| // class template tuple -*- C++ -*- |
| |
| // Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009 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. |
| |
| // Under Section 7 of GPL version 3, you are granted additional |
| // permissions described in the GCC Runtime Library Exception, version |
| // 3.1, as published by the Free Software Foundation. |
| |
| // You should have received a copy of the GNU General Public License and |
| // a copy of the GCC Runtime Library Exception along with this program; |
| // see the files COPYING3 and COPYING.RUNTIME respectively. If not, see |
| // <http://www.gnu.org/licenses/>. |
| |
| /** @file tr1/tuple |
| * This is a TR1 C++ Library header. |
| */ |
| |
| // Chris Jefferson <chris@bubblescope.net> |
| // Variadic Templates support by Douglas Gregor <doug.gregor@gmail.com> |
| |
| #ifndef _GLIBCXX_TR1_TUPLE |
| #define _GLIBCXX_TR1_TUPLE 1 |
| |
| #pragma GCC system_header |
| |
| #include <utility> |
| |
| namespace std _GLIBCXX_VISIBILITY(default) |
| { |
| namespace tr1 |
| { |
| _GLIBCXX_BEGIN_NAMESPACE_VERSION |
| |
| // Adds a const reference to a non-reference type. |
| template<typename _Tp> |
| struct __add_c_ref |
| { typedef const _Tp& type; }; |
| |
| template<typename _Tp> |
| struct __add_c_ref<_Tp&> |
| { typedef _Tp& type; }; |
| |
| // Adds a reference to a non-reference type. |
| template<typename _Tp> |
| struct __add_ref |
| { typedef _Tp& type; }; |
| |
| template<typename _Tp> |
| struct __add_ref<_Tp&> |
| { typedef _Tp& type; }; |
| |
| /** |
| * Contains the actual implementation of the @c tuple template, stored |
| * as a recursive inheritance hierarchy from the first element (most |
| * derived class) to the last (least derived class). The @c Idx |
| * parameter gives the 0-based index of the element stored at this |
| * point in the hierarchy; we use it to implement a constant-time |
| * get() operation. |
| */ |
| template<int _Idx, typename... _Elements> |
| struct _Tuple_impl; |
| |
| /** |
| * Zero-element tuple implementation. This is the basis case for the |
| * inheritance recursion. |
| */ |
| template<int _Idx> |
| struct _Tuple_impl<_Idx> { }; |
| |
| /** |
| * Recursive tuple implementation. Here we store the @c Head element |
| * and derive from a @c Tuple_impl containing the remaining elements |
| * (which contains the @c Tail). |
| */ |
| template<int _Idx, typename _Head, typename... _Tail> |
| struct _Tuple_impl<_Idx, _Head, _Tail...> |
| : public _Tuple_impl<_Idx + 1, _Tail...> |
| { |
| typedef _Tuple_impl<_Idx + 1, _Tail...> _Inherited; |
| |
| _Head _M_head; |
| |
| _Inherited& _M_tail() { return *this; } |
| const _Inherited& _M_tail() const { return *this; } |
| |
| _Tuple_impl() : _Inherited(), _M_head() { } |
| |
| explicit |
| _Tuple_impl(typename __add_c_ref<_Head>::type __head, |
| typename __add_c_ref<_Tail>::type... __tail) |
| : _Inherited(__tail...), _M_head(__head) { } |
| |
| template<typename... _UElements> |
| _Tuple_impl(const _Tuple_impl<_Idx, _UElements...>& __in) |
| : _Inherited(__in._M_tail()), _M_head(__in._M_head) { } |
| |
| _Tuple_impl(const _Tuple_impl& __in) |
| : _Inherited(__in._M_tail()), _M_head(__in._M_head) { } |
| |
| template<typename... _UElements> |
| _Tuple_impl& |
| operator=(const _Tuple_impl<_Idx, _UElements...>& __in) |
| { |
| _M_head = __in._M_head; |
| _M_tail() = __in._M_tail(); |
| return *this; |
| } |
| |
| _Tuple_impl& |
| operator=(const _Tuple_impl& __in) |
| { |
| _M_head = __in._M_head; |
| _M_tail() = __in._M_tail(); |
| return *this; |
| } |
| }; |
| |
| template<typename... _Elements> |
| class tuple : public _Tuple_impl<0, _Elements...> |
| { |
| typedef _Tuple_impl<0, _Elements...> _Inherited; |
| |
| public: |
| tuple() : _Inherited() { } |
| |
| explicit |
| tuple(typename __add_c_ref<_Elements>::type... __elements) |
| : _Inherited(__elements...) { } |
| |
| template<typename... _UElements> |
