tuple
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// <tuple> -*- C++ -*-
// Copyright (C) 2007-2021 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>
#include <bits/invoke.h>
#if __cplusplus > 201703L
# include <compare>
# define __cpp_lib_constexpr_tuple 201811L
#endif
namespace std _GLIBCXX_VISIBILITY(default)
{
_GLIBCXX_BEGIN_NAMESPACE_VERSION
/**
* @addtogroup utilities
* @{
*/
template<typename... _Elements>
class tuple;
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;
template<size_t _Idx, typename _Head,
bool = __empty_not_final<_Head>::value>
struct _Head_base;
#if __has_cpp_attribute(__no_unique_address__)
template<size_t _Idx, typename _Head>
struct _Head_base<_Idx, _Head, true>
{
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)) { }
_GLIBCXX20_CONSTEXPR
_Head_base(allocator_arg_t, __uses_alloc0)
: _M_head_impl() { }
template<typename _Alloc>
_GLIBCXX20_CONSTEXPR
_Head_base(allocator_arg_t, __uses_alloc1<_Alloc> __a)
: _M_head_impl(allocator_arg, *__a._M_a) { }
template<typename _Alloc>
_GLIBCXX20_CONSTEXPR
_Head_base(allocator_arg_t, __uses_alloc2<_Alloc> __a)
: _M_head_impl(*__a._M_a) { }
template<typename _UHead>
_GLIBCXX20_CONSTEXPR
_Head_base(__uses_alloc0, _UHead&& __uhead)
: _M_head_impl(std::forward<_UHead>(__uhead)) { }
template<typename _Alloc, typename _UHead>
_GLIBCXX20_CONSTEXPR
_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>
_GLIBCXX20_CONSTEXPR
_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; }
[[__no_unique_address__]] _Head _M_head_impl;
};
#else
template<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)) { }
_GLIBCXX20_CONSTEXPR
_Head_base(allocator_arg_t, __uses_alloc0)
: _Head() { }
template<typename _Alloc>
_GLIBCXX20_CONSTEXPR
_Head_base(allocator_arg_t, __uses_alloc1<_Alloc> __a)
: _Head(allocator_arg, *__a._M_a) { }
template<typename _Alloc>
_GLIBCXX20_CONSTEXPR
_Head_base(allocator_arg_t, __uses_alloc2<_Alloc> __a)
: _Head(*__a._M_a) { }
template<typename _UHead>
_GLIBCXX20_CONSTEXPR
_Head_base(__uses_alloc0, _UHead&& __uhead)
: _Head(std::forward<_UHead>(__uhead)) { }
template<typename _Alloc, typename _UHead>
_GLIBCXX20_CONSTEXPR
_Head_base(__uses_alloc1<_Alloc> __a, _UHead&& __uhead)
: _Head(allocator_arg, *__a._M_a, std::forward<_UHead>(__uhead)) { }
template<typename _Alloc, typename _UHead>
_GLIBCXX20_CONSTEXPR
_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; }
};
#endif
template<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)) { }
_GLIBCXX20_CONSTEXPR
_Head_base(allocator_arg_t, __uses_alloc0)
: _M_head_impl() { }
template<typename _Alloc>
_GLIBCXX20_CONSTEXPR
_Head_base(allocator_arg_t, __uses_alloc1<_Alloc> __a)
: _M_head_impl(allocator_arg, *__a._M_a) { }
template<typename _Alloc>
_GLIBCXX20_CONSTEXPR
_Head_base(allocator_arg_t, __uses_alloc2<_Alloc> __a)
: _M_head_impl(*__a._M_a) { }
template<typename _UHead>
_GLIBCXX20_CONSTEXPR
_Head_base(__uses_alloc0, _UHead&& __uhead)
: _M_head_impl(std::forward<_UHead>(__uhead)) { }
template<typename _Alloc, typename _UHead>
_GLIBCXX20_CONSTEXPR
_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>
_GLIBCXX20_CONSTEXPR
_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<size_t _Idx, typename... _Elements>
struct _Tuple_impl;
/**
* 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<size_t _Idx, typename _Head, typename... _Tail>
struct _Tuple_impl<_Idx, _Head, _Tail...>
: public _Tuple_impl<_Idx + 1, _Tail...>,
