Edit File: tuple
// <tuple> -*- C++ -*- // Copyright (C) 2007-2013 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 include/tuple * This is a Standard C++ Library header. */ #ifndef _GLIBCXX_TUPLE #define _GLIBCXX_TUPLE 1 #pragma GCC system_header #if __cplusplus < 201103L # include <bits/c++0x_warning.h> #else #include <utility> #include <array> #include <bits/uses_allocator.h> namespace std _GLIBCXX_VISIBILITY(default) { _GLIBCXX_BEGIN_NAMESPACE_VERSION /** * @addtogroup utilities * @{ */ // 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; }; // Adds an rvalue reference to a non-reference type. template<typename _Tp> struct __add_r_ref { typedef _Tp&& type; }; template<typename _Tp> struct __add_r_ref<_Tp&> { typedef _Tp& type; }; template<std::size_t _Idx, typename _Head, bool _IsEmptyNotFinal> struct _Head_base; template<std::size_t _Idx, typename _Head> struct _Head_base<_Idx, _Head, true> : public _Head { constexpr _Head_base() : _Head() { } constexpr _Head_base(const _Head& __h) : _Head(__h) { } constexpr _Head_base(const _Head_base&) = default; constexpr _Head_base(_Head_base&&) = default; template<typename _UHead> constexpr _Head_base(_UHead&& __h) : _Head(std::forward<_UHead>(__h)) { } _Head_base(allocator_arg_t, __uses_alloc0) : _Head() { } template<typename _Alloc> _Head_base(allocator_arg_t, __uses_alloc1<_Alloc> __a) : _Head(allocator_arg, *__a._M_a) { } template<typename _Alloc> _Head_base(allocator_arg_t, __uses_alloc2<_Alloc> __a) : _Head(*__a._M_a) { } template<typename _UHead> _Head_base(__uses_alloc0, _UHead&& __uhead) : _Head(std::forward<_UHead>(__uhead)) { } template<typename _Alloc, typename _UHead> _Head_base(__uses_alloc1<_Alloc> __a, _UHead&& __uhead) : _Head(allocator_arg, *__a._M_a, std::forward<_UHead>(__uhead)) { } template<typename _Alloc, typename _UHead> _Head_base(__uses_alloc2<_Alloc> __a, _UHead&& __uhead) : _Head(std::forward<_UHead>(__uhead), *__a._M_a) { } static constexpr _Head& _M_head(_Head_base& __b) noexcept { return __b; } static constexpr const _Head& _M_head(const _Head_base& __b) noexcept { return __b; } }; template<std::size_t _Idx, typename _Head> struct _Head_base<_Idx, _Head, false> { constexpr _Head_base() : _M_head_impl() { } constexpr _Head_base(const _Head& __h) : _M_head_impl(__h) { } constexpr _Head_base(const _Head_base&) = default; constexpr _Head_base(_Head_base&&) = default; template<typename _UHead> constexpr _Head_base(_UHead&& __h) : _M_head_impl(std::forward<_UHead>(__h)) { } _Head_base(allocator_arg_t, __uses_alloc0) : _M_head_impl() { } template<typename _Alloc> _Head_base(allocator_arg_t, __uses_alloc1<_Alloc> __a) : _M_head_impl(allocator_arg, *__a._M_a) { } template<typename _Alloc> _Head_base(allocator_arg_t, __uses_alloc2<_Alloc> __a) : _M_head_impl(*__a._M_a) { } template<typename _UHead> _Head_base(__uses_alloc0, _UHead&& __uhead) : _M_head_impl(std::forward<_UHead>(__uhead)) { } template<typename _Alloc, typename _UHead> _Head_base(__uses_alloc1<_Alloc> __a, _UHead&& __uhead) : _M_head_impl(allocator_arg, *__a._M_a, std::forward<_UHead>(__uhead)) { } template<typename _Alloc, typename _UHead> _Head_base(__uses_alloc2<_Alloc> __a, _UHead&& __uhead) : _M_head_impl(std::forward<_UHead>(__uhead), *__a._M_a) { } static constexpr _Head& _M_head(_Head_base& __b) noexcept { return __b._M_head_impl; } static constexpr const _Head& _M_head(const _Head_base& __b) noexcept { return __b._M_head_impl; } _Head _M_head_impl; }; /** * 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<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> { }; // Using EBO for elements that are tuples causes ambiguous base errors. template<typename _El0, typename... _El> struct __is_empty_non_tuple<tuple<_El0, _El...