| tuple(const tuple<_UElements...>& __in) |
| : _Inherited(__in) { } |
| |
| tuple(const tuple& __in) |
| : _Inherited(__in) { } |
| |
| template<typename... _UElements> |
| tuple& |
| operator=(const tuple<_UElements...>& __in) |
| { |
| static_cast<_Inherited&>(*this) = __in; |
| return *this; |
| } |
| |
| tuple& |
| operator=(const tuple& __in) |
| { |
| static_cast<_Inherited&>(*this) = __in; |
| return *this; |
| } |
| }; |
| |
| template<> class tuple<> { }; |
| |
| // 2-element tuple, with construction and assignment from a pair. |
| template<typename _T1, typename _T2> |
| class tuple<_T1, _T2> : public _Tuple_impl<0, _T1, _T2> |
| { |
| typedef _Tuple_impl<0, _T1, _T2> _Inherited; |
| |
| public: |
| tuple() : _Inherited() { } |
| |
| explicit |
| tuple(typename __add_c_ref<_T1>::type __a1, |
| typename __add_c_ref<_T2>::type __a2) |
| : _Inherited(__a1, __a2) { } |
| |
| template<typename _U1, typename _U2> |
| tuple(const tuple<_U1, _U2>& __in) |
| : _Inherited(__in) { } |
| |
| tuple(const tuple& __in) |
| : _Inherited(__in) { } |
| |
| template<typename _U1, typename _U2> |
| tuple(const pair<_U1, _U2>& __in) |
| : _Inherited(_Tuple_impl<0, |
| typename __add_c_ref<_U1>::type, |
| typename __add_c_ref<_U2>::type>(__in.first, |
| __in.second)) |
| { } |
| |
| template<typename _U1, typename _U2> |
| tuple& |
| operator=(const tuple<_U1, _U2>& __in) |
| { |
| static_cast<_Inherited&>(*this) = __in; |
| return *this; |
| } |
| |
| tuple& |
| operator=(const tuple& __in) |
| { |
| static_cast<_Inherited&>(*this) = __in; |
| return *this; |
| } |
| |
| template<typename _U1, typename _U2> |
| tuple& |
| operator=(const pair<_U1, _U2>& __in) |
| { |
| this->_M_head = __in.first; |
| this->_M_tail()._M_head = __in.second; |
| return *this; |
| } |
| }; |
| |
| |
| /// Gives the type of the ith element of a given tuple type. |
| template<int __i, typename _Tp> |
| struct tuple_element; |
| |
| /** |
| * Recursive case for tuple_element: strip off the first element in |
| * the tuple and retrieve the (i-1)th element of the remaining tuple. |
| */ |
| template<int __i, typename _Head, typename... _Tail> |
| struct tuple_element<__i, tuple<_Head, _Tail...> > |
| : tuple_element<__i - 1, tuple<_Tail...> > { }; |
| |
| /** |
| * Basis case for tuple_element: The first element is the one we're seeking. |
| */ |
| template<typename _Head, typename... _Tail> |
| struct tuple_element<0, tuple<_Head, _Tail...> > |
| { |
| typedef _Head type; |
| }; |
| |
| /// Finds the size of a given tuple type. |
| template<typename _Tp> |
| struct tuple_size; |
| |
| /// class tuple_size |
| template<typename... _Elements> |
| struct tuple_size<tuple<_Elements...> > |
| { |
| static const int value = sizeof...(_Elements); |
| }; |
| |
| template<typename... _Elements> |
| const int tuple_size<tuple<_Elements...> >::value; |
| |
| template<int __i, typename _Head, typename... _Tail> |
| inline typename __add_ref<_Head>::type |
| __get_helper(_Tuple_impl<__i, _Head, _Tail...>& __t) |
| { |
| return __t._M_head; |
| } |
| |
| template<int __i, typename _Head, typename... _Tail> |
| inline typename __add_c_ref<_Head>::type |
| __get_helper(const _Tuple_impl<__i, _Head, _Tail...>& __t) |
| { |
| return __t._M_head; |
| } |
| |
| // Return a reference (const reference) to the ith element of a tuple. |
| // Any const or non-const ref elements are returned with their original type. |
| template<int __i, typename... _Elements> |
| inline typename __add_ref< |
| typename tuple_element<__i, tuple<_Elements...> >::type |
| >::type |
| get(tuple<_Elements...>& __t) |
| { |
| return __get_helper<__i>(__t); |
| } |
| |
| template<int __i, typename... _Elements> |
| inline typename __add_c_ref< |
| typename tuple_element<__i, tuple<_Elements...> >::type |
| >::type |
| get(const tuple<_Elements...>& __t) |
| { |
| return __get_helper<__i>(__t); |
| } |
| |