private _Head_base<_Idx, _Head>
{
template<size_t, typename...> friend struct _Tuple_impl;
typedef _Tuple_impl<_Idx + 1, _Tail...> _Inherited;
typedef _Head_base<_Idx, _Head> _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 = __enable_if_t<sizeof...(_Tail) == sizeof...(_UTail)>>
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;
// _GLIBCXX_RESOLVE_LIB_DEFECTS
// 2729. Missing SFINAE on std::pair::operator=
_Tuple_impl& operator=(const _Tuple_impl&) = delete;
_Tuple_impl(_Tuple_impl&&) = default;
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>
_GLIBCXX20_CONSTEXPR
_Tuple_impl(allocator_arg_t __tag, const _Alloc& __a)
: _Inherited(__tag, __a),
_Base(__tag, __use_alloc<_Head>(__a))
{ }
template<typename _Alloc>
_GLIBCXX20_CONSTEXPR
_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 = __enable_if_t<sizeof...(_Tail) == sizeof...(_UTail)>>
_GLIBCXX20_CONSTEXPR
_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>
_GLIBCXX20_CONSTEXPR
_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>
_GLIBCXX20_CONSTEXPR
_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 _UHead, typename... _UTails>
_GLIBCXX20_CONSTEXPR
_Tuple_impl(allocator_arg_t __tag, const _Alloc& __a,
const _Tuple_impl<_Idx, _UHead, _UTails...>& __in)
: _Inherited(__tag, __a,
_Tuple_impl<_Idx, _UHead, _UTails...>::_M_tail(__in)),
_Base(__use_alloc<_Head, _Alloc, const _UHead&>(__a),
_Tuple_impl<_Idx, _UHead, _UTails...>::_M_head(__in))
{ }
template<typename _Alloc, typename _UHead, typename... _UTails>
_GLIBCXX20_CONSTEXPR
_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)))
{ }
template<typename... _UElements>
_GLIBCXX20_CONSTEXPR
void
_M_assign(const _Tuple_impl<_Idx, _UElements...>& __in)
{
_M_head(*this) = _Tuple_impl<_Idx, _UElements...>::_M_head(__in);
_M_tail(*this)._M_assign(
_Tuple_impl<_Idx, _UElements...>::_M_tail(__in));
}
template<typename _UHead, typename... _UTails>
_GLIBCXX20_CONSTEXPR
void
_M_assign(_Tuple_impl<_Idx, _UHead, _UTails...>&& __in)
{
_M_head(*this) = std::forward<_UHead>
(_Tuple_impl<_Idx, _UHead, _UTails...>::_M_head(__in));
_M_tail(*this)._M_assign(
std::move(_Tuple_impl<_Idx, _UHead, _UTails...>::_M_tail(__in)));
}
protected:
_GLIBCXX20_CONSTEXPR
void
_M_swap(_Tuple_impl& __in)
{
using std::swap;
swap(_M_head(*this), _M_head(__in));
_Inherited::_M_swap(_M_tail(__in));
}
};
// Basis case of inheritance recursion.
template<size_t _Idx, typename _Head>
struct _Tuple_impl<_Idx, _Head>
: private _Head_base<_Idx, _Head>
{
template<size_t, typename...> friend struct _Tuple_impl;
typedef _Head_base<_Idx, _Head> _Base;
static constexpr _Head&
_M_head(_Tuple_impl& __t) noexcept { return _Base::_M_head(__t); }
static constexpr const _Head&
_M_head(const _Tuple_impl& __t) noexcept { return _Base::_M_head(__t); }
constexpr
_Tuple_impl()
: _Base() { }
explicit constexpr
_Tuple_impl(const _Head& __head)
: _Base(__head)
{ }
template<typename _UHead>
explicit constexpr
_Tuple_impl(_UHead&& __head)
: _Base(std::forward<_UHead>(__head))
{ }
constexpr _Tuple_impl(const _Tuple_impl&) = default;
// _GLIBCXX_RESOLVE_LIB_DEFECTS
// 2729. Missing SFINAE on std::pair::operator=
_Tuple_impl& operator=(const _Tuple_impl&) = delete;
#if _GLIBCXX_INLINE_VERSION
_Tuple_impl(_Tuple_impl&&) = default;
#else
constexpr
_Tuple_impl(_Tuple_impl&& __in)
noexcept(is_nothrow_move_constructible<_Head>::value)
: _Base(static_cast<_Base&&>(__in))
