tuple (_Head_base<>::_M_head, [...]): Change to static constexpr functions; adjust everywhere.

2011-09-12  Daniel Krugler  <daniel.kruegler@googlemail.com>
	    Paolo Carlini  <paolo.carlini@oracle.com>

	* include/std/tuple (_Head_base<>::_M_head, _Head_base<>::_M_tail,
	_Tuple_impl<>::_M_head, _Tuple_impl<>::_M_tail): Change to static
	constexpr functions; adjust everywhere.
	(__get_helper, get): Declare constexpr all three overloads.
	(tuple_cat): Declare constexpr; use late return type to improve
	error messages.
	* include/std/utility (__pair_get<>::__get, __pair_get<>::__move_get,
	__pair_get<>::__const_get, get): Declare all constexpr.
	* include/std/array (get): Likewise.
	* testsuite/20_util/tuple/creation_functions/constexpr.cc: Re-enable
	tuple_cat test.
	* testsuite/23_containers/array/constexpr_get.cc: New.
	* testsuite/20_util/tuple/element_access/constexpr_get.cc: Likewise.
	* testsuite/20_util/pair/constexpr_get.cc: Likewise.
	* testsuite/20_util/weak_ptr/comparison/cmp_neg.cc: Adjust dg-error
	line number.

Co-Authored-By: Paolo Carlini <paolo.carlini@oracle.com>

From-SVN: r178799

libstdc++-v3/ChangeLog

+2011-09-12  Daniel Krugler  <daniel.kruegler@googlemail.com>
+	    Paolo Carlini  <paolo.carlini@oracle.com>
+
+	* include/std/tuple (_Head_base<>::_M_head, _Head_base<>::_M_tail,
+	_Tuple_impl<>::_M_head, _Tuple_impl<>::_M_tail): Change to static
+	constexpr functions; adjust everywhere.
+	(__get_helper, get): Declare constexpr all three overloads.
+	(tuple_cat): Declare constexpr; use late return type to improve
+	error messages.
+	* include/std/utility (__pair_get<>::__get, __pair_get<>::__move_get,
+	__pair_get<>::__const_get, get): Declare all constexpr.
+	* include/std/array (get): Likewise.
+	* testsuite/20_util/tuple/creation_functions/constexpr.cc: Re-enable
+	tuple_cat test.
+	* testsuite/23_containers/array/constexpr_get.cc: New.
+	* testsuite/20_util/tuple/element_access/constexpr_get.cc: Likewise.
+	* testsuite/20_util/pair/constexpr_get.cc: Likewise.
+	* testsuite/20_util/weak_ptr/comparison/cmp_neg.cc: Adjust dg-error
+	line number.
+
 2011-09-12  Jason Merrill  <jason@redhat.com>
 
 	* testsuite/20_util/is_constructible/value-2.cc: Adjust

libstdc++-v3/include/std/array

@@ -264,19 +264,19 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
     { typedef _Tp type; };
 
   template<std::size_t _Int, typename _Tp, std::size_t _Nm>
-    inline _Tp&
+    constexpr _Tp&
     get(array<_Tp, _Nm>& __arr) noexcept
-    { return __arr[_Int]; }
+    { return __arr._M_instance[_Int]; }
 
   template<std::size_t _Int, typename _Tp, std::size_t _Nm>
-    inline _Tp&&
+    constexpr _Tp&&
     get(array<_Tp, _Nm>&& __arr) noexcept
     { return std::move(get<_Int>(__arr)); }
 
   template<std::size_t _Int, typename _Tp, std::size_t _Nm>
-    inline const _Tp&
+    constexpr const _Tp&
     get(const array<_Tp, _Nm>& __arr) noexcept
-    { return __arr[_Int]; }
+    { return __arr._M_instance[_Int]; }
 
 _GLIBCXX_END_NAMESPACE_VERSION
 } // namespace

libstdc++-v3/include/std/utility

@@ -105,17 +105,17 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
     struct __pair_get<0>
     {
       template<typename _Tp1, typename _Tp2>
-        static _Tp1&
+        static constexpr _Tp1&
         __get(std::pair<_Tp1, _Tp2>& __pair) noexcept
         { return __pair.first; }
 
       template<typename _Tp1, typename _Tp2>
-        static _Tp1&&
+        static constexpr _Tp1&&
         __move_get(std::pair<_Tp1, _Tp2>&& __pair) noexcept
         { return std::forward<_Tp1>(__pair.first); }
 
       template<typename _Tp1, typename _Tp2>
-        static const _Tp1&
+        static constexpr const _Tp1&
         __const_get(const std::pair<_Tp1, _Tp2>& __pair) noexcept
         { return __pair.first; }
     };
@@ -124,33 +124,33 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
     struct __pair_get<1>
     {
       template<typename _Tp1, typename _Tp2>
-        static _Tp2&
+        static constexpr _Tp2&
         __get(std::pair<_Tp1, _Tp2>& __pair) noexcept
         { return __pair.second; }
 
