[Patch] ADL issues: string

[Paolo Carlini <pcarlini at suse dot de>]

Hi,

the below (versus v7, but clearly a candidate for mainline in a few
days), is what I need to solve the issues affecting basic_string. A
separate one will deal with vector, probably more complex...

Anyway, besides avoiding operator+ on __normal_iterator, trivial, I also
need to add an overload of operator- for left and right of the same type
(see also the testcase), besides the one for unequal types already
present (useful for mixes of iterator and const_iterator). The issue
dates back to the implementation of DR 179.

Can you see any problem with this? Otherwise I will commit it tomorrow
and go ahead with vector.

Tested x86-linux.

Paolo.

///////////////////

2005-12-01  Paolo Carlini  <pcarlini@suse.de>

	* include/bits/basic_string.h (insert(iterator, _CharT),
	erase(iterator), erase(iterator, iterator)): Avoid troubles
	with ADL, user defined operators and __normal_iterator.
	* include/bits/stl_iterator.h (operator-(const __normal_iterator
	<_Iterator, _Container>&, const __normal_iterator<_Iterator,
	_Container>&)): Add overload for left and right iterators of
	the same type.
	* include/debug/safe_iterator.h (operator-(const _Safe_iterator
	<_Iterator, _Sequence>&, const _Safe_iterator<_Iterator,
	_Sequence>&)): Likewise.
	* testsuite/21_strings/basic_string/3.cc: New.

Index: include/bits/basic_string.h
===================================================================
--- include/bits/basic_string.h	(revision 107718)
+++ include/bits/basic_string.h	(working copy)
@@ -890,7 +890,7 @@
 	const size_type __pos = __p - _M_ibegin();
 	_M_replace_aux(__pos, size_type(0), size_type(1), __c);
 	this->_M_set_leaked();
-	return _M_ibegin() + __pos;
+	return iterator(this->_M_data() + __pos);
       }
 
       /**
@@ -931,7 +931,7 @@
 	const size_type __pos = __position - _M_ibegin();
 	this->_M_erase(__pos, size_type(1));
 	this->_M_set_leaked();
-	return _M_ibegin() + __pos;
+	return iterator(this->_M_data() + __pos);
       }
 
       /**
@@ -951,7 +951,7 @@
         const size_type __pos = __first - _M_ibegin();
 	this->_M_erase(__pos, __last - __first);
 	this->_M_set_leaked();
-	return _M_ibegin() + __pos;
+	return iterator(this->_M_data() + __pos);
       }
 
       /**
Index: include/bits/stl_iterator.h
===================================================================
--- include/bits/stl_iterator.h	(revision 106945)
+++ include/bits/stl_iterator.h	(working copy)
@@ -808,6 +808,12 @@
     { return __lhs.base() - __rhs.base(); }
 
   template<typename _Iterator, typename _Container>
+    inline typename __normal_iterator<_Iterator, _Container>::difference_type
+    operator-(const __normal_iterator<_Iterator, _Container>& __lhs,
+	      const __normal_iterator<_Iterator, _Container>& __rhs)
+    { return __lhs.base() - __rhs.base(); }
+
+  template<typename _Iterator, typename _Container>
     inline __normal_iterator<_Iterator, _Container>
     operator+(typename __normal_iterator<_Iterator, _Container>::difference_type
 	      __n, const __normal_iterator<_Iterator, _Container>& __i)
Index: include/debug/safe_iterator.h
===================================================================
--- include/debug/safe_iterator.h	(revision 106945)
+++ include/debug/safe_iterator.h	(working copy)
@@ -608,6 +608,22 @@
     }
 
   template<typename _Iterator, typename _Sequence>
+    inline typename _Safe_iterator<_Iterator, _Sequence>::difference_type
+    operator-(const _Safe_iterator<_Iterator, _Sequence>& __lhs,
+	      const _Safe_iterator<_Iterator, _Sequence>& __rhs)
+    {
+      _GLIBCXX_DEBUG_VERIFY(! __lhs._M_singular() && ! __rhs._M_singular(),
+			    _M_message(__msg_distance_bad)
+			    ._M_iterator(__lhs, "lhs")
+			    ._M_iterator(__rhs, "rhs"));
+      _GLIBCXX_DEBUG_VERIFY(__lhs._M_can_compare(__rhs),
+			    _M_message(__msg_distance_different)
+			    ._M_iterator(__lhs, "lhs")
+			    ._M_iterator(__rhs, "rhs"));
+      return __lhs.base() - __rhs.base();
+    }
+
+  template<typename _Iterator, typename _Sequence>
     inline _Safe_iterator<_Iterator, _Sequence>
     operator+(typename _Safe_iterator<_Iterator,_Sequence>::difference_type __n,
 	      const _Safe_iterator<_Iterator, _Sequence>& __i)
Index: testsuite/21_strings/basic_string/3.cc
===================================================================
--- testsuite/21_strings/basic_string/3.cc	(revision 0)
+++ testsuite/21_strings/basic_string/3.cc	(revision 0)
@@ -0,0 +1,46 @@
+// 2005-12-01  Paolo Carlini  <pcarlini@suse.de>
+
+// Copyright (C) 2005 Free Software Foundation, Inc.
+//
+// This file is part of the GNU ISO C++ Library.  This library is free
+// software; you can redistribute it and/or modify it under the
+// terms of the GNU General Public License as published by the
+// Free Software Foundation; either version 2, or (at your option)
+// any later version.
+
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License along
+// with this library; see the file COPYING.  If not, write to the Free
+// Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301,
+// USA.
+
+// { dg-do compile }
+
+#include <string>
+
+namespace N
+{
+  struct X { };
+
+  template<typename T>
+    X operator+(T, std::size_t)
+    { return X(); }
+
+  template<typename T>
+    X operator-(T, T)
+    { return X(); }
+}
+
+int main()
+{ 
+  std::basic_string<N::X> s(5, N::X());
+
+  s.erase(s.begin());
+  s.erase(s.begin(), s.end());
+  s.insert(s.begin(), N::X());
+  s.replace(s.begin(), s.end(), s.begin(), s.end());
+}