{ }
#endif
template<typename _UHead>
constexpr
_Tuple_impl(const _Tuple_impl<_Idx, _UHead>& __in)
: _Base(_Tuple_impl<_Idx, _UHead>::_M_head(__in))
{ }
template<typename _UHead>
constexpr
_Tuple_impl(_Tuple_impl<_Idx, _UHead>&& __in)
: _Base(std::forward<_UHead>(_Tuple_impl<_Idx, _UHead>::_M_head(__in)))
{ }
template<typename _Alloc>
_GLIBCXX20_CONSTEXPR
_Tuple_impl(allocator_arg_t __tag, const _Alloc& __a)
: _Base(__tag, __use_alloc<_Head>(__a))
{ }
template<typename _Alloc>
_GLIBCXX20_CONSTEXPR
_Tuple_impl(allocator_arg_t __tag, const _Alloc& __a,
const _Head& __head)
: _Base(__use_alloc<_Head, _Alloc, const _Head&>(__a), __head)
{ }
template<typename _Alloc, typename _UHead>
_GLIBCXX20_CONSTEXPR
_Tuple_impl(allocator_arg_t __tag, const _Alloc& __a,
_UHead&& __head)
: _Base(__use_alloc<_Head, _Alloc, _UHead>(__a),
std::forward<_UHead>(__head))
{ }
template<typename _Alloc>
_GLIBCXX20_CONSTEXPR
_Tuple_impl(allocator_arg_t __tag, const _Alloc& __a,
const _Tuple_impl& __in)
: _Base(__use_alloc<_Head, _Alloc, const _Head&>(__a), _M_head(__in))
{ }
template<typename _Alloc>
_GLIBCXX20_CONSTEXPR
_Tuple_impl(allocator_arg_t __tag, const _Alloc& __a,
_Tuple_impl&& __in)
: _Base(__use_alloc<_Head, _Alloc, _Head>(__a),
std::forward<_Head>(_M_head(__in)))
{ }
template<typename _Alloc, typename _UHead>
_GLIBCXX20_CONSTEXPR
_Tuple_impl(allocator_arg_t __tag, const _Alloc& __a,
const _Tuple_impl<_Idx, _UHead>& __in)
: _Base(__use_alloc<_Head, _Alloc, const _UHead&>(__a),
_Tuple_impl<_Idx, _UHead>::_M_head(__in))
{ }
template<typename _Alloc, typename _UHead>
_GLIBCXX20_CONSTEXPR
_Tuple_impl(allocator_arg_t __tag, const _Alloc& __a,
_Tuple_impl<_Idx, _UHead>&& __in)
: _Base(__use_alloc<_Head, _Alloc, _UHead>(__a),
std::forward<_UHead>(_Tuple_impl<_Idx, _UHead>::_M_head(__in)))
{ }
template<typename _UHead>
_GLIBCXX20_CONSTEXPR
void
_M_assign(const _Tuple_impl<_Idx, _UHead>& __in)
{
_M_head(*this) = _Tuple_impl<_Idx, _UHead>::_M_head(__in);
}
template<typename _UHead>
_GLIBCXX20_CONSTEXPR
void
_M_assign(_Tuple_impl<_Idx, _UHead>&& __in)
{
_M_head(*this)
= std::forward<_UHead>(_Tuple_impl<_Idx, _UHead>::_M_head(__in));
}
protected:
_GLIBCXX20_CONSTEXPR
void
_M_swap(_Tuple_impl& __in)
{
using std::swap;
swap(_M_head(*this), _M_head(__in));
}
};
// Concept utility functions, reused in conditionally-explicit
// constructors.
template<bool, typename... _Types>
struct _TupleConstraints
{
template<typename _Tp, typename _Up> // Workaround for PR 96592
using is_constructible
= __bool_constant<__is_constructible(_Tp, _Up)>;
// Constraint for a non-explicit constructor.
// True iff each Ti in _Types... can be constructed from Ui in _UTypes...
// and every Ui is implicitly convertible to Ti.
template<typename... _UTypes>
static constexpr bool __is_implicitly_constructible()
{
return __and_<is_constructible<_Types, _UTypes>...,
is_convertible<_UTypes, _Types>...
>::value;
}
// Constraint for a non-explicit constructor.
// True iff each Ti in _Types... can be constructed from Ui in _UTypes...
// but not every Ui is implicitly convertible to Ti.
template<typename... _UTypes>
static constexpr bool __is_explicitly_constructible()
{
return __and_<is_constructible<_Types, _UTypes>...,
__not_<__and_<is_convertible<_UTypes, _Types>...>>
>::value;
}
static constexpr bool __is_implicitly_default_constructible()
{
return __and_<std::__is_implicitly_default_constructible<_Types>...