>> : false_type { }; // Use the Empty Base-class Optimization for empty, non-final types. template<typename _Tp> using __empty_not_final = typename conditional<__is_final(_Tp), false_type, __is_empty_non_tuple<_Tp>>::type; /** * 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<std::size_t _Idx, typename _Head, typename... _Tail> struct _Tuple_impl<_Idx, _Head, _Tail...> : public _Tuple_impl<_Idx + 1, _Tail...>, private _Head_base<_Idx, _Head, __empty_not_final<_Head>::value> { template<std::size_t, typename...> friend class _Tuple_impl; typedef _Tuple_impl<_Idx + 1, _Tail...> _Inherited; 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); } static constexpr _Inherited& _M_tail(_Tuple_impl& __t) noexcept { return __t; } static constexpr const _Inherited& _M_tail(const _Tuple_impl& __t) noexcept { return __t; } constexpr _Tuple_impl() : _Inherited(), _Base() { } explicit constexpr _Tuple_impl(const _Head& __head, const _Tail&... __tail) : _Inherited(__tail...), _Base(__head) { } template<typename _UHead, typename... _UTail, typename = typename enable_if<sizeof...(_Tail) == sizeof...(_UTail)>::type> explicit constexpr _Tuple_impl(_UHead&& __head, _UTail&&... __tail) : _Inherited(std::forward<_UTail>(__tail)...), _Base(std::forward<_UHead>(__head)) { } constexpr _Tuple_impl(const _Tuple_impl&) = default; constexpr _Tuple_impl(_Tuple_impl&& __in) noexcept(__and_<is_nothrow_move_constructible<_Head>, is_nothrow_move_constructible<_Inherited>>::value) : _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(_Tuple_impl<_Idx, _UElements...>::_M_tail(__in)), _Base(_Tuple_impl<_Idx, _UElements...>::_M_head(__in)) { } template<typename _UHead, typename... _UTails> constexpr _Tuple_impl(_Tuple_impl<_Idx, _UHead, _UTails...>&& __in) : _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) : _Inherited(__tag, __a), _Base(__tag, __use_alloc<_Head>(__a)) { } template<typename _Alloc> _Tuple_impl(allocator_arg_t __tag, const _Alloc& __a, const _Head& __head, const _Tail&... __tail) : _Inherited(__tag, __a, __tail...), _Base(__use_alloc<_Head, _Alloc, _Head>(__a), __head) { } template<typename _Alloc, typename _UHead, typename... _UTail, typename = typename enable_if<sizeof...(_Tail) == sizeof...(_UTail)>::type> _Tuple_impl(allocator_arg_t __tag, const _Alloc& __a, _UHead&& __head, _UTail&&... __tail) : _Inherited(__tag, __a, std::forward<_UTail>(__tail)...), _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) : _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(_M_tail(__in))), _Base(__use_alloc<_Head, _Alloc, _Head>(__a), 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, _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 (_Tuple_impl<_Idx, _UHead, _UTails...>::_M_tail(__in))), _Base(__use_alloc<_Head, _Alloc, _UHead>(__a), std::forward<_UHead> (_Tuple_impl<_Idx, _UHead, _UTails...>::_M_head(__in))) { } _Tuple_impl& operator=(const _Tuple_impl& __in) { _M_head(*this) = _M_head(__in); _M_tail(*this) = _M_tail(__in); return *this; } _Tuple_impl& operator=(_Tuple_impl&& __in) noexcept(__and_<is_nothrow_move_assignable<_Head>, is_nothrow_move_assignable<_Inherited>>::value) { _M_head(*this) = std::forward<_Head>(_M_head(__in)); _M_tail(*this) = std::move(_M_tail(__in)); return *this; } template<typename... _UElements> _Tuple_impl& operator=(const _Tuple_impl<_Idx, _UElements...>& __in) { _M_head(*this) = _Tuple_impl<_Idx, _UElements...>::_M_head(__in); _M_tail(*this) = _Tuple_impl<_Idx, _UElements...>::_M_tail(__in); return *this; } template<typename _UHead, typename... _UTails> _Tuple_impl& operator=(_Tuple_impl<_Idx, _UHead, _UTails...