re PR libstdc++/56785 (std::tuple of two elements does not apply empty base class optimization when one of its elements is a std::tuple with two elements)
PR libstdc++/56785 * include/std/tuple (_Tuple_impl): Remove zero-element specialization and define one-element specialization. * testsuite/20_util/tuple/56785.cc: New. From-SVN: r219785
This commit is contained in:
Jonathan Wakely
Jonathan Wakely
parent
3c16c4238b
commit
3ecec1eff7
@ -1,3 +1,10 @@
|
||||
2015-01-17 Jonathan Wakely <jwakely@redhat.com>
|
||||
|
||||
PR libstdc++/56785
|
||||
* include/std/tuple (_Tuple_impl): Remove zero-element specialization
|
||||
and define one-element specialization.
|
||||
* testsuite/20_util/tuple/56785.cc: New.
|
||||
|
||||
2015-01-17 Jonathan Wakely <jwakely@redhat.com>
|
||||
|
||||
* testsuite/22_locale/codecvt/codecvt_utf8/requirements/1.cc:
|
||||
|
||||
@ -158,30 +158,6 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
|
||||
template<std::size_t _Idx, typename... _Elements>
|
||||
struct _Tuple_impl;
|
||||
|
||||
/**
|
||||
* Zero-element tuple implementation. This is the basis case for the
|
||||
* inheritance recursion.
|
||||
*/
|
||||
template<std::size_t _Idx>
|
||||
struct _Tuple_impl<_Idx>
|
||||
{
|
||||
template<std::size_t, typename...> friend class _Tuple_impl;
|
||||
|
||||
_Tuple_impl() = default;
|
||||
|
||||
template<typename _Alloc>
|
||||
_Tuple_impl(allocator_arg_t, const _Alloc&) { }
|
||||
|
||||
template<typename _Alloc>
|
||||
_Tuple_impl(allocator_arg_t, const _Alloc&, const _Tuple_impl&) { }
|
||||
|
||||
template<typename _Alloc>
|
||||
_Tuple_impl(allocator_arg_t, const _Alloc&, _Tuple_impl&&) { }
|
||||
|
||||
protected:
|
||||
void _M_swap(_Tuple_impl&) noexcept { /* no-op */ }
|
||||
};
|
||||
|
||||
template<typename _Tp>
|
||||
struct __is_empty_non_tuple : is_empty<_Tp> { };
|
||||
|
||||
@ -358,6 +334,130 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
|
||||
}
|
||||
};
|
||||
|
||||
// Basis case of inheritance recursion.
|
||||
template<std::size_t _Idx, typename _Head>
|
||||
struct _Tuple_impl<_Idx, _Head>
|
||||
: private _Head_base<_Idx, _Head, __empty_not_final<_Head>::value>
|
||||
{
|
||||
template<std::size_t, typename...> friend class _Tuple_impl;
|
||||
|
||||
typedef _Head_base<_Idx, _Head, __empty_not_final<_Head>::value> _Base;
|
||||
|
||||
static constexpr _Head&
|
||||
_M_head(_Tuple_impl& __t) noexcept { return _Base::_M_head(__t); }
|
||||
|
||||
static constexpr const _Head&
|
||||
_M_head(const _Tuple_impl& __t) noexcept { return _Base::_M_head(__t); }
|
||||
|
||||
constexpr _Tuple_impl()
|
||||
: _Base() { }
|
||||
|
||||
explicit
|
||||
constexpr _Tuple_impl(const _Head& __head)
|
||||
: _Base(__head) { }
|
||||
|
||||
template<typename _UHead>
|
||||
explicit
|
||||
constexpr _Tuple_impl(_UHead&& __head)
|
||||
: _Base(std::forward<_UHead>(__head)) { }
|
||||
|
||||
constexpr _Tuple_impl(const _Tuple_impl&) = default;
|
||||
|
||||
constexpr
|
||||
_Tuple_impl(_Tuple_impl&& __in)
|
||||
noexcept(is_nothrow_move_constructible<_Head>::value)
|
||||
: _Base(std::forward<_Head>(_M_head(__in))) { }
|
||||
|
||||
template<typename _UHead>
|
||||
constexpr _Tuple_impl(const _Tuple_impl<_Idx, _UHead>& __in)
|
||||
: _Base(_Tuple_impl<_Idx, _UHead>::_M_head(__in)) { }
|
||||
|
||||
template<typename _UHead>
|
||||
constexpr _Tuple_impl(_Tuple_impl<_Idx, _UHead>&& __in)
|
||||
: _Base(std::forward<_UHead>(_Tuple_impl<_Idx, _UHead>::_M_head(__in)))
