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// class template tuple -*- C++ -*- |
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// Copyright (C) 2004-2021 Free Software Foundation, Inc. |
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// |
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// This file is part of the GNU ISO C++ Library. This library is free |
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// software; you can redistribute it and/or modify it under the |
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// terms of the GNU General Public License as published by the |
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// Free Software Foundation; either version 3, or (at your option) |
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// any later version. |
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|
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// This library is distributed in the hope that it will be useful, |
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// but WITHOUT ANY WARRANTY; without even the implied warranty of |
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// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
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// GNU General Public License for more details. |
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|
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// Under Section 7 of GPL version 3, you are granted additional |
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// permissions described in the GCC Runtime Library Exception, version |
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// 3.1, as published by the Free Software Foundation. |
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|
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// You should have received a copy of the GNU General Public License and |
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// a copy of the GCC Runtime Library Exception along with this program; |
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// see the files COPYING3 and COPYING.RUNTIME respectively. If not, see |
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// <http://www.gnu.org/licenses/>. |
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|
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/** @file tr1/tuple |
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* This is a TR1 C++ Library header. |
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*/ |
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|
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// Chris Jefferson <chris@bubblescope.net> |
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// Variadic Templates support by Douglas Gregor <doug.gregor@gmail.com> |
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|
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#ifndef _GLIBCXX_TR1_TUPLE |
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#define _GLIBCXX_TR1_TUPLE 1 |
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|
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#pragma GCC system_header |
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|
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#include <utility> |
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|
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namespace std _GLIBCXX_VISIBILITY(default) |
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{ |
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_GLIBCXX_BEGIN_NAMESPACE_VERSION |
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|
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namespace tr1 |
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{ |
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// Adds a const reference to a non-reference type. |
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template<typename _Tp> |
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struct __add_c_ref |
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{ typedef const _Tp& type; }; |
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|
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template<typename _Tp> |
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struct __add_c_ref<_Tp&> |
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{ typedef _Tp& type; }; |
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|
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// Adds a reference to a non-reference type. |
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template<typename _Tp> |
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struct __add_ref |
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{ typedef _Tp& type; }; |
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|
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template<typename _Tp> |
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struct __add_ref<_Tp&> |
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{ typedef _Tp& type; }; |
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|
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/** |
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* Contains the actual implementation of the @c tuple template, stored |
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* as a recursive inheritance hierarchy from the first element (most |
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* derived class) to the last (least derived class). The @c Idx |
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* parameter gives the 0-based index of the element stored at this |
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* point in the hierarchy; we use it to implement a constant-time |
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* get() operation. |
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*/ |
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template<int _Idx, typename... _Elements> |
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struct _Tuple_impl; |
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|
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/** |
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* Zero-element tuple implementation. This is the basis case for the |
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* inheritance recursion. |
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*/ |
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template<int _Idx> |
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struct _Tuple_impl<_Idx> { }; |
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|
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/** |
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* Recursive tuple implementation. Here we store the @c Head element |
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* and derive from a @c Tuple_impl containing the remaining elements |
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* (which contains the @c Tail). |
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*/ |
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template<int _Idx, typename _Head, typename... _Tail> |
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struct _Tuple_impl<_Idx, _Head, _Tail...> |
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: public _Tuple_impl<_Idx + 1, _Tail...> |
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{ |
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typedef _Tuple_impl<_Idx + 1, _Tail...> _Inherited; |
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|
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_Head _M_head; |
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|
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_Inherited& _M_tail() { return *this; } |
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const _Inherited& _M_tail() const { return *this; } |
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|
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_Tuple_impl() : _Inherited(), _M_head() { } |
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|
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explicit |
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_Tuple_impl(typename __add_c_ref<_Head>::type __head, |
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typename __add_c_ref<_Tail>::type... __tail) |
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: _Inherited(__tail...), _M_head(__head) { } |
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|
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template<typename... _UElements> |
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_Tuple_impl(const _Tuple_impl<_Idx, _UElements...>& __in) |
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: _Inherited(__in._M_tail()), _M_head(__in._M_head) { } |
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|
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_Tuple_impl(const _Tuple_impl& __in) |
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: _Inherited(__in._M_tail()), _M_head(__in._M_head) { } |
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|
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template<typename... _UElements> |
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_Tuple_impl& |
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operator=(const _Tuple_impl<_Idx, _UElements...>& __in) |
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{ |
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_M_head = __in._M_head; |
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_M_tail() = __in._M_tail(); |
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return *this; |
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} |
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|
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_Tuple_impl& |
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operator=(const _Tuple_impl& __in) |
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{ |
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_M_head = __in._M_head; |
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_M_tail() = __in._M_tail(); |
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return *this; |
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} |
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}; |
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|
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template<typename... _Elements> |
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class tuple : public _Tuple_impl<0, _Elements...> |
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{ |
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typedef _Tuple_impl<0, _Elements...> _Inherited; |
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|
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public: |