       template<typename _Tp1, typename _Tp2>
-        static _Tp2&&
+        static constexpr _Tp2&&
         __move_get(std::pair<_Tp1, _Tp2>&& __pair) noexcept
         { return std::forward<_Tp2>(__pair.second); }
 
       template<typename _Tp1, typename _Tp2>
-        static const _Tp2&
+        static constexpr const _Tp2&
         __const_get(const std::pair<_Tp1, _Tp2>& __pair) noexcept
         { return __pair.second; }
     };
 
   template<std::size_t _Int, class _Tp1, class _Tp2>
-    inline typename tuple_element<_Int, std::pair<_Tp1, _Tp2>>::type&
+    constexpr typename tuple_element<_Int, std::pair<_Tp1, _Tp2>>::type&
     get(std::pair<_Tp1, _Tp2>& __in) noexcept
     { return __pair_get<_Int>::__get(__in); }
 
   template<std::size_t _Int, class _Tp1, class _Tp2>
-    inline typename tuple_element<_Int, std::pair<_Tp1, _Tp2>>::type&&
+    constexpr typename tuple_element<_Int, std::pair<_Tp1, _Tp2>>::type&&
     get(std::pair<_Tp1, _Tp2>&& __in) noexcept
     { return __pair_get<_Int>::__move_get(std::move(__in)); }
 
   template<std::size_t _Int, class _Tp1, class _Tp2>
-    inline const typename tuple_element<_Int, std::pair<_Tp1, _Tp2>>::type&
+    constexpr const typename tuple_element<_Int, std::pair<_Tp1, _Tp2>>::type&
     get(const std::pair<_Tp1, _Tp2>& __in) noexcept
     { return __pair_get<_Int>::__const_get(__in); }
 

libstdc++-v3/testsuite/20_util/pair/constexpr_get.cc

+// { dg-options "-std=gnu++0x" }
+// { dg-do compile }
+
+// Copyright (C) 2011 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 <utility>
+
+std::pair<int, int> pi;
+const std::pair<int, int> cpi;
+
+constexpr const int& cri = std::get<0>(cpi);
+constexpr int&  ri = std::get<0>(pi);
+constexpr int&& rri = std::get<0>(std::move(pi));

libstdc++-v3/testsuite/20_util/tuple/creation_functions/constexpr.cc

@@ -63,7 +63,6 @@ test_get()
 }
 
 // tuple_cat
-#if 0
 void
 test_tuple_cat()
 {
@@ -74,7 +73,6 @@ test_tuple_cat()
   constexpr tuple_type2 t2 { 55, 99, 77.77 };
   constexpr auto cat1 = std::tuple_cat(t1, t2);
 }
-#endif
 
 int
 main()
@@ -84,10 +82,7 @@ main()
 #endif
 
   test_get();
-
-#if 0
   test_tuple_cat();
-#endif
 
   return 0;
 }

libstdc++-v3/testsuite/20_util/tuple/element_access/constexpr_get.cc

+// { dg-options "-std=gnu++0x" }
+// { dg-do compile }
+
+// Copyright (C) 2011 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/>.
+
+// Tuple
+
+#include <tuple>
+
+std::tuple<int> ti;
+const std::tuple<int> cti;
+
+constexpr const int& cri = std::get<0>(cti);
+constexpr int&  ri = std::get<0>(ti);
+constexpr int&& rri = std::get<0>(std::move(ti));

libstdc++-v3/testsuite/20_util/weak_ptr/comparison/cmp_neg.cc

@@ -51,7 +51,7 @@ main()
 // { dg-warning "note" "" { target *-*-* } 485 }
 // { dg-warning "note" "" { target *-*-* } 479 }
 // { dg-warning "note" "" { target *-*-* } 468 }
-// { dg-warning "note" "" { target *-*-* } 831 }
+// { dg-warning "note" "" { target *-*-* } 840 }
 // { dg-warning "note" "" { target *-*-* } 1056 }
 // { dg-warning "note" "" { target *-*-* } 1050 }
 // { dg-warning "note" "" { target *-*-* } 342 }

libstdc++-v3/testsuite/23_containers/array/constexpr_get.cc

+// { dg-options "-std=gnu++0x" }
+// { dg-do compile }
+
+// Copyright (C) 2011 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/>.
+
+// Tuple
+
+#include <array>
+
+std::array<int, 5> ai;
+const std::array<int, 5> cai(ai);
+
+constexpr const int& cri = std::get<0>(cai);
+constexpr int&  ri = std::get<0>(ai);
+constexpr int&& rri = std::get<0>(std::move(ai));