re PR libstdc++/37547 ([c++0x] minmax with initializer_list gives incorrect results)

2008-09-17  Paolo Carlini  <paolo.carlini@oracle.com>

	PR libstdc++/37547
	* include/bits/stl_algo.h (min(initializer_list<>),
	min(initializer_list<>, Compare), max(initializer_list<>),
	max(initializer_list<>, Compare), minmax(initializer_list<>),
	minmax(initializer_list<>, Compare)): Fix return type.
	* include/bits/algorithmfwd.h: Adjust.
	* testsuite/25_algorithms/headers/algorithm/synopsis.cc: Likewise.
	* testsuite/25_algorithms/max/requirements/explicit_instantiation/3.cc:
        Likewise.
        * testsuite/25_algorithms/max/requirements/explicit_instantiation/
        pod2.cc: Likewise.
	* testsuite/25_algorithms/min/requirements/explicit_instantiation/3.cc:
        Likewise.
        * testsuite/25_algorithms/min/requirements/explicit_instantiation/
        pod2.cc: Likewise.
	* testsuite/25_algorithms/minmax/requirements/explicit_instantiation/
	3.cc: Likewise.
        * testsuite/25_algorithms/minmax/requirements/explicit_instantiation/
        pod2.cc: Likewise.
	* testsuite/25_algorithms/max/37547.cc: New.
	* testsuite/25_algorithms/min/37547.cc: Likewise.
	* testsuite/25_algorithms/minmax/37547.cc: Likewise.

From-SVN: r140435

13 files changed, 179 insertions, 36 deletions

diff --git a/libstdc++-v3/ChangeLog b/libstdc++-v3/ChangeLog
index 3c2d291..0d9e413 100644
--- a/libstdc++-v3/ChangeLog
+++ b/libstdc++-v3/ChangeLog
@@ -1,3 +1,28 @@
+2008-09-17  Paolo Carlini  <paolo.carlini@oracle.com>
+
+	PR libstdc++/37547
+	* include/bits/stl_algo.h (min(initializer_list<>),
+	min(initializer_list<>, Compare), max(initializer_list<>),
+	max(initializer_list<>, Compare), minmax(initializer_list<>),
+	minmax(initializer_list<>, Compare)): Fix return type.
+	* include/bits/algorithmfwd.h: Adjust.
+	* testsuite/25_algorithms/headers/algorithm/synopsis.cc: Likewise.
+	* testsuite/25_algorithms/max/requirements/explicit_instantiation/3.cc:
+        Likewise.
+        * testsuite/25_algorithms/max/requirements/explicit_instantiation/
+        pod2.cc: Likewise.
+	* testsuite/25_algorithms/min/requirements/explicit_instantiation/3.cc:
+        Likewise.
+        * testsuite/25_algorithms/min/requirements/explicit_instantiation/
+        pod2.cc: Likewise.
+	* testsuite/25_algorithms/minmax/requirements/explicit_instantiation/
+	3.cc: Likewise.
+        * testsuite/25_algorithms/minmax/requirements/explicit_instantiation/
+        pod2.cc: Likewise.
+	* testsuite/25_algorithms/max/37547.cc: New.
+	* testsuite/25_algorithms/min/37547.cc: Likewise.
+	* testsuite/25_algorithms/minmax/37547.cc: Likewise.
+
 2008-09-16  Chris Fairles  <chris.fairles@gmail.com>
 
         * testsuite/25_algorithms/min/requirements/explicit_instantiation/3.cc:
diff --git a/libstdc++-v3/include/bits/algorithmfwd.h b/libstdc++-v3/include/bits/algorithmfwd.h
index 95ff72b..0e2e2c0 100644
--- a/libstdc++-v3/include/bits/algorithmfwd.h
+++ b/libstdc++-v3/include/bits/algorithmfwd.h
@@ -319,27 +319,27 @@ _GLIBCXX_BEGIN_NAMESPACE(std)
     minmax_element(_FIter, _FIter, _Compare);
 
   template<typename _Tp>
-    const _Tp&
+    _Tp
     min(initializer_list<_Tp>);
 
   template<typename _Tp, typename _Compare>
-    const _Tp&
+    _Tp
     min(initializer_list<_Tp>, _Compare);
 
