Hi,
Daniel kindly helped adjusting <tuple> to enable constexpr for
std::tuple_cat. At the same time all the std::get overloads, for
std::pair and std::array too.
Tested x86_64-linux, committed.
Thanks,
Paolo.
////////////////////////////
2011-09-12 Daniel Krugler <daniel.krueg...@googlemail.com>
Paolo Carlini <paolo.carl...@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.
Index: include/std/tuple
===================================================================
--- include/std/tuple (revision 178791)
+++ include/std/tuple (working copy)
@@ -140,11 +140,11 @@
_Head_base(__uses_alloc2<_Alloc> __a, _UHead&& __uhead)
: _Head(std::forward<_UHead>(__uhead), *__a._M_a) { }
- _Head&
- _M_head() noexcept { return *this; }
+ static constexpr _Head&
+ _M_head(_Head_base& __b) noexcept { return __b; }
- constexpr const _Head&
- _M_head() const noexcept { return *this; }
+ static constexpr const _Head&
+ _M_head(const _Head_base& __b) noexcept { return __b; }
};
template<std::size_t _Idx, typename _Head>
@@ -186,13 +186,13 @@
_Head_base(__uses_alloc2<_Alloc> __a, _UHead&& __uhead)
: _M_head_impl(std::forward<_UHead>(__uhead), *__a._M_a) { }
- _Head&
- _M_head() noexcept { return _M_head_impl; }
+ static constexpr _Head&
+ _M_head(_Head_base& __b) noexcept { return __b._M_head_impl; }
- constexpr const _Head&
- _M_head() const noexcept { return _M_head_impl; }
+ static constexpr const _Head&
+ _M_head(const _Head_base& __b) noexcept { return __b._M_head_impl; }
- _Head _M_head_impl;
+ _Head _M_head_impl;
};
/**
@@ -245,17 +245,17 @@
typedef _Tuple_impl<_Idx + 1, _Tail...> _Inherited;
typedef _Head_base<_Idx, _Head, std::is_empty<_Head>::value> _Base;
- _Head&
- _M_head() noexcept { return _Base::_M_head(); }
+ static constexpr _Head&
+ _M_head(_Tuple_impl& __t) noexcept { return _Base::_M_head(__t); }
- constexpr const _Head&
- _M_head() const noexcept { return _Base::_M_head(); }
+ static constexpr const _Head&
+ _M_head(const _Tuple_impl& __t) noexcept { return _Base::_M_head(__t); }
- _Inherited&
- _M_tail() noexcept { return *this; }
+ static constexpr _Inherited&
+ _M_tail(_Tuple_impl& __t) noexcept { return __t; }
- constexpr const _Inherited&
- _M_tail() const noexcept { return *this; }
+ static constexpr const _Inherited&
+ _M_tail(const _Tuple_impl& __t) noexcept { return __t; }
constexpr _Tuple_impl()
: _Inherited(), _Base() { }
@@ -276,17 +276,20 @@
_Tuple_impl(_Tuple_impl&& __in)
noexcept(__and_<is_nothrow_move_constructible<_Head>,
is_nothrow_move_constructible<_Inherited>>::value)
- : _Inherited(std::move(__in._M_tail())),
- _Base(std::forward<_Head>(__in._M_head())) { }
+ : _Inherited(std::move(_M_tail(__in))),
+ _Base(std::forward<_Head>(_M_head(__in))) { }
template<typename... _UElements>
constexpr _Tuple_impl(const _Tuple_impl<_Idx, _UElements...>& __in)
- : _Inherited(__in._M_tail()), _Base(__in._M_head()) { }
+ : _Inherited(_Tuple_impl<_Idx, _UElements...>::_M_tail(__in)),
+ _Base(_Tuple_impl<_Idx, _UElements...>::_M_head(__in)) { }
template<typename _UHead, typename... _UTails>
_Tuple_impl(_Tuple_impl<_Idx, _UHead, _UTails...>&& __in)
- : _Inherited(std::move(__in._M_tail())),
- _Base(std::forward<_UHead>(__in._M_head())) { }
+ : _Inherited(std::move
