re PR libstdc++/25306 (fill_n, generate_n assume Size is modifiable)

2010-05-21  Paolo Carlini  <paolo.carlini@oracle.com>

	PR libstdc++/25306
	* include/bits/stl_algobase.h (fill_n): Use a properly typed __niter
	initialized to __n.
	* include/bits/stl_algo.h (generate_n): Likewise.
	* testsuite/25_algorithms/fill_n/25306.cc: New.
	* testsuite/25_algorithms/generate_n/25306.cc: Likewise.

From-SVN: r159677

5 files changed, 75 insertions, 3 deletions

diff --git a/libstdc++-v3/ChangeLog b/libstdc++-v3/ChangeLog
index 1eb3a31..82d13da 100644
--- a/libstdc++-v3/ChangeLog
+++ b/libstdc++-v3/ChangeLog
@@ -1,3 +1,12 @@
+2010-05-21  Paolo Carlini  <paolo.carlini@oracle.com>
+
+	PR libstdc++/25306
+	* include/bits/stl_algobase.h (fill_n): Use a properly typed __niter
+	initialized to __n.
+	* include/bits/stl_algo.h (generate_n): Likewise.
+	* testsuite/25_algorithms/fill_n/25306.cc: New.
+	* testsuite/25_algorithms/generate_n/25306.cc: Likewise.
+
 2010-05-21  Joseph Myers  <joseph@codesourcery.com>
 
 	* acinclude.m4 (GLIBCXX_ENABLE_CLOCALE): Use GNU locale model for
diff --git a/libstdc++-v3/include/bits/stl_algo.h b/libstdc++-v3/include/bits/stl_algo.h
index 5b4991e..fe2edb9 100644
--- a/libstdc++-v3/include/bits/stl_algo.h
+++ b/libstdc++-v3/include/bits/stl_algo.h
@@ -4844,7 +4844,8 @@ _GLIBCXX_BEGIN_NESTED_NAMESPACE(std, _GLIBCXX_STD_P)
             // "the type returned by a _Generator"
             __typeof__(__gen())>)
 
-      for (; __n > 0; --__n, ++__first)
+      for (__decltype(__n + 0) __niter = __n;
+	   __niter > 0; --__niter, ++__first)
 	*__first = __gen();
       return __first;
     }
diff --git a/libstdc++-v3/include/bits/stl_algobase.h b/libstdc++-v3/include/bits/stl_algobase.h
index e925404..0489c41 100644
--- a/libstdc++-v3/include/bits/stl_algobase.h
+++ b/libstdc++-v3/include/bits/stl_algobase.h
@@ -748,7 +748,8 @@ _GLIBCXX_BEGIN_NAMESPACE(std)
     __gnu_cxx::__enable_if<!__is_scalar<_Tp>::__value, _OutputIterator>::__type
     __fill_n_a(_OutputIterator __first, _Size __n, const _Tp& __value)
     {
-      for (; __n > 0; --__n, ++__first)
+      for (__decltype(__n + 0) __niter = __n;
+	   __niter > 0; --__niter, ++__first)
 	*__first = __value;
       return __first;
     }
@@ -759,7 +760,8 @@ _GLIBCXX_BEGIN_NAMESPACE(std)
     __fill_n_a(_OutputIterator __first, _Size __n, const _Tp& __value)
     {
       const _Tp __tmp = __value;
-      for (; __n > 0; --__n, ++__first)
+      for (__decltype(__n + 0) __niter = __n;
+	   __niter > 0; --__niter, ++__first)
 	*__first = __tmp;
       return __first;
     }
diff --git a/libstdc++-v3/testsuite/25_algorithms/fill_n/25306.cc b/libstdc++-v3/testsuite/25_algorithms/fill_n/25306.cc
new file mode 100644
index 0000000..37ccd7c
--- /dev/null
+++ b/libstdc++-v3/testsuite/25_algorithms/fill_n/25306.cc
@@ -0,0 +1,30 @@
+// { dg-do compile }
+
+// Copyright (C) 2010 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 3, 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 COPYING3.  If not see
+// <http://www.gnu.org/licenses/>.
+
+#include <algorithm>
+
+struct Size
+{
+  operator int() { return 0; }
+private:
+  void operator=(Size&);
+};
+
+// libstdc++/25306
+template int* std::fill_n(int*, Size, const int&);
diff --git a/libstdc++-v3/testsuite/25_algorithms/generate_n/25306.cc b/libstdc++-v3/testsuite/25_algorithms/generate_n/25306.cc
new file mode 100644
index 0000000..f73ff3d
--- /dev/null
+++ b/libstdc++-v3/testsuite/25_algorithms/generate_n/25306.cc
@@ -0,0 +1,30 @@
+// { dg-do compile }
+
+// Copyright (C) 2010 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 3, 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 COPYING3.  If not see
+// <http://www.gnu.org/licenses/>.
+
+#include <algorithm>
+
+struct Size
+{
+  operator int() { return 0; }
+private:
+  void operator=(Size&);
+};
+
+// libstdc++/25306
+template int* std::generate_n(int*, Size, int (*)());