>::value;
}
static constexpr bool __is_explicitly_default_constructible()
{
return __and_<is_default_constructible<_Types>...,
__not_<__and_<
std::__is_implicitly_default_constructible<_Types>...>
>>::value;
}
};
// Partial specialization used when a required precondition isn't met,
// e.g. when sizeof...(_Types) != sizeof...(_UTypes).
template<typename... _Types>
struct _TupleConstraints<false, _Types...>
{
template<typename... _UTypes>
static constexpr bool __is_implicitly_constructible()
{ return false; }
template<typename... _UTypes>
static constexpr bool __is_explicitly_constructible()
{ return false; }
};
/// Primary class template, tuple
template<typename... _Elements>
class tuple : public _Tuple_impl<0, _Elements...>
{
typedef _Tuple_impl<0, _Elements...> _Inherited;
template<bool _Cond>
using _TCC = _TupleConstraints<_Cond, _Elements...>;
// Constraint for non-explicit default constructor
template<bool _Dummy>
using _ImplicitDefaultCtor = __enable_if_t<
_TCC<_Dummy>::__is_implicitly_default_constructible(),
bool>;
// Constraint for explicit default constructor
template<bool _Dummy>
using _ExplicitDefaultCtor = __enable_if_t<
_TCC<_Dummy>::__is_explicitly_default_constructible(),
bool>;
// Constraint for non-explicit constructors
template<bool _Cond, typename... _Args>
using _ImplicitCtor = __enable_if_t<
_TCC<_Cond>::template __is_implicitly_constructible<_Args...>(),
bool>;
// Constraint for non-explicit constructors
template<bool _Cond, typename... _Args>
using _ExplicitCtor = __enable_if_t<
_TCC<_Cond>::template __is_explicitly_constructible<_Args...>(),
bool>;
template<typename... _UElements>
static constexpr
__enable_if_t<sizeof...(_UElements) == sizeof...(_Elements), bool>
__assignable()
{ return __and_<is_assignable<_Elements&, _UElements>...>::value; }
// Condition for noexcept-specifier of an assignment operator.
template<typename... _UElements>
static constexpr bool __nothrow_assignable()
{
return
__and_<is_nothrow_assignable<_Elements&, _UElements>...>::value;
}
// Condition for noexcept-specifier of a constructor.
template<typename... _UElements>
static constexpr bool __nothrow_constructible()
{
return
__and_<is_nothrow_constructible<_Elements, _UElements>...>::value;
}
// Constraint for tuple(_UTypes&&...) where sizeof...(_UTypes) == 1.
template<typename _Up>
static constexpr bool __valid_args()
{
return sizeof...(_Elements) == 1
&& !is_same<tuple, __remove_cvref_t<_Up>>::value;
}
// Constraint for tuple(_UTypes&&...) where sizeof...(_UTypes) > 1.
template<typename, typename, typename... _Tail>
static constexpr bool __valid_args()
{ return (sizeof...(_Tail) + 2) == sizeof...(_Elements); }
/* Constraint for constructors with a tuple<UTypes...> parameter ensures
* that the constructor is only viable when it would not interfere with
* tuple(UTypes&&...) or tuple(const tuple&) or tuple(tuple&&).
* Such constructors are only viable if:
* either sizeof...(Types) != 1,
* or (when Types... expands to T and UTypes... expands to U)
* is_convertible_v<TUPLE, T>, is_constructible_v<T, TUPLE>,
* and is_same_v<T, U> are all false.
*/
template<typename _Tuple, typename = tuple,
typename = __remove_cvref_t<_Tuple>>
struct _UseOtherCtor
: false_type
{ };
// If TUPLE is convertible to the single element in *this,
// then TUPLE should match tuple(UTypes&&...) instead.
template<typename _Tuple, typename _Tp, typename _Up>
struct _UseOtherCtor<_Tuple, tuple<_Tp>, tuple<_Up>>
: __or_<is_convertible<_Tuple, _Tp>, is_constructible<_Tp, _Tuple>>
{ };
// If TUPLE and *this each have a single element of the same type,
// then TUPLE should match a copy/move constructor instead.
template<typename _Tuple, typename _Tp>
struct _UseOtherCtor<_Tuple, tuple<_Tp>, tuple<_Tp>>
: true_type
{ };
// Return true iff sizeof...(Types) == 1 && tuple_size_v<TUPLE> == 1
// and the single element in Types can be initialized from TUPLE,
// or is the same type as tuple_element_t<0, TUPLE>.