|
||||
{ }
|
||||
|
||||
template<typename _Alloc>
|
||||
_Tuple_impl(allocator_arg_t __tag, const _Alloc& __a)
|
||||
: _Base(__tag, __use_alloc<_Head>(__a)) { }
|
||||
|
||||
template<typename _Alloc>
|
||||
_Tuple_impl(allocator_arg_t __tag, const _Alloc& __a,
|
||||
const _Head& __head)
|
||||
: _Base(__use_alloc<_Head, _Alloc, _Head>(__a), __head) { }
|
||||
|
||||
template<typename _Alloc, typename _UHead>
|
||||
_Tuple_impl(allocator_arg_t __tag, const _Alloc& __a,
|
||||
_UHead&& __head)
|
||||
: _Base(__use_alloc<_Head, _Alloc, _UHead>(__a),
|
||||
std::forward<_UHead>(__head)) { }
|
||||
|
||||
template<typename _Alloc>
|
||||
_Tuple_impl(allocator_arg_t __tag, const _Alloc& __a,
|
||||
const _Tuple_impl& __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)
|
||||
: _Base(__use_alloc<_Head, _Alloc, _Head>(__a),
|
||||
std::forward<_Head>(_M_head(__in))) { }
|
||||
|
||||
template<typename _Alloc, typename _UHead>
|
||||
_Tuple_impl(allocator_arg_t __tag, const _Alloc& __a,
|
||||
const _Tuple_impl<_Idx, _UHead>& __in)
|
||||
: _Base(__use_alloc<_Head, _Alloc, _Head>(__a),
|
||||
_Tuple_impl<_Idx, _UHead>::_M_head(__in)) { }
|
||||
|
||||
template<typename _Alloc, typename _UHead>
|
||||
_Tuple_impl(allocator_arg_t __tag, const _Alloc& __a,
|
||||
_Tuple_impl<_Idx, _UHead>&& __in)
|
||||
: _Base(__use_alloc<_Head, _Alloc, _UHead>(__a),
|
||||
std::forward<_UHead>(_Tuple_impl<_Idx, _UHead>::_M_head(__in)))
|
||||
{ }
|
||||
|
||||
_Tuple_impl&
|
||||
operator=(const _Tuple_impl& __in)
|
||||
{
|
||||
_M_head(*this) = _M_head(__in);
|
||||
return *this;
|
||||
}
|
||||
|
||||
_Tuple_impl&
|
||||
operator=(_Tuple_impl&& __in)
|
||||
noexcept(is_nothrow_move_assignable<_Head>::value)
|
||||
{
|
||||
_M_head(*this) = std::forward<_Head>(_M_head(__in));
|
||||
return *this;
|
||||
}
|
||||
|
||||
template<typename _UHead>
|
||||
_Tuple_impl&
|
||||
operator=(const _Tuple_impl<_Idx, _UHead>& __in)
|
||||
{
|
||||
_M_head(*this) = _Tuple_impl<_Idx, _UHead>::_M_head(__in);
|
||||
return *this;
|
||||
}
|
||||
|
||||
template<typename _UHead>
|
||||
_Tuple_impl&
|
||||
operator=(_Tuple_impl<_Idx, _UHead>&& __in)
|
||||
{
|
||||
_M_head(*this)
|
||||
= std::forward<_UHead>(_Tuple_impl<_Idx, _UHead>::_M_head(__in));
|
||||
return *this;
|
||||
}
|
||||
|
||||
protected:
|
||||
void
|
||||
_M_swap(_Tuple_impl& __in)
|
||||
noexcept(noexcept(swap(std::declval<_Head&>(), std::declval<_Head&>())))
|
||||
{
|
||||
using std::swap;
|
||||
swap(_M_head(*this), _M_head(__in));
|
||||
}
|
||||
};
|
||||
|
||||
/// Primary class template, tuple
|
||||
template<typename... _Elements>
|
||||
class tuple : public _Tuple_impl<0, _Elements...>
|
||||
|
||||
32
libstdc++-v3/testsuite/20_util/tuple/56785.cc
Normal file
32
libstdc++-v3/testsuite/20_util/tuple/56785.cc
Normal file
@ -0,0 +1,32 @@
|
||||
// Copyright (C) 2015 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/>.
|
||||
|
||||
// { dg-options "-std=gnu++11" }
|
||||
// { dg-do compile }
|
||||
|
||||
#include <tuple>
|
||||
|
||||
class Empty { };
|
||||
|
||||
using std::tuple;
|
||||
using char_pair = tuple<char, char>;
|
||||
|
||||
static_assert( sizeof(tuple<Empty, char_pair>) == sizeof(char_pair),
|
||||
"Nested tuple tuple<Empty, tuple<T,T>> is too big");
|
||||
|
||||
static_assert( sizeof(tuple<char_pair, char_pair>) == (2 * sizeof(char_pair)),
|
||||
"Nested tuple<tuple<T,T, tuple<T,T>> is too big" );
|
||||
Loading…
Reference in New Issue
Block a user