+ (_Tuple_impl<_Idx, _UHead, _UTails...>::_M_tail(__in))),
+ _Base(std::forward<_UHead>
+ (_Tuple_impl<_Idx, _UHead, _UTails...>::_M_head(__in))) { }
template<typename _Alloc>
_Tuple_impl(allocator_arg_t __tag, const _Alloc& __a)
@@ -311,34 +314,38 @@
template<typename _Alloc>
_Tuple_impl(allocator_arg_t __tag, const _Alloc& __a,
const _Tuple_impl& __in)
- : _Inherited(__tag, __a, __in._M_tail()),
- _Base(__use_alloc<_Head, _Alloc, _Head>(__a), __in._M_head()) { }
+ : _Inherited(__tag, __a, _M_tail(__in)),
+ _Base(__use_alloc<_Head, _Alloc, _Head>(__a), _M_head(__in)) { }
template<typename _Alloc>
_Tuple_impl(allocator_arg_t __tag, const _Alloc& __a,
_Tuple_impl&& __in)
- : _Inherited(__tag, __a, std::move(__in._M_tail())),
+ : _Inherited(__tag, __a, std::move(_M_tail(__in))),
_Base(__use_alloc<_Head, _Alloc, _Head>(__a),
- std::forward<_Head>(__in._M_head())) { }
+ std::forward<_Head>(_M_head(__in))) { }
template<typename _Alloc, typename... _UElements>
_Tuple_impl(allocator_arg_t __tag, const _Alloc& __a,
const _Tuple_impl<_Idx, _UElements...>& __in)
- : _Inherited(__tag, __a, __in._M_tail()),
- _Base(__use_alloc<_Head, _Alloc, _Head>(__a), __in._M_head()) { }
+ : _Inherited(__tag, __a,
+ _Tuple_impl<_Idx, _UElements...>::_M_tail(__in)),
+ _Base(__use_alloc<_Head, _Alloc, _Head>(__a),
+ _Tuple_impl<_Idx, _UElements...>::_M_head(__in)) { }
template<typename _Alloc, typename _UHead, typename... _UTails>
_Tuple_impl(allocator_arg_t __tag, const _Alloc& __a,
_Tuple_impl<_Idx, _UHead, _UTails...>&& __in)
- : _Inherited(__tag, __a, std::move(__in._M_tail())),
+ : _Inherited(__tag, __a, std::move
+ (_Tuple_impl<_Idx, _UHead, _UTails...>::_M_tail(__in))),
_Base(__use_alloc<_Head, _Alloc, _UHead>(__a),
- std::forward<_UHead>(__in._M_head())) { }
+ std::forward<_UHead>
+ (_Tuple_impl<_Idx, _UHead, _UTails...>::_M_head(__in))) { }
_Tuple_impl&
operator=(const _Tuple_impl& __in)
{
- _M_head() = __in._M_head();
- _M_tail() = __in._M_tail();
+ _M_head(*this) = _M_head(__in);
+ _M_tail(*this) = _M_tail(__in);
return *this;
}
@@ -347,8 +354,8 @@
noexcept(__and_<is_nothrow_move_assignable<_Head>,
is_nothrow_move_assignable<_Inherited>>::value)
{
- _M_head() = std::forward<_Head>(__in._M_head());
- _M_tail() = std::move(__in._M_tail());
+ _M_head(*this) = std::forward<_Head>(_M_head(__in));
+ _M_tail(*this) = std::move(_M_tail(__in));
return *this;
}
@@ -356,8 +363,8 @@
_Tuple_impl&
operator=(const _Tuple_impl<_Idx, _UElements...>& __in)
{
- _M_head() = __in._M_head();
- _M_tail() = __in._M_tail();
+ _M_head(*this) = _Tuple_impl<_Idx, _UElements...>::_M_head(__in);
+ _M_tail(*this) = _Tuple_impl<_Idx, _UElements...>::_M_tail(__in);
return *this;
}
@@ -365,8 +372,10 @@
_Tuple_impl&
operator=(_Tuple_impl<_Idx, _UHead, _UTails...>&& __in)
{
- _M_head() = std::forward<_UHead>(__in._M_head());
- _M_tail() = std::move(__in._M_tail());
+ _M_head(*this) = std::forward<_UHead>
+ (_Tuple_impl<_Idx, _UHead, _UTails...>::_M_head(__in));
+ _M_tail(*this) = std::move
+ (_Tuple_impl<_Idx, _UHead, _UTails...>::_M_tail(__in));
return *this;
}
@@ -375,11 +384,11 @@
_M_swap(_Tuple_impl& __in)
noexcept(noexcept(swap(std::declval<_Head&>(),
std::declval<_Head&>()))
- && noexcept(__in._M_tail()._M_swap(__in._M_tail())))
