const T BOOST_RANGE_ARRAY_REF()[sz] )
         {
-            /*
             typedef BOOST_RANGE_DEDUCED_TYPENAME boost::mpl::if_c< is_same<char,T>::value || is_same<wchar_t,T>::value,
                                                                 char_or_wchar_t_array_tag,
                                                                 int >::type tag;
             return array_size<T,sz>( boost_range_array, tag() );
-            */
-            return sz;
         }
 
     } // namespace 'range_detail'