re PR libstdc++/60271 ([DR2369] [C++1y] std::max(initializer_list<T>) cannot use std::max_element)

2014-12-22  Ville Voutilainen  <ville.voutilainen@gmail.com>

	PR libstdc++/60271
	C++14 constexpr min, max, minmax, min_element, max_element
	and minmax_element. Also constexpr for 20.9.5-20.9.9,
	aka various library functors.
	* include/bits/c++config: Add _GLIBCXX14_CONSTEXPR.
	* include/bits/algorithmfwd.h (min, max, minmax, min_element,
	max_element): Use it.
	* include/bits/predefined_ops.h (_Iter_less_iter, __iter_less_iter,
	_Iter_comp_iter, __iter_comp_iter): Likewise.
	* include/bits/stl_algo.h (minmax, __minmax_element, minmax_element,
	min, max, __min_element, min_element, __max_element, max_element)
	Likewise.
	* include/bits/stl_algobase.h (min, max): Likewise.
	* include/bits/stl_function.h (plus, minus, multiplies, divides,
	modulus, negate, equal_to, not_equal_to, greater, less, greater_equal,
	less_equal, logical_and, logical_or, logical_not, bit_and, bit_or,
	bit_xor, bit_not, unary_negate, not1, binary_negate, not2): Likewise.
	* testsuite/20_util/function_objects/constexpr.cc: New.
	* testsuite/25_algorithms/max/constexpr.cc: Likewise.
	* testsuite/25_algorithms/max_element/constexpr.cc: Likewise.
	* testsuite/25_algorithms/min/constexpr.cc: Likewise.
	* testsuite/25_algorithms/min_element/constexpr.cc: Likewise.
	* testsuite/25_algorithms/minmax/constexpr.cc: Likewise.
	* testsuite/25_algorithms/minmax_element/constexpr.cc: Likewise.
	* testsuite/ext/profile/mutex_extensions_neg.cc: Adjust dg-error.

From-SVN: r219015

libstdc++-v3/ChangeLog

+2014-12-22  Ville Voutilainen  <ville.voutilainen@gmail.com>
+
+	PR libstdc++/60271
+	C++14 constexpr min, max, minmax, min_element, max_element
+	and minmax_element. Also constexpr for 20.9.5-20.9.9,
+	aka various library functors.
+	* include/bits/c++config: Add _GLIBCXX14_CONSTEXPR.
+	* include/bits/algorithmfwd.h (min, max, minmax, min_element,
+	max_element): Use it.
+	* include/bits/predefined_ops.h (_Iter_less_iter, __iter_less_iter,
+	_Iter_comp_iter, __iter_comp_iter): Likewise.
+	* include/bits/stl_algo.h (minmax, __minmax_element, minmax_element,
+	min, max, __min_element, min_element, __max_element, max_element)
+	Likewise.
+	* include/bits/stl_algobase.h (min, max): Likewise.
+	* include/bits/stl_function.h (plus, minus, multiplies, divides,
+	modulus, negate, equal_to, not_equal_to, greater, less, greater_equal,
+	less_equal, logical_and, logical_or, logical_not, bit_and, bit_or,
+	bit_xor, bit_not, unary_negate, not1, binary_negate, not2): Likewise.
+	* testsuite/20_util/function_objects/constexpr.cc: New.
+	* testsuite/25_algorithms/max/constexpr.cc: Likewise.
+	* testsuite/25_algorithms/max_element/constexpr.cc: Likewise.
+	* testsuite/25_algorithms/min/constexpr.cc: Likewise.
+	* testsuite/25_algorithms/min_element/constexpr.cc: Likewise.
+	* testsuite/25_algorithms/minmax/constexpr.cc: Likewise.
+	* testsuite/25_algorithms/minmax_element/constexpr.cc: Likewise.
+	* testsuite/ext/profile/mutex_extensions_neg.cc: Adjust dg-error.
+
 2014-12-22  Jonathan Wakely  <jwakely@redhat.com>
 
