[libstdc++] Checks for lower_bound too strong

[Phil Edwards]

This fixes libstdc++/2054, a long-standing bug in the concept checks.
I mistakenly closed the bug, and nobody else has complained because (almost)
nobody else turns the checks on.  Tested on i686-linux.


2001-12-28  Phil Edwards  <pme@gcc.gnu.org>

	PR libstdc++/2054
	* include/bits/stl_algo.h (lower_bound):  Relax concept checks.
	* testsuite/ext/concept_checks.cc:  New file.


Index: include/bits/stl_algo.h
===================================================================
RCS file: /cvs/gcc/gcc/libstdc++-v3/include/bits/stl_algo.h,v
retrieving revision 1.16
diff -u -3 -p -r1.16 stl_algo.h
--- stl_algo.h	2001/12/28 18:46:54	1.16
+++ stl_algo.h	2001/12/28 21:56:31
@@ -1982,8 +1982,7 @@ __result, __binary_pred, _IterType());
       
       // concept requirements
       __glibcpp_function_requires(_ForwardIteratorConcept<_ForwardIter>)
-      __glibcpp_function_requires(_SameTypeConcept<_Tp, _ValueType>)
-      __glibcpp_function_requires(_BinaryPredicateConcept<_Compare, _Tp, _Tp>)
+      __glibcpp_function_requires(_BinaryPredicateConcept<_Compare, _ValueType, _Tp>)
     
       _DistanceType __len = distance(__first, __last);
       _DistanceType __half;
Index: testsuite/ext/concept_checks.cc
===================================================================
RCS file: concept_checks.cc
diff -N concept_checks.cc
--- /dev/null	Tue May  5 13:32:27 1998
+++ concept_checks.cc	Fri Dec 28 13:56:31 2001
@@ -0,0 +1,76 @@
+// 2001-12-28  Phil Edwards  <pme@gcc.gnu.org>
+//
+// Copyright (C) 2001 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, 59 Temple Place - Suite 330, Boston, MA 02111-1307,
+// USA.
+
+// Concept checking must remain sane.
+
+// { dg-options "-D_GLIBCPP_CONCEPT_CHECKS" }
+
+#include <vector>
+#include <string>
+#include <algorithm>
+#include <testsuite_hooks.h>
+
+using namespace std;
+
+
+// PR libstdc++/2054
+struct indirectCompare
+{
+  indirectCompare(const vector<string>& v) : V(v) {}
+
+  bool operator()( int x,  int y) const
+  {
+       return V[x] < V[y];
+  }
+
+  bool operator()( int x, const string& a) const
+  {
+       return V[x] < a;
+  }
+
+  const vector<string>& V;
+};
+
+void
+test2054( )
+{
+  const int Maxi = 1022;
+
+  vector<string> Words(Maxi);
+  vector<int> Index(Maxi);
+
+  for(size_t i = 0; i < Index.size(); i++)
+     Index[i] = i;
+
+  indirectCompare aComparison(Words);
+
+  sort(Index.begin(), Index.end(), aComparison);
+
+  string SearchTerm;
+
+  lower_bound(Index.begin(), Index.end(), SearchTerm, aComparison);
+}
+
+int main()
+{
+  test2054();
+
+  return 0;
+}