>&& __in) { _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; } protected: void _M_swap(_Tuple_impl& __in) noexcept(noexcept(swap(std::declval<_Head&>(), std::declval<_Head&>())) && noexcept(_M_tail(__in)._M_swap(_M_tail(__in)))) { using std::swap; swap(_M_head(*this), _M_head(__in)); _Inherited::_M_swap(_M_tail(__in)); } }; /// Primary class template, tuple template<typename... _Elements> class tuple : public _Tuple_impl<0, _Elements...> { typedef _Tuple_impl<0, _Elements...> _Inherited; public: constexpr tuple() : _Inherited() { } explicit constexpr tuple(const _Elements&... __elements) : _Inherited(__elements...) { } template<typename... _UElements, typename = typename enable_if<__and_<is_convertible<_UElements, _Elements>...>::value>::type> explicit constexpr tuple(_UElements&&... __elements) : _Inherited(std::forward<_UElements>(__elements)...) { } constexpr tuple(const tuple&) = default; constexpr tuple(tuple&&) = default; template<typename... _UElements, typename = typename enable_if<__and_<is_convertible<const _UElements&, _Elements>...>::value>::type> constexpr tuple(const tuple<_UElements...>& __in) : _Inherited(static_cast<const _Tuple_impl<0, _UElements...>&>(__in)) { } template<typename... _UElements, typename = typename enable_if<__and_<is_convertible<_UElements, _Elements>...>::value>::type> constexpr tuple(tuple<_UElements...>&& __in) : _Inherited(static_cast<_Tuple_impl<0, _UElements...>&&>(__in)) { } // Allocator-extended constructors. template<typename _Alloc> tuple(allocator_arg_t __tag, const _Alloc& __a) : _Inherited(__tag, __a) { } template<typename _Alloc> tuple(allocator_arg_t __tag, const _Alloc& __a, const _Elements&... __elements) : _Inherited(__tag, __a, __elements...) { } template<typename _Alloc, typename... _UElements, typename = typename enable_if<sizeof...(_UElements) == sizeof...(_Elements)>::type> tuple(allocator_arg_t __tag, const _Alloc& __a, _UElements&&... __elements) : _Inherited(__tag, __a, std::forward<_UElements>(__elements)...) { } template<typename _Alloc> tuple(allocator_arg_t __tag, const _Alloc& __a, const tuple& __in) : _Inherited(__tag, __a, static_cast<const _Inherited&>(__in)) { } template<typename _Alloc> tuple(allocator_arg_t __tag, const _Alloc& __a, tuple&& __in) : _Inherited(__tag, __a, static_cast<_Inherited&&>(__in)) { } template<typename _Alloc, typename... _UElements, typename = typename enable_if<sizeof...(_UElements) == sizeof...(_Elements)>::type> tuple(allocator_arg_t __tag, const _Alloc& __a, const tuple<_UElements...>& __in) : _Inherited(__tag, __a, static_cast<const _Tuple_impl<0, _UElements...>&>(__in)) { } template<typename _Alloc, typename... _UElements, typename = typename enable_if<sizeof...(_UElements) == sizeof...(_Elements)>::type> tuple(allocator_arg_t __tag, const _Alloc& __a, tuple<_UElements...>&& __in) : _Inherited(__tag, __a, static_cast<_Tuple_impl<0, _UElements...>&&>(__in)) { } tuple& operator=(const tuple& __in) { static_cast<_Inherited&>(*this) = __in; return *this; } tuple& operator=(tuple&& __in) noexcept(is_nothrow_move_assignable<_Inherited>::value) { static_cast<_Inherited&>(*this) = std::move(__in); return *this; } template<typename... _UElements, typename = typename enable_if<sizeof...(_UElements) == sizeof...(_Elements)>::type> tuple& operator=(const tuple<_UElements...>& __in) { static_cast<_Inherited&>(*this) = __in; return *this; } template<typename... _UElements, typename = typename enable_if<sizeof...(_UElements) == sizeof...(_Elements)>::type> tuple& operator=(tuple<_UElements...