 	* doc/xml/manual/status_cxx2011.xml: Update.

libstdc++-v3/include/bits/algorithmfwd.h

@@ -352,10 +352,12 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
     make_heap(_RAIter, _RAIter, _Compare);
 
   template<typename _Tp> 
+    _GLIBCXX14_CONSTEXPR
     const _Tp& 
     max(const _Tp&, const _Tp&);
 
   template<typename _Tp, typename _Compare>
+    _GLIBCXX14_CONSTEXPR
     const _Tp& 
     max(const _Tp&, const _Tp&, _Compare);
 
@@ -363,10 +365,12 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
   // merge
 
   template<typename _Tp> 
+    _GLIBCXX14_CONSTEXPR
     const _Tp& 
     min(const _Tp&, const _Tp&);
 
   template<typename _Tp, typename _Compare>
+    _GLIBCXX14_CONSTEXPR
     const _Tp& 
     min(const _Tp&, const _Tp&, _Compare);
 
@@ -374,42 +378,52 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
 
 #if __cplusplus >= 201103L
   template<typename _Tp>
+    _GLIBCXX14_CONSTEXPR
     pair<const _Tp&, const _Tp&> 
     minmax(const _Tp&, const _Tp&);
 
   template<typename _Tp, typename _Compare>
+    _GLIBCXX14_CONSTEXPR
     pair<const _Tp&, const _Tp&>
     minmax(const _Tp&, const _Tp&, _Compare);
 
   template<typename _FIter>
+    _GLIBCXX14_CONSTEXPR
     pair<_FIter, _FIter>
     minmax_element(_FIter, _FIter);
 
   template<typename _FIter, typename _Compare>
+    _GLIBCXX14_CONSTEXPR
     pair<_FIter, _FIter>
     minmax_element(_FIter, _FIter, _Compare);
 
   template<typename _Tp>
+    _GLIBCXX14_CONSTEXPR
     _Tp
     min(initializer_list<_Tp>);
 
   template<typename _Tp, typename _Compare>
+    _GLIBCXX14_CONSTEXPR
     _Tp
     min(initializer_list<_Tp>, _Compare);
 
   template<typename _Tp>
+    _GLIBCXX14_CONSTEXPR
     _Tp
     max(initializer_list<_Tp>);
 
   template<typename _Tp, typename _Compare>
+    _GLIBCXX14_CONSTEXPR
     _Tp
     max(initializer_list<_Tp>, _Compare);
 
   template<typename _Tp>
+    _GLIBCXX14_CONSTEXPR
     pair<_Tp, _Tp>
     minmax(initializer_list<_Tp>);
 
   template<typename _Tp, typename _Compare>
+    _GLIBCXX14_CONSTEXPR
     pair<_Tp, _Tp>
     minmax(initializer_list<_Tp>, _Compare);
 #endif
@@ -655,10 +669,12 @@ _GLIBCXX_BEGIN_NAMESPACE_ALGO
     lexicographical_compare(_IIter1, _IIter1, _IIter2, _IIter2, _Compare);
 
   template<typename _FIter>
+    _GLIBCXX14_CONSTEXPR
     _FIter 
     max_element(_FIter, _FIter);
 
   template<typename _FIter, typename _Compare>
+    _GLIBCXX14_CONSTEXPR
     _FIter 
     max_element(_FIter, _FIter, _Compare);
 