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tuple() : _Inherited() { } |
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|
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explicit |
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tuple(typename __add_c_ref<_Elements>::type... __elements) |
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: _Inherited(__elements...) { } |
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|
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template<typename... _UElements> |
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tuple(const tuple<_UElements...>& __in) |
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: _Inherited(__in) { } |
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|
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tuple(const tuple& __in) |
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: _Inherited(__in) { } |
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|
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template<typename... _UElements> |
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tuple& |
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operator=(const tuple<_UElements...>& __in) |
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{ |
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static_cast<_Inherited&>(*this) = __in; |
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return *this; |
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} |
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|
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tuple& |
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operator=(const tuple& __in) |
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{ |
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static_cast<_Inherited&>(*this) = __in; |
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return *this; |
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} |
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}; |
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template<> class tuple<> { }; |
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// 2-element tuple, with construction and assignment from a pair. |
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template<typename _T1, typename _T2> |
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class tuple<_T1, _T2> : public _Tuple_impl<0, _T1, _T2> |
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{ |
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typedef _Tuple_impl<0, _T1, _T2> _Inherited; |
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|
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public: |
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tuple() : _Inherited() { } |
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|
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explicit |
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tuple(typename __add_c_ref<_T1>::type __a1, |
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typename __add_c_ref<_T2>::type __a2) |
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: _Inherited(__a1, __a2) { } |
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|
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template<typename _U1, typename _U2> |
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tuple(const tuple<_U1, _U2>& __in) |
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: _Inherited(__in) { } |
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tuple(const tuple& __in) |
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: _Inherited(__in) { } |
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|
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template<typename _U1, typename _U2> |
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tuple(const pair<_U1, _U2>& __in) |
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: _Inherited(_Tuple_impl<0, |
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typename __add_c_ref<_U1>::type, |
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typename __add_c_ref<_U2>::type>(__in.first, |
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__in.second)) |
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{ } |
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|
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template<typename _U1, typename _U2> |
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tuple& |
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operator=(const tuple<_U1, _U2>& __in) |
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{ |
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static_cast<_Inherited&>(*this) = __in; |
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return *this; |
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} |
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|
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tuple& |
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operator=(const tuple& __in) |
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{ |
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static_cast<_Inherited&>(*this) = __in; |
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return *this; |
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} |
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template<typename _U1, typename _U2> |
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tuple& |
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operator=(const pair<_U1, _U2>& __in) |
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{ |
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this->_M_head = __in.first; |
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this->_M_tail()._M_head = __in.second; |
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return *this; |
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} |
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}; |
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/// Gives the type of the ith element of a given tuple type. |
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template<int __i, typename _Tp> |
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struct tuple_element; |
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/** |
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* Recursive case for tuple_element: strip off the first element in |
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* the tuple and retrieve the (i-1)th element of the remaining tuple. |
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*/ |
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template<int __i, typename _Head, typename... _Tail> |
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struct tuple_element<__i, tuple<_Head, _Tail...> > |
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: tuple_element<__i - 1, tuple<_Tail...> > { }; |
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|
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/** |
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* Basis case for tuple_element: The first element is the one we're seeking. |
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*/ |
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template<typename _Head, typename... _Tail> |
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struct tuple_element<0, tuple<_Head, _Tail...> > |
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{ |
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typedef _Head type; |
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}; |
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/// Finds the size of a given tuple type. |
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template<typename _Tp> |
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struct tuple_size; |
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/// class tuple_size |
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template<typename... _Elements> |
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struct tuple_size<tuple<_Elements...> > |
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{ |
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static const int value = sizeof...(_Elements); |
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}; |
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template<typename... _Elements> |
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const int tuple_size<tuple<_Elements...> >::value; |
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template<int __i, typename _Head, typename... _Tail> |
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inline typename __add_ref<_Head>::type |
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__get_helper(_Tuple_impl<__i, _Head, _Tail...>& __t) |
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{ |
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return __t._M_head; |
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} |
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template<int __i, typename _Head, typename... _Tail> |
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inline typename __add_c_ref<_Head>::type |
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__get_helper(const _Tuple_impl<__i, _Head, _Tail...>& __t) |
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{ |
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return __t._M_head; |
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} |
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// Return a reference (const reference) to the ith element of a tuple. |
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// Any const or non-const ref elements are returned with their original type. |
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template<int __i, typename... _Elements> |
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inline typename __add_ref< |
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typename tuple_element<__i, tuple<_Elements...> >::type |
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>::type |
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get(tuple<_Elements...>& __t) |
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{ |
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return __get_helper<__i>(__t); |
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} |
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template<int __i, typename... _Elements> |
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inline typename __add_c_ref< |
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typename tuple_element<__i, tuple<_Elements...> >::type |
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>::type |
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get(const tuple<_Elements...>& __t) |