>&& __in) { static_cast<_Inherited&>(*this) = std::move(__in); return *this; } void swap(tuple& __in) noexcept(noexcept(__in._M_swap(__in))) { _Inherited::_M_swap(__in); } }; // Explicit specialization, zero-element tuple. template<> class tuple<> { public: void swap(tuple&) noexcept { /* no-op */ } }; /// Partial specialization, 2-element tuple. /// Includes 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: constexpr tuple() : _Inherited() { } explicit constexpr tuple(const _T1& __a1, const _T2& __a2) : _Inherited(__a1, __a2) { } template<typename _U1, typename _U2, typename = typename enable_if<__and_<is_convertible<_U1, _T1>, is_convertible<_U2, _T2>>::value>::type> explicit constexpr tuple(_U1&& __a1, _U2&& __a2) : _Inherited(std::forward<_U1>(__a1), std::forward<_U2>(__a2)) { } constexpr tuple(const tuple&) = default; constexpr tuple(tuple&&) = default; template<typename _U1, typename _U2, typename = typename enable_if<__and_<is_convertible<const _U1&, _T1>, is_convertible<const _U2&, _T2>>::value>::type> constexpr tuple(const tuple<_U1, _U2>& __in) : _Inherited(static_cast<const _Tuple_impl<0, _U1, _U2>&>(__in)) { } template<typename _U1, typename _U2, typename = typename enable_if<__and_<is_convertible<_U1, _T1>, is_convertible<_U2, _T2>>::value>::type> constexpr tuple(tuple<_U1, _U2>&& __in) : _Inherited(static_cast<_Tuple_impl<0, _U1, _U2>&&>(__in)) { } template<typename _U1, typename _U2, typename = typename enable_if<__and_<is_convertible<const _U1&, _T1>, is_convertible<const _U2&, _T2>>::value>::type> constexpr tuple(const pair<_U1, _U2>& __in) : _Inherited(__in.first, __in.second) { } template<typename _U1, typename _U2, typename = typename enable_if<__and_<is_convertible<_U1, _T1>, is_convertible<_U2, _T2>>::value>::type> constexpr tuple(pair<_U1, _U2>&& __in) : _Inherited(std::forward<_U1>(__in.first), std::forward<_U2>(__in.second)) { } // Allocator-extended constructors. template<typename _Alloc> tuple(allocator_arg_t __tag, const _Alloc& __a) : _Inherited(__tag, __a) { } template<typename _Alloc> tuple(allocator_arg_t __tag, const _Alloc& __a, const _T1& __a1, const _T2& __a2) : _Inherited(__tag, __a, __a1, __a2) { } template<typename _Alloc, typename _U1, typename _U2> tuple(allocator_arg_t __tag, const _Alloc& __a, _U1&& __a1, _U2&& __a2) : _Inherited(__tag, __a, std::forward<_U1>(__a1), std::forward<_U2>(__a2)) { } template<typename _Alloc> tuple(allocator_arg_t __tag, const _Alloc& __a, const tuple& __in) : _Inherited(__tag, __a, static_cast<const _Inherited&>(__in)) { } template<typename _Alloc> tuple(allocator_arg_t __tag, const _Alloc& __a, tuple&& __in) : _Inherited(__tag, __a, static_cast<_Inherited&&>(__in)) { } template<typename _Alloc, typename _U1, typename _U2> tuple(allocator_arg_t __tag, const _Alloc& __a, const tuple<_U1, _U2>& __in) : _Inherited(__tag, __a, static_cast<const _Tuple_impl<0, _U1, _U2>&>(__in)) { } template<typename _Alloc, typename _U1, typename _U2> tuple(allocator_arg_t __tag, const _Alloc& __a, tuple<_U1, _U2>&& __in) : _Inherited(__tag, __a, static_cast<_Tuple_impl<0, _U1, _U2>&&>(__in)) { } template<typename _Alloc, typename _U1, typename _U2> tuple(allocator_arg_t __tag, const _Alloc& __a, const pair<_U1, _U2>& __in) : _Inherited(__tag, __a, __in.first, __in.second) { } template<typename _Alloc, typename _U1, typename _U2> tuple(allocator_arg_t __tag, const _Alloc& __a, pair<_U1, _U2>&& __in) : _Inherited(__tag, __a, std::forward<_U1>(__in.first), std::forward<_U2>(__in.second)) { } tuple& operator=(const tuple& __in) { static_cast<_Inherited&>(*this) = __in; return *this; } tuple& operator=(tuple&& __in) noexcept(is_nothrow_move_assignable<_Inherited>::value) { static_cast<_Inherited&>(*this) = std::move(__in); return *this; } template<typename _U1, typename _U2> tuple& operator=(const tuple<_U1, _U2>& __in) { static_cast<_Inherited&>(*this) = __in; return *this; } template<typename _U1, typename _U2> tuple& operator=(tuple<_U1, _U2>&& __in) { static_cast<_Inherited&>(*this) = std::move(__in); return *this; } template<typename _U1, typename _U2> tuple& operator=(const pair<_U1, _U2>& __in) { this->_M_head(*this) = __in.first; this->_M_tail(*this)._M_head(*this) = __in.second; return *this; } template<typename _U1, typename _U2> tuple& operator=(pair<_U1, _U2>&& __in) { this->_M_head(*this) = std::forward<_U1>(__in.first); this->_M_tail(*this)._M_head(*this) = std::forward<_U2>(__in.second); return *this; } void swap(tuple& __in) noexcept(noexcept(__in._M_swap(__in))) { _Inherited::_M_swap(__in); } }; /// Gives the type of the ith element of a given tuple type. template<std::size_t __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<std::size_t __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; }; template<std::size_t __i, typename _Tp> struct tuple_element<__i, const _Tp> { typedef typename add_const<typename tuple_element<__i, _Tp>::type>::type type; }; template<std::size_t __i, typename _Tp> struct tuple_element<__i, volatile _Tp> { typedef typename add_volatile<typename tuple_element<__i, _Tp>::type>::type type; }; template<std::size_t __i, typename _Tp> struct tuple_element<__i, const volatile _Tp> { typedef typename add_cv<typename tuple_element<__i, _Tp>::type>::type type; }; /// Finds the size of a given tuple type. template<typename _Tp> struct tuple_size; template<typename _Tp> struct tuple_size<const _Tp> : public integral_constant< typename remove_cv<decltype(tuple_size<_Tp>::value)>::type, tuple_size<_Tp>::value> { }; template<typename _Tp> struct tuple_size<volatile _Tp> : public integral_constant< typename remove_cv<decltype(tuple_size<_Tp>::value)>::type, tuple_size<_Tp>::value> { }; template<typename _Tp> struct tuple_size<const volatile _Tp> : public integral_constant< typename remove_cv<decltype(tuple_size<_Tp>::value)>::type, tuple_size<_Tp>::value> { }; /// class tuple_size template<typename... _Elements> struct tuple_size<tuple<_Elements...>> : public integral_constant<std::size_t, sizeof...(_Elements)> { }; template<std::size_t __i, typename _Head, typename... _Tail> constexpr typename __add_ref<_Head>::type __get_helper(_Tuple_impl<__i, _Head, _Tail...>& __t) noexcept { return _Tuple_impl<__i, _Head, _Tail...>::_M_head(__t); } template<std::size_t __i, typename _Head, typename... _Tail> constexpr typename __add_c_ref<_Head>::type __get_helper(const _Tuple_impl<__i, _Head, _Tail...>& __t) noexcept { 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> constexpr typename __add_ref< typename tuple_element<__i, tuple<_Elements...>>::type >::type get(tuple<_Elements...>& __t) noexcept { return std::__get_helper<__i>(__t); } template<std::size_t __i, typename... _Elements> constexpr typename __add_c_ref< typename tuple_element<__i, tuple<_Elements...>>::type >::type get(const tuple<_Elements...>& __t) noexcept { return std::__get_helper<__i>(__t); } template<std::size_t __i, typename... _Elements> constexpr typename __add_r_ref< typename tuple_element<__i, tuple<_Elements...>>::type >::type get(tuple<_Elements...>&& __t) noexcept { return std::forward<typename tuple_element<__i, tuple<_Elements...>>::type&&>(get<__i>(__t)); } // This class helps construct the various comparison operations on tuples template<std::size_t __check_equal_size, std::size_t __i, std::size_t __j, typename _Tp, typename _Up> struct __tuple_compare; template<std::size_t __i, std::size_t __j, typename _Tp, typename _Up> struct __tuple_compare<0, __i, __j, _Tp, _Up> { static constexpr 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 constexpr 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<std::size_t __i, typename _Tp, typename _Up> struct __tuple_compare<0, __i, __i, _Tp, _Up> { static constexpr bool __eq(const _Tp&, const _Up&) { return true; } static constexpr bool __less(const _Tp&, const _Up&) { return false; } }; template<typename... _TElements, typename... _UElements> constexpr bool operator==(const tuple<_TElements...