@@ -672,10 +688,12 @@ _GLIBCXX_BEGIN_NAMESPACE_ALGO
     merge(_IIter1, _IIter1, _IIter2, _IIter2, _OIter, _Compare);
 
   template<typename _FIter>
+    _GLIBCXX14_CONSTEXPR
     _FIter 
     min_element(_FIter, _FIter);
 
   template<typename _FIter, typename _Compare>
+    _GLIBCXX14_CONSTEXPR
     _FIter 
     min_element(_FIter, _FIter, _Compare);
 

libstdc++-v3/include/bits/c++config

@@ -103,6 +103,14 @@
 # endif
 #endif
 
+#ifndef _GLIBCXX14_CONSTEXPR
+# if __cplusplus >= 201402L
+#  define _GLIBCXX14_CONSTEXPR constexpr
+# else
+#  define _GLIBCXX14_CONSTEXPR
+# endif
+#endif
+
 // Macro for noexcept, to support in mixed 03/0x mode.
 #ifndef _GLIBCXX_NOEXCEPT
 # if __cplusplus >= 201103L

libstdc++-v3/include/bits/predefined_ops.h

@@ -37,11 +37,12 @@ namespace __ops
   struct _Iter_less_iter
   {
     template<typename _Iterator1, typename _Iterator2>
+      _GLIBCXX14_CONSTEXPR
       bool
       operator()(_Iterator1 __it1, _Iterator2 __it2) const
       { return *__it1 < *__it2; }
   };
-
+  _GLIBCXX14_CONSTEXPR
   inline _Iter_less_iter
   __iter_less_iter()
   { return _Iter_less_iter(); }
@@ -110,18 +111,20 @@ namespace __ops
     struct _Iter_comp_iter
     {
       _Compare _M_comp;
-
+      _GLIBCXX14_CONSTEXPR
       _Iter_comp_iter(_Compare __comp)
 	: _M_comp(__comp)
       { }
 
       template<typename _Iterator1, typename _Iterator2>
+        _GLIBCXX14_CONSTEXPR
         bool
         operator()(_Iterator1 __it1, _Iterator2 __it2)
         { return bool(_M_comp(*__it1, *__it2)); }
     };
 
   template<typename _Compare>
+    _GLIBCXX14_CONSTEXPR
     inline _Iter_comp_iter<_Compare>
     __iter_comp_iter(_Compare __comp)
     { return _Iter_comp_iter<_Compare>(__comp); }

libstdc++-v3/include/bits/stl_algo.h

@@ -3271,6 +3271,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
    *  __b) otherwise.
   */
   template<typename _Tp>
+    _GLIBCXX14_CONSTEXPR
     inline pair<const _Tp&, const _Tp&>
     minmax(const _Tp& __a, const _Tp& __b)
     {
@@ -3291,6 +3292,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
    *  __b) otherwise.
   */
   template<typename _Tp, typename _Compare>
+    _GLIBCXX14_CONSTEXPR
     inline pair<const _Tp&, const _Tp&>
     minmax(const _Tp& __a, const _Tp& __b, _Compare __comp)
     {
@@ -3299,6 +3301,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
     }
 
   template<typename _ForwardIterator, typename _Compare>
+    _GLIBCXX14_CONSTEXPR
     pair<_ForwardIterator, _ForwardIterator>
     __minmax_element(_ForwardIterator __first, _ForwardIterator __last,
 		     _Compare __comp)
@@ -3308,7 +3311,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
 	  || ++__next == __last)
 	return std::make_pair(__first, __first);
 
-      _ForwardIterator __min, __max;
+      _ForwardIterator __min{}, __max{};
       if (__comp(__next, __first))
 	{
 	  __min = __next;
@@ -3369,6 +3372,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
    *           such that no other element in the range is larger.
   */
   template<typename _ForwardIterator>
+    _GLIBCXX14_CONSTEXPR
     inline pair<_ForwardIterator, _ForwardIterator>
     minmax_element(_ForwardIterator __first, _ForwardIterator __last)
     {
@@ -3395,6 +3399,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
    *           such that no other element in the range is larger.
   */
   template<typename _ForwardIterator, typename _Compare>
+    _GLIBCXX14_CONSTEXPR
     inline pair<_ForwardIterator, _ForwardIterator>
     minmax_element(_ForwardIterator __first, _ForwardIterator __last,
 		   _Compare __comp)
@@ -3412,26 +3417,31 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
 
