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[v3] constexpr pair additions
- From: Benjamin Kosnik <bkoz at redhat dot com>
- To: gcc-patches at gcc dot gnu dot org
- Cc: libstdc++ at gcc dot gnu dot org
- Date: Fri, 22 Jul 2011 20:19:00 -0700
- Subject: [v3] constexpr pair additions
Add constexpr markup to move/forward, and enable more std::pair
constructors.
tested x86/linux
-benjamin
2011-07-22 Benjamin Kosnik <bkoz@redhat.com>
Daniel Krugler <daniel.kruegler@googlemail.com>
* include/bits/move.h (move, forward): Mark constexpr.
* include/bits/stl_pair.h (pair): Mark move ctors constexpr.
* testsuite/20_util/pair/make_pair/constexpr.cc: New.
* testsuite/20_util/pair/cons/constexpr.cc: Add tests.
Index: include/bits/move.h
===================================================================
--- include/bits/move.h (revision 176670)
+++ include/bits/move.h (working copy)
@@ -58,12 +58,12 @@
/// forward (as per N3143)
template<typename _Tp>
- inline _Tp&&
+ inline constexpr _Tp&&
forward(typename std::remove_reference<_Tp>::type& __t) noexcept
{ return static_cast<_Tp&&>(__t); }
template<typename _Tp>
- inline _Tp&&
+ inline constexpr _Tp&&
forward(typename std::remove_reference<_Tp>::type&& __t) noexcept
{
static_assert(!std::is_lvalue_reference<_Tp>::value, "template argument"
@@ -78,7 +78,7 @@
* @return Same, moved.
*/
template<typename _Tp>
- inline typename std::remove_reference<_Tp>::type&&
+ inline constexpr typename std::remove_reference<_Tp>::type&&
move(_Tp&& __t) noexcept
{ return static_cast<typename std::remove_reference<_Tp>::type&&>(__t); }
Index: include/bits/stl_pair.h
===================================================================
--- include/bits/stl_pair.h (revision 176670)
+++ include/bits/stl_pair.h (working copy)
@@ -128,24 +128,24 @@
// DR 811.
template<class _U1, class = typename
enable_if<is_convertible<_U1, _T1>::value>::type>
- pair(_U1&& __x, const _T2& __y)
+ constexpr pair(_U1&& __x, const _T2& __y)
: first(std::forward<_U1>(__x)), second(__y) { }
template<class _U2, class = typename
enable_if<is_convertible<_U2, _T2>::value>::type>
- pair(const _T1& __x, _U2&& __y)
+ constexpr pair(const _T1& __x, _U2&& __y)
: first(__x), second(std::forward<_U2>(__y)) { }
template<class _U1, class _U2, class = typename
enable_if<__and_<is_convertible<_U1, _T1>,
is_convertible<_U2, _T2>>::value>::type>
- pair(_U1&& __x, _U2&& __y)
+ constexpr pair(_U1&& __x, _U2&& __y)
: first(std::forward<_U1>(__x)), second(std::forward<_U2>(__y)) { }
template<class _U1, class _U2, class = typename
enable_if<__and_<is_convertible<_U1, _T1>,
is_convertible<_U2, _T2>>::value>::type>
- pair(pair<_U1, _U2>&& __p)
+ constexpr pair(pair<_U1, _U2>&& __p)
: first(std::forward<_U1>(__p.first)),
second(std::forward<_U2>(__p.second)) { }
@@ -275,8 +275,8 @@
#ifdef __GXX_EXPERIMENTAL_CXX0X__
// NB: DR 706.
template<class _T1, class _T2>
- inline pair<typename __decay_and_strip<_T1>::__type,
- typename __decay_and_strip<_T2>::__type>
+ inline constexpr pair<typename __decay_and_strip<_T1>::__type,
+ typename __decay_and_strip<_T2>::__type>
make_pair(_T1&& __x, _T2&& __y)
{
typedef typename __decay_and_strip<_T1>::__type __ds_type1;
Index: testsuite/20_util/pair/make_pair/constexpr.cc
===================================================================
--- testsuite/20_util/pair/make_pair/constexpr.cc (revision 0)
+++ testsuite/20_util/pair/make_pair/constexpr.cc (revision 0)
@@ -0,0 +1,42 @@
+// { dg-do compile }
+// { dg-options "-std=gnu++0x" }
+
+// 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/>.
+
+
+// NOTE: This makes use of the fact that we know how moveable
+// is implemented on pair, and also vector. If the implementation
+// changes this test may begin to fail.
+
+#include <memory>
+#include <testsuite_hooks.h>
+
+void
+test1()
+{
+ bool test __attribute__((unused)) = true;
+ typedef std::pair<int, float> pair_type;
+ constexpr pair_type p1 = std::make_pair(22, 22.222);
+}
+
+int
+main()
+{
+ test1();
+ return 0;
+}
Index: testsuite/20_util/pair/cons/constexpr.cc
===================================================================
--- testsuite/20_util/pair/cons/constexpr.cc (revision 176670)
+++ testsuite/20_util/pair/cons/constexpr.cc (working copy)
@@ -1,7 +1,7 @@
// { dg-do compile }
// { dg-options "-std=gnu++0x" }
-// Copyright (C) 2010 Free Software Foundation, Inc.
+// Copyright (C) 2010, 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
@@ -23,17 +23,33 @@
int main()
{
+ typedef std::pair<int, int> pair_type;
+
__gnu_test::constexpr_default_constructible test1;
- test1.operator()<std::pair<int, int>>();
+ test1.operator()<pair_type>();
__gnu_test::constexpr_single_value_constructible test2;
- test2.operator()<std::pair<int, int>, std::pair<int, int>>();
- test2.operator()<std::pair<int, int>, std::pair<short, short>>();
+ test2.operator()<pair_type, pair_type>();
+ test2.operator()<pair_type, std::pair<short, short>>();
// test 3
const int i1(129);
const int i2(6);
- constexpr std::pair<int, int> p3(i1, i2);
+ constexpr pair_type p0(i1, i2);
+ // test 4
+ constexpr int i(999);
+ constexpr pair_type p1 { 44, 90 };
+ constexpr pair_type p2 { std::move(p1.first), i };
+ constexpr pair_type p3 { i, std::move(p1.second) };
+
+ constexpr pair_type p5 { 444, 904 };
+ constexpr pair_type p6 { std::move(p5.first), std::move(p5.second) };
+
+ constexpr std::pair<char, char> p8 { 'a', 'z' };
+ constexpr pair_type p9(std::move(p8));
+
+ constexpr pair_type p10(std::move(p0));
+
return 0;
}