   template<typename _Tp>
-    const _Tp&
+    _Tp
     max(initializer_list<_Tp>);
 
   template<typename _Tp, typename _Compare>
-    const _Tp&
+    _Tp
     max(initializer_list<_Tp>, _Compare);
 
   template<typename _Tp>
-    pair<const _Tp&, const _Tp&>
+    pair<_Tp, _Tp>
     minmax(initializer_list<_Tp>);
 
   template<typename _Tp, typename _Compare>
-    pair<const _Tp&, const _Tp&>
+    pair<_Tp, _Tp>
     minmax(initializer_list<_Tp>, _Compare);
 #endif
 
diff --git a/libstdc++-v3/include/bits/stl_algo.h b/libstdc++-v3/include/bits/stl_algo.h
index 42ada99..373881c 100644
--- a/libstdc++-v3/include/bits/stl_algo.h
+++ b/libstdc++-v3/include/bits/stl_algo.h
@@ -4094,38 +4094,38 @@ _GLIBCXX_BEGIN_NAMESPACE(std)
       return std::make_pair(__min, __max);
     }
 
-  // N2722.
+  // N2722 + fixes.
   template<typename _Tp>
-    inline const _Tp&
+    inline _Tp
     min(initializer_list<_Tp> __l)
     { return *std::min_element(__l.begin(), __l.end()); }
 
   template<typename _Tp, typename _Compare>
-    inline const _Tp&
+    inline _Tp
     min(initializer_list<_Tp> __l, _Compare __comp)
     { return *std::min_element(__l.begin(), __l.end(), __comp); }
 
   template<typename _Tp>
-    inline const _Tp&
+    inline _Tp
     max(initializer_list<_Tp> __l)
     { return *std::max_element(__l.begin(), __l.end()); }
 
   template<typename _Tp, typename _Compare>
-    inline const _Tp&
+    inline _Tp
     max(initializer_list<_Tp> __l, _Compare __comp)
     { return *std::max_element(__l.begin(), __l.end(), __comp); }
 
   template<typename _Tp>
-    inline pair<const _Tp&, const _Tp&>
+    inline pair<_Tp, _Tp>
     minmax(initializer_list<_Tp> __l)
     {
       pair<const _Tp*, const _Tp*> __p =
 	std::minmax_element(__l.begin(), __l.end());
-      return std::make_pair(*__p.first, *__p.second);
+      return std::pair<_Tp, _Tp>(*__p.first, *__p.second);
     }
 
   template<typename _Tp, typename _Compare>
-    inline pair<const _Tp&, const _Tp&>
+    inline pair<_Tp, _Tp>
     minmax(initializer_list<_Tp> __l, _Compare __comp)
     {
       pair<const _Tp*, const _Tp*> __p =
diff --git a/libstdc++-v3/testsuite/25_algorithms/headers/algorithm/synopsis.cc b/libstdc++-v3/testsuite/25_algorithms/headers/algorithm/synopsis.cc
index 3bc8eb2..aa4496b 100644
--- a/libstdc++-v3/testsuite/25_algorithms/headers/algorithm/synopsis.cc
+++ b/libstdc++-v3/testsuite/25_algorithms/headers/algorithm/synopsis.cc
@@ -533,27 +533,27 @@ namespace std
     minmax_element(_FIter, _FIter, _Compare);
 
   template<typename _Tp>
-    const _Tp&
+    _Tp
     min(initializer_list<_Tp>);
 
   template<typename _Tp, typename _Compare>
-    const _Tp&
+    _Tp
     min(initializer_list<_Tp>, _Compare);
 
   template<typename _Tp>
-    const _Tp&
+    _Tp
     max(initializer_list<_Tp>);
 
   template<typename _Tp, typename _Compare>
-    const _Tp&
+    _Tp
     max(initializer_list<_Tp>, _Compare);
 
   template<typename _Tp>
-    pair<const _Tp&, const _Tp&>
+    pair<_Tp, _Tp>
     minmax(initializer_list<_Tp>);
 
   template<typename _Tp, typename _Compare>
-    pair<const _Tp&, const _Tp&>
+    pair<_Tp, _Tp>
     minmax(initializer_list<_Tp>, _Compare);
 #endif
 