   // N2722 + DR 915.
   template<typename _Tp>
+    _GLIBCXX14_CONSTEXPR
     inline _Tp
     min(initializer_list<_Tp> __l)
     { return *std::min_element(__l.begin(), __l.end()); }
 
   template<typename _Tp, typename _Compare>
+    _GLIBCXX14_CONSTEXPR
     inline _Tp
     min(initializer_list<_Tp> __l, _Compare __comp)
     { return *std::min_element(__l.begin(), __l.end(), __comp); }
 
   template<typename _Tp>
+    _GLIBCXX14_CONSTEXPR
     inline _Tp
     max(initializer_list<_Tp> __l)
     { return *std::max_element(__l.begin(), __l.end()); }
 
   template<typename _Tp, typename _Compare>
+    _GLIBCXX14_CONSTEXPR
     inline _Tp
     max(initializer_list<_Tp> __l, _Compare __comp)
     { return *std::max_element(__l.begin(), __l.end(), __comp); }
 
   template<typename _Tp>
+    _GLIBCXX14_CONSTEXPR
     inline pair<_Tp, _Tp>
     minmax(initializer_list<_Tp> __l)
     {
@@ -3441,6 +3451,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
     }
 
   template<typename _Tp, typename _Compare>
+    _GLIBCXX14_CONSTEXPR
     inline pair<_Tp, _Tp>
     minmax(initializer_list<_Tp> __l, _Compare __comp)
     {
@@ -5381,6 +5392,7 @@ _GLIBCXX_BEGIN_NAMESPACE_ALGO
     }
 
   template<typename _ForwardIterator, typename _Compare>
+    _GLIBCXX14_CONSTEXPR
     _ForwardIterator
     __min_element(_ForwardIterator __first, _ForwardIterator __last,
 		  _Compare __comp)
@@ -5402,6 +5414,7 @@ _GLIBCXX_BEGIN_NAMESPACE_ALGO
    *  @return  Iterator referencing the first instance of the smallest value.
   */
   template<typename _ForwardIterator>
+    _GLIBCXX14_CONSTEXPR
     _ForwardIterator
     inline min_element(_ForwardIterator __first, _ForwardIterator __last)
     {
@@ -5425,6 +5438,7 @@ _GLIBCXX_BEGIN_NAMESPACE_ALGO
    *  according to __comp.
   */
   template<typename _ForwardIterator, typename _Compare>
+    _GLIBCXX14_CONSTEXPR
     inline _ForwardIterator
     min_element(_ForwardIterator __first, _ForwardIterator __last,
 		_Compare __comp)
@@ -5441,6 +5455,7 @@ _GLIBCXX_BEGIN_NAMESPACE_ALGO
     }
 
   template<typename _ForwardIterator, typename _Compare>
+    _GLIBCXX14_CONSTEXPR
     _ForwardIterator
     __max_element(_ForwardIterator __first, _ForwardIterator __last,
 		  _Compare __comp)
@@ -5461,6 +5476,7 @@ _GLIBCXX_BEGIN_NAMESPACE_ALGO
    *  @return  Iterator referencing the first instance of the largest value.
   */
   template<typename _ForwardIterator>
+    _GLIBCXX14_CONSTEXPR
     inline _ForwardIterator
     max_element(_ForwardIterator __first, _ForwardIterator __last)
     {
@@ -5484,6 +5500,7 @@ _GLIBCXX_BEGIN_NAMESPACE_ALGO
    *  according to __comp.
   */
   template<typename _ForwardIterator, typename _Compare>
+    _GLIBCXX14_CONSTEXPR
     inline _ForwardIterator
     max_element(_ForwardIterator __first, _ForwardIterator __last,
 		_Compare __comp)

