tuple
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// <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) { }
template<typename _UHead, typename = typename
enable_if<!is_convertible<_UHead,
__uses_alloc_base>::value>::type>
constexpr _Head_base(_UHead&& __h)
: _Head(std::forward<_UHead>(__h)) { }
_Head_base(__uses_alloc0)
: _Head() { }
template<typename _Alloc>
_Head_base(__uses_alloc1<_Alloc> __a)
: _Head(allocator_arg, *__a._M_a) { }
template<typename _Alloc>
_Head_base(__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) { }
template<typename _UHead, typename = typename
enable_if<!is_convertible<_UHead,
__uses_alloc_base>::value>::type>
constexpr _Head_base(_UHead&& __h)
: _M_head_impl(std::forward<_UHead>(__h)) { }
_Head_base(__uses_alloc0)
: _M_head_impl() { }
template<typename _Alloc>
_Head_base(__uses_alloc1<_Alloc> __a)
: _M_head_impl(allocator_arg, *__a._M_a) { }
template<typename _Alloc>
_Head_base(__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(__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 __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 __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