| // This class helps construct the various comparison operations on tuples |
| template<int __check_equal_size, int __i, int __j, |
| typename _Tp, typename _Up> |
| struct __tuple_compare; |
| |
| template<int __i, int __j, typename _Tp, typename _Up> |
| struct __tuple_compare<0, __i, __j, _Tp, _Up> |
| { |
| static bool __eq(const _Tp& __t, const _Up& __u) |
| { |
| return (get<__i>(__t) == get<__i>(__u) && |
| __tuple_compare<0, __i+1, __j, _Tp, _Up>::__eq(__t, __u)); |
| } |
| |
| static bool __less(const _Tp& __t, const _Up& __u) |
| { |
| return ((get<__i>(__t) < get<__i>(__u)) |
| || !(get<__i>(__u) < get<__i>(__t)) && |
| __tuple_compare<0, __i+1, __j, _Tp, _Up>::__less(__t, __u)); |
| } |
| }; |
| |
| template<int __i, typename _Tp, typename _Up> |
| struct __tuple_compare<0, __i, __i, _Tp, _Up> |
| { |
| static bool __eq(const _Tp&, const _Up&) |
| { return true; } |
| |
| static bool __less(const _Tp&, const _Up&) |
| { return false; } |
| }; |
| |
| template<typename... _TElements, typename... _UElements> |
| bool |
| operator==(const tuple<_TElements...>& __t, |
| const tuple<_UElements...>& __u) |
| { |
| typedef tuple<_TElements...> _Tp; |
| typedef tuple<_UElements...> _Up; |
| return (__tuple_compare<tuple_size<_Tp>::value - tuple_size<_Up>::value, |
| 0, tuple_size<_Tp>::value, _Tp, _Up>::__eq(__t, __u)); |
| } |
| |
| template<typename... _TElements, typename... _UElements> |
| bool |
| operator<(const tuple<_TElements...>& __t, |
| const tuple<_UElements...>& __u) |
| { |
| typedef tuple<_TElements...> _Tp; |
| typedef tuple<_UElements...> _Up; |
| return (__tuple_compare<tuple_size<_Tp>::value - tuple_size<_Up>::value, |
| 0, tuple_size<_Tp>::value, _Tp, _Up>::__less(__t, __u)); |
| } |
| |
| template<typename... _TElements, typename... _UElements> |
| inline bool |
| operator!=(const tuple<_TElements...>& __t, |
| const tuple<_UElements...>& __u) |
| { return !(__t == __u); } |
| |
| template<typename... _TElements, typename... _UElements> |
| inline bool |
| operator>(const tuple<_TElements...>& __t, |
| const tuple<_UElements...>& __u) |
| { return __u < __t; } |
| |
| template<typename... _TElements, typename... _UElements> |
| inline bool |
| operator<=(const tuple<_TElements...>& __t, |
| const tuple<_UElements...>& __u) |
| { return !(__u < __t); } |
| |
| template<typename... _TElements, typename... _UElements> |
| inline bool |
| operator>=(const tuple<_TElements...>& __t, |
| const tuple<_UElements...>& __u) |
| { return !(__t < __u); } |
| |
| template<typename _Tp> |
| class reference_wrapper; |
| |
| // Helper which adds a reference to a type when given a reference_wrapper |
| template<typename _Tp> |
| struct __strip_reference_wrapper |
| { |
| typedef _Tp __type; |
| }; |
| |
| template<typename _Tp> |
| struct __strip_reference_wrapper<reference_wrapper<_Tp> > |
| { |
| typedef _Tp& __type; |
| }; |
| |
| template<typename _Tp> |
| struct __strip_reference_wrapper<const reference_wrapper<_Tp> > |
| { |
| typedef _Tp& __type; |
| }; |
| |
| template<typename... _Elements> |
| inline tuple<typename __strip_reference_wrapper<_Elements>::__type...> |
| make_tuple(_Elements... __args) |
| { |
| typedef tuple<typename __strip_reference_wrapper<_Elements>::__type...> |
| __result_type; |
| return __result_type(__args...); |
| } |
| |
| template<typename... _Elements> |
| inline tuple<_Elements&...> |
| tie(_Elements&... __args) |
| { |
| return tuple<_Elements&...>(__args...); |
| } |
| |
| // A class (and instance) which can be used in 'tie' when an element |
| // of a tuple is not required |
| struct _Swallow_assign |
| { |
| template<class _Tp> |
| _Swallow_assign& |
| operator=(const _Tp&) |
| { return *this; } |
| }; |
| |
| // TODO: Put this in some kind of shared file. |
| namespace |
| { |
| _Swallow_assign ignore; |
| }; // anonymous namespace |
| |
| _GLIBCXX_END_NAMESPACE_VERSION |
| } |
| } |
| |
| #endif // _GLIBCXX_TR1_TUPLE |