+ && noexcept(_M_tail(__in)._M_swap(_M_tail(__in))))
{
using std::swap;
- swap(this->_M_head(), __in._M_head());
- _Inherited::_M_swap(__in._M_tail());
+ swap(_M_head(*this), _M_head(__in));
+ _Inherited::_M_swap(_M_tail(__in));
}
};
@@ -656,8 +665,8 @@
tuple&
operator=(const pair<_U1, _U2>& __in)
{
- this->_M_head() = __in.first;
- this->_M_tail()._M_head() = __in.second;
+ this->_M_head(*this) = __in.first;
+ this->_M_tail(*this)._M_head(*this) = __in.second;
return *this;
}
@@ -665,8 +674,8 @@
tuple&
operator=(pair<_U1, _U2>&& __in)
{
- this->_M_head() = std::forward<_U1>(__in.first);
- this->_M_tail()._M_head() = std::forward<_U2>(__in.second);
+ this->_M_head(*this) = std::forward<_U1>(__in.first);
+ this->_M_tail(*this)._M_head(*this) = std::forward<_U2>(__in.second);
return *this;
}
@@ -747,34 +756,34 @@
: public integral_constant<std::size_t, sizeof...(_Elements)> { };
template<std::size_t __i, typename _Head, typename... _Tail>
- inline typename __add_ref<_Head>::type
+ constexpr typename __add_ref<_Head>::type
__get_helper(_Tuple_impl<__i, _Head, _Tail...>& __t) noexcept
- { return __t._M_head(); }
+ { return _Tuple_impl<__i, _Head, _Tail...>::_M_head(__t); }
template<std::size_t __i, typename _Head, typename... _Tail>
- inline constexpr typename __add_c_ref<_Head>::type
+ constexpr typename __add_c_ref<_Head>::type
__get_helper(const _Tuple_impl<__i, _Head, _Tail...>& __t) noexcept
- { return __t._M_head(); }
+ { return _Tuple_impl<__i, _Head, _Tail...>::_M_head(__t); }
// Return a reference (const reference, rvalue reference) to the ith element
// of a tuple. Any const or non-const ref elements are returned with their
// original type.
template<std::size_t __i, typename... _Elements>
- inline typename __add_ref<
+ constexpr typename __add_ref<
typename tuple_element<__i, tuple<_Elements...>>::type
>::type
get(tuple<_Elements...>& __t) noexcept
{ return __get_helper<__i>(__t); }
template<std::size_t __i, typename... _Elements>
- inline constexpr typename __add_c_ref<
+ constexpr typename __add_c_ref<
typename tuple_element<__i, tuple<_Elements...>>::type
>::type
get(const tuple<_Elements...>& __t) noexcept
{ return __get_helper<__i>(__t); }
template<std::size_t __i, typename... _Elements>
- inline typename __add_r_ref<
+ constexpr typename __add_r_ref<
typename tuple_element<__i, tuple<_Elements...>>::type
>::type
get(tuple<_Elements...>&& __t) noexcept
@@ -880,13 +889,13 @@
template<typename, std::size_t> struct array;
template<std::size_t _Int, typename _Tp, std::size_t _Nm>
- _Tp& get(array<_Tp, _Nm>&) noexcept;
+ constexpr _Tp& get(array<_Tp, _Nm>&) noexcept;
template<std::size_t _Int, typename _Tp, std::size_t _Nm>
- _Tp&& get(array<_Tp, _Nm>&&) noexcept;
+ constexpr _Tp&& get(array<_Tp, _Nm>&&) noexcept;
template<std::size_t _Int, typename _Tp, std::size_t _Nm>
- const _Tp& get(const array<_Tp, _Nm>&) noexcept;
+ constexpr const _Tp& get(const array<_Tp, _Nm>&) noexcept;
template<typename>
struct __is_tuple_like_impl : false_type
@@ -1022,7 +1031,7 @@
struct __tuple_concater<_Ret, std::_Index_tuple<_Is...>, _Tp, _Tpls...>
{
template<typename... _Us>
- static _Ret
+ static constexpr _Ret
_S_do(_Tp&& __tp, _Tpls&&... __tps, _Us&&... __us)
{