>& __t, const tuple<_UElements...>& __u) { typedef tuple<_TElements...> _Tp; typedef tuple<_UElements...> _Up; return bool(__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> constexpr bool operator<(const tuple<_TElements...>& __t, const tuple<_UElements...>& __u) { typedef tuple<_TElements...> _Tp; typedef tuple<_UElements...> _Up; return bool(__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 constexpr bool operator!=(const tuple<_TElements...>& __t, const tuple<_UElements...>& __u) { return !(__t == __u); } template<typename... _TElements, typename... _UElements> inline constexpr bool operator>(const tuple<_TElements...>& __t, const tuple<_UElements...>& __u) { return __u < __t; } template<typename... _TElements, typename... _UElements> inline constexpr bool operator<=(const tuple<_TElements...>& __t, const tuple<_UElements...>& __u) { return !(__u < __t); } template<typename... _TElements, typename... _UElements> inline constexpr bool operator>=(const tuple<_TElements...>& __t, const tuple<_UElements...>& __u) { return !(__t < __u); } // NB: DR 705. template<typename... _Elements> constexpr tuple<typename __decay_and_strip<_Elements>::__type...> make_tuple(_Elements&&... __args) { typedef tuple<typename __decay_and_strip<_Elements>::__type...> __result_type; return __result_type(std::forward<_Elements>(__args)...); } template<typename... _Elements> tuple<_Elements&&...> forward_as_tuple(_Elements&&... __args) noexcept { return tuple<_Elements&&...>(std::forward<_Elements>(__args)...); } template<typename> struct __is_tuple_like_impl : false_type { }; template<typename... _Tps> struct __is_tuple_like_impl<tuple<_Tps...>> : true_type { }; template<typename _T1, typename _T2> struct __is_tuple_like_impl<pair<_T1, _T2>> : true_type { }; template<typename _Tp, std::size_t _Nm> struct __is_tuple_like_impl<array<_Tp, _Nm>> : true_type { }; // Internal type trait that allows us to sfinae-protect tuple_cat. template<typename _Tp> struct __is_tuple_like : public __is_tuple_like_impl<typename std::remove_cv <typename std::remove_reference<_Tp>::type>::type>::type { }; // Stores a tuple of indices. Also used by bind() to extract the elements // in a tuple. template<std::size_t... _Indexes> struct _Index_tuple { typedef _Index_tuple<_Indexes..., sizeof...(_Indexes)> __next; }; // Builds an _Index_tuple<0, 1, 2, ..., _Num-1>. template<std::size_t _Num> struct _Build_index_tuple { typedef typename _Build_index_tuple<_Num - 1>::__type::__next __type; }; template<> struct _Build_index_tuple<0> { typedef _Index_tuple<> __type; }; template<std::size_t, typename, typename, std::size_t> struct __make_tuple_impl; template<std::size_t _Idx, typename _Tuple, typename... _Tp, std::size_t _Nm> struct __make_tuple_impl<_Idx, tuple<_Tp...>, _Tuple, _Nm> { typedef typename __make_tuple_impl<_Idx + 1, tuple<_Tp..., typename std::tuple_element<_Idx, _Tuple>::type>, _Tuple, _Nm>::__type __type; }; template<std::size_t _Nm, typename _Tuple, typename... _Tp> struct __make_tuple_impl<_Nm, tuple<_Tp...>, _Tuple, _Nm> { typedef tuple<_Tp...> __type; }; template<typename _Tuple> struct __do_make_tuple : public __make_tuple_impl<0, tuple<>, _Tuple, std::tuple_size<_Tuple>::value> { }; // Returns the std::tuple equivalent of a tuple-like type. template<typename _Tuple> struct __make_tuple : public __do_make_tuple<typename std::remove_cv <typename std::remove_reference<_Tuple>::type>::type> { }; // Combines several std::tuple's into a single one. template<typename...