diff --git a/libstdc++-v3/testsuite/25_algorithms/max/37547.cc b/libstdc++-v3/testsuite/25_algorithms/max/37547.cc
new file mode 100644
index 0000000..233804c
--- /dev/null
+++ b/libstdc++-v3/testsuite/25_algorithms/max/37547.cc
@@ -0,0 +1,40 @@
+// { dg-options "-std=gnu++0x" }
+
+// Copyright (C) 2008 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.
+
+#include <algorithm>
+#include <vector>
+#include <testsuite_hooks.h>
+
+// libstdc++/37547
+int test01()
+{
+  bool test __attribute__((unused)) = true;
+
+  std::vector<int> v{1,2,3,4,5};
+
+  auto p = std::max({v});
+  VERIFY ( p == v );
+}
+
+int main()
+{
+  test01();
+  return 0;
+}
diff --git a/libstdc++-v3/testsuite/25_algorithms/max/requirements/explicit_instantiation/3.cc b/libstdc++-v3/testsuite/25_algorithms/max/requirements/explicit_instantiation/3.cc
index e4ac6cb..1f242c9 100644
--- a/libstdc++-v3/testsuite/25_algorithms/max/requirements/explicit_instantiation/3.cc
+++ b/libstdc++-v3/testsuite/25_algorithms/max/requirements/explicit_instantiation/3.cc
@@ -42,6 +42,6 @@ namespace std
   typedef value_type* 		iterator_type;
   typedef std::less<value_type> compare_type;
 
-  template const value_type&  max(initializer_list<value_type>);
-  template const value_type&  max(initializer_list<value_type>, compare_type);
+  template value_type max(initializer_list<value_type>);
+  template value_type max(initializer_list<value_type>, compare_type);
 } 
diff --git a/libstdc++-v3/testsuite/25_algorithms/max/requirements/explicit_instantiation/pod2.cc b/libstdc++-v3/testsuite/25_algorithms/max/requirements/explicit_instantiation/pod2.cc
index 55f2eae..0e623e2 100644
--- a/libstdc++-v3/testsuite/25_algorithms/max/requirements/explicit_instantiation/pod2.cc
+++ b/libstdc++-v3/testsuite/25_algorithms/max/requirements/explicit_instantiation/pod2.cc
@@ -42,6 +42,6 @@ namespace std
   typedef value_type* 		iterator_type;
   typedef std::less<value_type> compare_type;
 
-  template const value_type&  max(initializer_list<value_type>);
-  template const value_type&  max(initializer_list<value_type>, compare_type);
+  template value_type max(initializer_list<value_type>);
+  template value_type max(initializer_list<value_type>, compare_type);
 } 
diff --git a/libstdc++-v3/testsuite/25_algorithms/min/37547.cc b/libstdc++-v3/testsuite/25_algorithms/min/37547.cc
new file mode 100644
index 0000000..5d0ffd4
--- /dev/null
+++ b/libstdc++-v3/testsuite/25_algorithms/min/37547.cc
@@ -0,0 +1,40 @@
+// { dg-options "-std=gnu++0x" }
+
+// Copyright (C) 2008 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.
+
+#include <algorithm>
+#include <vector>
+#include <testsuite_hooks.h>
+
+// libstdc++/37547
+int test01()
+{
+  bool test __attribute__((unused)) = true;
+
+  std::vector<int> v{1,2,3,4,5};
+
+  auto p = std::min({v});
+  VERIFY ( p == v );
+}
+
+int main()
+{
+  test01();
+  return 0;
+}
diff --git a/libstdc++-v3/testsuite/25_algorithms/min/requirements/explicit_instantiation/3.cc b/libstdc++-v3/testsuite/25_algorithms/min/requirements/explicit_instantiation/3.cc
index 1d6e7ae..7faea37 100644
--- a/libstdc++-v3/testsuite/25_algorithms/min/requirements/explicit_instantiation/3.cc
+++ b/libstdc++-v3/testsuite/25_algorithms/min/requirements/explicit_instantiation/3.cc
@@ -42,6 +42,6 @@ namespace std
   typedef value_type* 		iterator_type;
   typedef std::less<value_type> compare_type;
 