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{ |
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return __get_helper<__i>(__t); |
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} |
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// This class helps construct the various comparison operations on tuples |
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template<int __check_equal_size, int __i, int __j, |
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typename _Tp, typename _Up> |
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struct __tuple_compare; |
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template<int __i, int __j, typename _Tp, typename _Up> |
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struct __tuple_compare<0, __i, __j, _Tp, _Up> |
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{ |
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static bool __eq(const _Tp& __t, const _Up& __u) |
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{ |
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return (get<__i>(__t) == get<__i>(__u) && |
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__tuple_compare<0, __i+1, __j, _Tp, _Up>::__eq(__t, __u)); |
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} |
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|
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static bool __less(const _Tp& __t, const _Up& __u) |
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{ |
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return ((get<__i>(__t) < get<__i>(__u)) |
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|| !(get<__i>(__u) < get<__i>(__t)) && |
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__tuple_compare<0, __i+1, __j, _Tp, _Up>::__less(__t, __u)); |
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} |
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}; |
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|
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template<int __i, typename _Tp, typename _Up> |
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struct __tuple_compare<0, __i, __i, _Tp, _Up> |
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{ |
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static bool __eq(const _Tp&, const _Up&) |
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{ return true; } |
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|
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static bool __less(const _Tp&, const _Up&) |
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{ return false; } |
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}; |
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|
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template<typename... _TElements, typename... _UElements> |
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bool |
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operator==(const tuple<_TElements...>& __t, |
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const tuple<_UElements...>& __u) |
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{ |
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typedef tuple<_TElements...> _Tp; |
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typedef tuple<_UElements...> _Up; |
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return (__tuple_compare<tuple_size<_Tp>::value - tuple_size<_Up>::value, |
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0, tuple_size<_Tp>::value, _Tp, _Up>::__eq(__t, __u)); |
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} |
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template<typename... _TElements, typename... _UElements> |
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bool |
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operator<(const tuple<_TElements...>& __t, |
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const tuple<_UElements...>& __u) |
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{ |
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typedef tuple<_TElements...> _Tp; |
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typedef tuple<_UElements...> _Up; |
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return (__tuple_compare<tuple_size<_Tp>::value - tuple_size<_Up>::value, |
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0, tuple_size<_Tp>::value, _Tp, _Up>::__less(__t, __u)); |
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} |
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|
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template<typename... _TElements, typename... _UElements> |
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inline bool |
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operator!=(const tuple<_TElements...>& __t, |
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const tuple<_UElements...>& __u) |
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{ return !(__t == __u); } |
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|
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template<typename... _TElements, typename... _UElements> |
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inline bool |
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operator>(const tuple<_TElements...>& __t, |
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const tuple<_UElements...>& __u) |
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{ return __u < __t; } |
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|
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template<typename... _TElements, typename... _UElements> |
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inline bool |
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operator<=(const tuple<_TElements...>& __t, |
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const tuple<_UElements...>& __u) |
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{ return !(__u < __t); } |
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|
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template<typename... _TElements, typename... _UElements> |
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inline bool |
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operator>=(const tuple<_TElements...>& __t, |
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const tuple<_UElements...>& __u) |
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{ return !(__t < __u); } |
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|
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template<typename _Tp> |
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class reference_wrapper; |
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|
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// Helper which adds a reference to a type when given a reference_wrapper |
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template<typename _Tp> |
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struct __strip_reference_wrapper |
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{ |
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typedef _Tp __type; |
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}; |
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|
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template<typename _Tp> |
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struct __strip_reference_wrapper<reference_wrapper<_Tp> > |
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{ |
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typedef _Tp& __type; |
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}; |
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|
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template<typename _Tp> |
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struct __strip_reference_wrapper<const reference_wrapper<_Tp> > |
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{ |
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typedef _Tp& __type; |
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}; |
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|
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template<typename... _Elements> |
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inline tuple<typename __strip_reference_wrapper<_Elements>::__type...> |
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make_tuple(_Elements... __args) |
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{ |
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typedef tuple<typename __strip_reference_wrapper<_Elements>::__type...> |
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__result_type; |
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return __result_type(__args...); |
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} |
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|
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template<typename... _Elements> |
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inline tuple<_Elements&...> |
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tie(_Elements&... __args) |
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{ |
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return tuple<_Elements&...>(__args...); |
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} |
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|
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// A class (and instance) which can be used in 'tie' when an element |
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// of a tuple is not required |
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struct _Swallow_assign |
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{ |
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template<class _Tp> |
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_Swallow_assign& |
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operator=(const _Tp&) |
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{ return *this; } |
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}; |
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|
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// TODO: Put this in some kind of shared file. |
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namespace |
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{ |
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_Swallow_assign ignore; |
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}; // anonymous namespace |
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} |
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|
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_GLIBCXX_END_NAMESPACE_VERSION |
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} |
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|
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#endif // _GLIBCXX_TR1_TUPLE |