> struct __combine_tuples; template<> struct __combine_tuples<> { typedef tuple<> __type; }; template<typename... _Ts> struct __combine_tuples<tuple<_Ts...>> { typedef tuple<_Ts...> __type; }; template<typename... _T1s, typename... _T2s, typename... _Rem> struct __combine_tuples<tuple<_T1s...>, tuple<_T2s...>, _Rem...> { typedef typename __combine_tuples<tuple<_T1s..., _T2s...>, _Rem...>::__type __type; }; // Computes the result type of tuple_cat given a set of tuple-like types. template<typename... _Tpls> struct __tuple_cat_result { typedef typename __combine_tuples <typename __make_tuple<_Tpls>::__type...>::__type __type; }; // Helper to determine the index set for the first tuple-like // type of a given set. template<typename...> struct __make_1st_indices; template<> struct __make_1st_indices<> { typedef std::_Index_tuple<> __type; }; template<typename _Tp, typename... _Tpls> struct __make_1st_indices<_Tp, _Tpls...> { typedef typename std::_Build_index_tuple<std::tuple_size< typename std::remove_reference<_Tp>::type>::value>::__type __type; }; // Performs the actual concatenation by step-wise expanding tuple-like // objects into the elements, which are finally forwarded into the // result tuple. template<typename _Ret, typename _Indices, typename... _Tpls> struct __tuple_concater; template<typename _Ret, std::size_t... _Is, typename _Tp, typename... _Tpls> struct __tuple_concater<_Ret, std::_Index_tuple<_Is...>, _Tp, _Tpls...> { template<typename... _Us> static constexpr _Ret _S_do(_Tp&& __tp, _Tpls&&... __tps, _Us&&... __us) { typedef typename __make_1st_indices<_Tpls...>::__type __idx; typedef __tuple_concater<_Ret, __idx, _Tpls...> __next; return __next::_S_do(std::forward<_Tpls>(__tps)..., std::forward<_Us>(__us)..., std::get<_Is>(std::forward<_Tp>(__tp))...); } }; template<typename _Ret> struct __tuple_concater<_Ret, std::_Index_tuple<>> { template<typename... _Us> static constexpr _Ret _S_do(_Us&&... __us) { return _Ret(std::forward<_Us>(__us)...); } }; /// tuple_cat 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; typedef __tuple_concater<__ret, __idx, _Tpls...> __concater; return __concater::_S_do(std::forward<_Tpls>(__tpls)...); } /// tie template<typename... _Elements> inline tuple<_Elements&...> tie(_Elements&... __args) noexcept { return tuple<_Elements&...>(__args...); } /// swap template<typename... _Elements> inline void swap(tuple<_Elements...>& __x, tuple<_Elements...>& __y) noexcept(noexcept(__x.swap(__y))) { __x.swap(__y); } // 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> const _Swallow_assign& operator=(const _Tp&) const { return *this; } }; const _Swallow_assign ignore{}; /// Partial specialization for tuples template<typename... _Types, typename _Alloc> struct uses_allocator<tuple<_Types...>, _Alloc> : true_type { }; // See stl_pair.h... template<class _T1, class _T2> template<typename... _Args1, typename... _Args2> inline pair<_T1, _T2>:: pair(piecewise_construct_t, tuple<_Args1...> __first, tuple<_Args2...> __second) : pair(__first, __second, typename _Build_index_tuple<sizeof...(_Args1)>::__type(), typename _Build_index_tuple<sizeof...(_Args2)>::__type()) { } template<class _T1, class _T2> template<typename... _Args1, std::size_t... _Indexes1, typename... _Args2, std::size_t... _Indexes2> inline pair<_T1, _T2>:: pair(tuple<_Args1...>& __tuple1, tuple<_Args2...>& __tuple2, _Index_tuple<_Indexes1...>, _Index_tuple<_Indexes2...>) : first(std::forward<_Args1>(std::get<_Indexes1>(__tuple1))...), second(std::forward<_Args2>(std::get<_Indexes2>(__tuple2))...) { } /// @} _GLIBCXX_END_NAMESPACE_VERSION } // namespace std #endif // C++11 #endif // _GLIBCXX_TUPLE