-  template const value_type&  min(initializer_list<value_type>);
-  template const value_type&  min(initializer_list<value_type>, compare_type);
+  template value_type min(initializer_list<value_type>);
+  template value_type min(initializer_list<value_type>, compare_type);
 } 
diff --git a/libstdc++-v3/testsuite/25_algorithms/min/requirements/explicit_instantiation/pod2.cc b/libstdc++-v3/testsuite/25_algorithms/min/requirements/explicit_instantiation/pod2.cc
index 98c8413..4800c1b 100644
--- a/libstdc++-v3/testsuite/25_algorithms/min/requirements/explicit_instantiation/pod2.cc
+++ b/libstdc++-v3/testsuite/25_algorithms/min/requirements/explicit_instantiation/pod2.cc
@@ -42,6 +42,6 @@ namespace std
   typedef value_type* 		iterator_type;
   typedef std::less<value_type> compare_type;
 
-  template const value_type&  min(initializer_list<value_type>);
-  template const value_type&  min(initializer_list<value_type>, compare_type);
+  template value_type min(initializer_list<value_type>);
+  template value_type min(initializer_list<value_type>, compare_type);
 } 
diff --git a/libstdc++-v3/testsuite/25_algorithms/minmax/37547.cc b/libstdc++-v3/testsuite/25_algorithms/minmax/37547.cc
new file mode 100644
index 0000000..21de390
--- /dev/null
+++ b/libstdc++-v3/testsuite/25_algorithms/minmax/37547.cc
@@ -0,0 +1,40 @@
+// { dg-options "-std=gnu++0x" }
+
+// Copyright (C) 2008 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.
+
+#include <algorithm>
+#include <vector>
+#include <testsuite_hooks.h>
+
+// libstdc++/37547
+int test01()
+{
+  bool test __attribute__((unused)) = true;
+
+  std::vector<int> v{1,2,3,4,5};
+
+  auto p = std::minmax({v});
+  VERIFY ( p.first == v );
+}
+
+int main()
+{
+  test01();
+  return 0;
+}
diff --git a/libstdc++-v3/testsuite/25_algorithms/minmax/requirements/explicit_instantiation/3.cc b/libstdc++-v3/testsuite/25_algorithms/minmax/requirements/explicit_instantiation/3.cc
index 71fab66..a6506ca 100644
--- a/libstdc++-v3/testsuite/25_algorithms/minmax/requirements/explicit_instantiation/3.cc
+++ b/libstdc++-v3/testsuite/25_algorithms/minmax/requirements/explicit_instantiation/3.cc
@@ -42,8 +42,7 @@ namespace std
   typedef value_type* 		iterator_type;
   typedef std::less<value_type> compare_type;
 
-  template pair<const value_type&, const value_type&>
-    minmax(initializer_list<value_type>);
-  template pair<const value_type&, const value_type&>
-    minmax(initializer_list<value_type>, compare_type);
+  template pair<value_type, value_type> minmax(initializer_list<value_type>);
+  template pair<value_type, value_type> minmax(initializer_list<value_type>,
+					       compare_type);
 }
diff --git a/libstdc++-v3/testsuite/25_algorithms/minmax/requirements/explicit_instantiation/pod2.cc b/libstdc++-v3/testsuite/25_algorithms/minmax/requirements/explicit_instantiation/pod2.cc
index d528593..b31d38d 100644
--- a/libstdc++-v3/testsuite/25_algorithms/minmax/requirements/explicit_instantiation/pod2.cc
+++ b/libstdc++-v3/testsuite/25_algorithms/minmax/requirements/explicit_instantiation/pod2.cc
@@ -42,8 +42,7 @@ namespace std
   typedef value_type* 		iterator_type;
   typedef std::less<value_type> compare_type;
 
-  template pair<const value_type&, const value_type&>
-    minmax(initializer_list<value_type>);
-  template pair<const value_type&, const value_type&>
-    minmax(initializer_list<value_type>, compare_type);
+  template pair<value_type, value_type> minmax(initializer_list<value_type>);
+  template pair<value_type, value_type> minmax(initializer_list<value_type>,
+					       compare_type);
 }