libstdc++-v3/include/bits/stl_algobase.h

@@ -190,6 +190,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
    *  preprocessor macro.
   */
   template<typename _Tp>
+    _GLIBCXX14_CONSTEXPR
     inline const _Tp&
     min(const _Tp& __a, const _Tp& __b)
     {
@@ -213,6 +214,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
    *  preprocessor macro.
   */
   template<typename _Tp>
+    _GLIBCXX14_CONSTEXPR
     inline const _Tp&
     max(const _Tp& __a, const _Tp& __b)
     {
@@ -236,6 +238,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
    *  once, unlike a preprocessor macro.
   */
   template<typename _Tp, typename _Compare>
+    _GLIBCXX14_CONSTEXPR
     inline const _Tp&
     min(const _Tp& __a, const _Tp& __b, _Compare __comp)
     {
@@ -257,6 +260,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
    *  once, unlike a preprocessor macro.
   */
   template<typename _Tp, typename _Compare>
+    _GLIBCXX14_CONSTEXPR
     inline const _Tp&
     max(const _Tp& __a, const _Tp& __b, _Compare __comp)
     {

libstdc++-v3/testsuite/20_util/function_objects/constexpr.cc

+// { dg-options "-std=gnu++14" }
+// { dg-do compile }
+
+// Copyright (C) 2014 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/>.
+
+// 20.9.5-20.9.9
+
+#include <functional>
+
+static_assert(std::plus<int>()(1,2)==3, "");
+static_assert(std::minus<int>()(3,2)==1, "");
+static_assert(std::multiplies<int>()(3,2)==6, "");
+static_assert(std::divides<int>()(6,2)==3, "");
+static_assert(std::modulus<int>()(7,2)==1, "");
+static_assert(std::negate<int>()(-5)==5, "");
+
+static_assert(std::plus<void>()(1,2)==3, "");
+static_assert(std::minus<void>()(3,2)==1, "");
+static_assert(std::multiplies<void>()(3,2)==6, "");
+static_assert(std::divides<void>()(6,2)==3, "");
+static_assert(std::modulus<void>()(7,2)==1, "");
+static_assert(std::negate<void>()(-5)==5, "");
+
+static_assert(std::equal_to<int>()(2,2), "");
+static_assert(std::not_equal_to<int>()(1,2), "");
+static_assert(std::greater<int>()(2,1), "");
+static_assert(std::less<int>()(1,2), "");
+static_assert(std::greater_equal<int>()(2,2), "");
+static_assert(std::less_equal<int>()(2,2), "");
+
+static_assert(std::equal_to<void>()(2,2), "");
+static_assert(std::not_equal_to<void>()(1,2), "");
+static_assert(std::greater<void>()(2,1), "");
+static_assert(std::less<void>()(1,2), "");
+static_assert(std::greater_equal<void>()(2,2), "");
+static_assert(std::less_equal<void>()(2,2), "");
+
+static_assert(std::logical_and<int>()(1,1), "");
+static_assert(std::logical_or<int>()(0,1), "");
+static_assert(std::logical_not<int>()(0), "");
+
+static_assert(std::logical_and<void>()(1,1), "");
+static_assert(std::logical_or<void>()(0,1), "");
+static_assert(std::logical_not<void>()(0), "");
+
+static_assert(std::bit_and<int>()(3,2)==2, "");
+static_assert(std::bit_or<int>()(1,2)==3, "");
+static_assert(std::bit_xor<int>()(1,1)==0, "");
+static_assert(std::bit_not<int>()(std::bit_not<int>()(0))==0, "");
+
+static_assert(std::bit_and<void>()(3,2)==2, "");
+static_assert(std::bit_or<void>()(1,2)==3, "");
+static_assert(std::bit_xor<void>()(1,1)==0, "");
+static_assert(std::bit_not<void>()(std::bit_not<void>()(0))==0, "");
+
+static_assert(std::unary_negate<std::logical_not<int>>
+	      (std::logical_not<int>())(1), "");
+static_assert(std::not1(std::logical_not<int>())(1), "");
+
+static_assert(std::binary_negate<std::logical_and<int>>
+	      (std::logical_and<int>())(0,0), "");
+static_assert(std::not2(std::logical_and<int>())(0,0), "");