typedef typename __make_1st_indices<_Tpls...>::__type __idx;
@@ -1037,18 +1046,18 @@
struct __tuple_concater<_Ret, std::_Index_tuple<>>
{
template<typename... _Us>
- static _Ret
+ static constexpr _Ret
_S_do(_Us&&... __us)
{
return _Ret(std::forward<_Us>(__us)...);
}
};
- template<typename... _Tpls>
- inline typename
- std::enable_if<__and_<__is_tuple_like<_Tpls>...>::value,
- typename __tuple_cat_result<_Tpls...>::__type>::type
+ template<typename... _Tpls, typename = typename
+ enable_if<__and_<__is_tuple_like<_Tpls>...>::value>::type>
+ constexpr auto
tuple_cat(_Tpls&&... __tpls)
+ -> typename __tuple_cat_result<_Tpls...>::__type
{
typedef typename __tuple_cat_result<_Tpls...>::__type __ret;
typedef typename __make_1st_indices<_Tpls...>::__type __idx;
Index: include/std/utility
===================================================================
--- include/std/utility (revision 178791)
+++ include/std/utility (working copy)
@@ -105,17 +105,17 @@
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 @@
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); }
Index: include/std/array
===================================================================
--- include/std/array (revision 178791)
+++ include/std/array (working copy)
@@ -264,19 +264,19 @@
{ 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
Index: testsuite/23_containers/array/constexpr_get.cc
===================================================================
--- testsuite/23_containers/array/constexpr_get.cc (revision 0)
+++ testsuite/23_containers/array/constexpr_get.cc (revision 0)
@@ -0,0 +1,30 @@
+// { 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));
Index: testsuite/20_util/tuple/creation_functions/constexpr.cc
===================================================================
--- testsuite/20_util/tuple/creation_functions/constexpr.cc (revision
178791)
+++ testsuite/20_util/tuple/creation_functions/constexpr.cc (working copy)
@@ -63,7 +63,6 @@
}
// tuple_cat
-#if 0
void
test_tuple_cat()
{
@@ -74,7 +73,6 @@
constexpr tuple_type2 t2 { 55, 99, 77.77 };
constexpr auto cat1 = std::tuple_cat(t1, t2);
}
-#endif
int
main()
@@ -84,10 +82,7 @@
#endif
test_get();
-
-#if 0
test_tuple_cat();
-#endif
return 0;
}
Index: testsuite/20_util/tuple/element_access/constexpr_get.cc
===================================================================
--- testsuite/20_util/tuple/element_access/constexpr_get.cc (revision 0)
+++ testsuite/20_util/tuple/element_access/constexpr_get.cc (revision 0)
@@ -0,0 +1,30 @@
+// { 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));
Index: testsuite/20_util/pair/constexpr_get.cc
===================================================================
--- testsuite/20_util/pair/constexpr_get.cc (revision 0)
+++ testsuite/20_util/pair/constexpr_get.cc (revision 0)
@@ -0,0 +1,28 @@
+// { 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));
Index: testsuite/20_util/weak_ptr/comparison/cmp_neg.cc
===================================================================
--- testsuite/20_util/weak_ptr/comparison/cmp_neg.cc (revision 178791)
+++ testsuite/20_util/weak_ptr/comparison/cmp_neg.cc (working copy)
@@ -51,7 +51,7 @@
// { 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 }