libstdc++-v3/testsuite/25_algorithms/max/constexpr.cc

+// { dg-options "-std=gnu++14" }
+// { dg-do compile }
+
+// Copyright (C) 2014 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>
+#include <functional>
+
+static_assert(std::max(1, 2) == 2, "");
+static_assert(std::max(2, 1, std::greater<int>()) == 1, "");
+static_assert(std::max({1, 2}) == 2, "");
+static_assert(std::max({2, 1}, std::greater<int>())==1, "");
+

libstdc++-v3/testsuite/25_algorithms/max_element/constexpr.cc

+// { dg-options "-std=gnu++14" }
+// { dg-do compile }
+
+// Copyright (C) 2014 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>
+#include <functional>
+#include <utility>
+
+constexpr std::initializer_list<int> test{1, 2};
+
+static_assert(*std::max_element(test.begin(), test.end()) == 2, "");
+static_assert(*std::max_element(test.begin(), test.end(),
+				std::greater<int>()) == 1, "");

libstdc++-v3/testsuite/25_algorithms/min/constexpr.cc

+// { dg-options "-std=gnu++14" }
+// { dg-do compile }
+
+// Copyright (C) 2014 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>
+#include <functional>
+
+static_assert(std::min(2, 1) == 1, "");
+static_assert(std::min(2, 1, std::greater<int>()) == 2, "");
+static_assert(std::min({2, 1}) == 1, "");
+static_assert(std::min({1, 2}, std::greater<int>())==2, "");
+

libstdc++-v3/testsuite/25_algorithms/min_element/constexpr.cc

+// { dg-options "-std=gnu++14" }
+// { dg-do compile }
+
+// Copyright (C) 2014 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>
+#include <functional>
+#include <utility>
+
+constexpr std::initializer_list<int> test{2, 1};
+
+static_assert(*std::min_element(test.begin(), test.end()) == 1, "");
+static_assert(*std::min_element(test.begin(), test.end(),
+				std::greater<int>()) == 2, "");

libstdc++-v3/testsuite/25_algorithms/minmax/constexpr.cc

+// { dg-options "-std=gnu++14" }
+// { dg-do compile }
+
+// Copyright (C) 2014 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>
+#include <functional>
+#include <utility>
+
+static_assert(std::minmax(2, 1) ==
+	      std::pair<const int&, const int&>(1, 2), "");
+static_assert(std::minmax(2, 1, std::greater<int>()) ==
+	      std::pair<const int&, const int&>(2, 1), "");
+static_assert(std::minmax({2, 1}) ==
+	      std::pair<int, int>(1, 2), "");
+static_assert(std::minmax({2, 1}, std::greater<int>())==
+	      std::pair<int, int>(2, 1), "");

libstdc++-v3/testsuite/25_algorithms/minmax_element/constexpr.cc

+// { dg-options "-std=gnu++14" }
+// { dg-do compile }
+
+// Copyright (C) 2014 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>
+#include <functional>
+#include <utility>
+
+constexpr std::initializer_list<int> test{2, 1};
+constexpr auto x = std::minmax_element(test.begin(), test.end());
+constexpr auto y = std::minmax_element(test.begin(), test.end(),
+				       std::greater<int>());
+static_assert(x.first == test.begin()+1, "");
+static_assert(x.second == test.begin(), "");
+static_assert(y.first == test.begin(), "");
+static_assert(y.second == test.begin()+1, "");
+

libstdc++-v3/testsuite/ext/profile/mutex_extensions_neg.cc

@@ -25,4 +25,4 @@
 
 #include <vector>
 
-// { dg-error "multiple inlined namespaces" "" { target *-*-* } 310 }
+// { dg-error "multiple inlined namespaces" "" { target *-*-* } 318 }