template<typename _Tuple>
static constexpr bool __use_other_ctor()
{ return _UseOtherCtor<_Tuple>::value; }
public:
template<typename _Dummy = void,
_ImplicitDefaultCtor<is_void<_Dummy>::value> = true>
constexpr
tuple()
noexcept(__and_<is_nothrow_default_constructible<_Elements>...>::value)
: _Inherited() { }
template<typename _Dummy = void,
_ExplicitDefaultCtor<is_void<_Dummy>::value> = false>
explicit constexpr
tuple()
noexcept(__and_<is_nothrow_default_constructible<_Elements>...>::value)
: _Inherited() { }
template<bool _NotEmpty = (sizeof...(_Elements) >= 1),
_ImplicitCtor<_NotEmpty, const _Elements&...> = true>
constexpr
tuple(const _Elements&... __elements)
noexcept(__nothrow_constructible<const _Elements&...>())
: _Inherited(__elements...) { }
template<bool _NotEmpty = (sizeof...(_Elements) >= 1),
_ExplicitCtor<_NotEmpty, const _Elements&...> = false>
explicit constexpr
tuple(const _Elements&... __elements)
noexcept(__nothrow_constructible<const _Elements&...>())
: _Inherited(__elements...) { }
template<typename... _UElements,
bool _Valid = __valid_args<_UElements...>(),
_ImplicitCtor<_Valid, _UElements...> = true>
constexpr
tuple(_UElements&&... __elements)
noexcept(__nothrow_constructible<_UElements...>())
: _Inherited(std::forward<_UElements>(__elements)...) { }
template<typename... _UElements,
bool _Valid = __valid_args<_UElements...>(),
_ExplicitCtor<_Valid, _UElements...> = false>
explicit constexpr
tuple(_UElements&&... __elements)
noexcept(__nothrow_constructible<_UElements...>())
: _Inherited(std::forward<_UElements>(__elements)...) { }
constexpr tuple(const tuple&) = default;
constexpr tuple(tuple&&) = default;
template<typename... _UElements,
bool _Valid = (sizeof...(_Elements) == sizeof...(_UElements))
&& !__use_other_ctor<const tuple<_UElements...>&>(),
_ImplicitCtor<_Valid, const _UElements&...> = true>
constexpr
tuple(const tuple<_UElements...>& __in)
noexcept(__nothrow_constructible<const _UElements&...>())
: _Inherited(static_cast<const _Tuple_impl<0, _UElements...>&>(__in))
{ }
template<typename... _UElements,
bool _Valid = (sizeof...(_Elements) == sizeof...(_UElements))
&& !__use_other_ctor<const tuple<_UElements...>&>(),
_ExplicitCtor<_Valid, const _UElements&...> = false>
explicit constexpr
tuple(const tuple<_UElements...>& __in)
noexcept(__nothrow_constructible<const _UElements&...>())
: _Inherited(static_cast<const _Tuple_impl<0, _UElements...>&>(__in))
{ }
template<typename... _UElements,
bool _Valid = (sizeof...(_Elements) == sizeof...(_UElements))
&& !__use_other_ctor<tuple<_UElements...>&&>(),
_ImplicitCtor<_Valid, _UElements...> = true>
constexpr
tuple(tuple<_UElements...>&& __in)
noexcept(__nothrow_constructible<_UElements...>())
: _Inherited(static_cast<_Tuple_impl<0, _UElements...>&&>(__in)) { }
template<typename... _UElements,
bool _Valid = (sizeof...(_Elements) == sizeof...(_UElements))
&& !__use_other_ctor<tuple<_UElements...>&&>(),
_ExplicitCtor<_Valid, _UElements...> = false>
explicit constexpr
tuple(tuple<_UElements...>&& __in)
noexcept(__nothrow_constructible<_UElements...>())
: _Inherited(static_cast<_Tuple_impl<0, _UElements...>&&>(__in)) { }
// Allocator-extended constructors.
template<typename _Alloc,
_ImplicitDefaultCtor<is_object<_Alloc>::value> = true>
_GLIBCXX20_CONSTEXPR
tuple(allocator_arg_t __tag, const _Alloc& __a)
: _Inherited(__tag, __a) { }
template<typename _Alloc, bool _NotEmpty = (sizeof...(_Elements) >= 1),
_ImplicitCtor<_NotEmpty, const _Elements&...> = true>
_GLIBCXX20_CONSTEXPR
tuple(allocator_arg_t __tag, const _Alloc& __a,
const _Elements&... __elements)
: _Inherited(__tag, __a, __elements...) { }
template<typename _Alloc, bool _NotEmpty = (sizeof...(_Elements) >= 1),
_ExplicitCtor<_NotEmpty, const _Elements&...> = false>
_GLIBCXX20_CONSTEXPR
explicit
tuple(allocator_arg_t __tag, const _Alloc& __a,
const _Elements&... __elements)
: _Inherited(__tag, __a, __elements...) { }
template<typename _Alloc, typename... _UElements,
bool _Valid = __valid_args<_UElements...>(),
_ImplicitCtor<_Valid, _UElements...> = true>
_GLIBCXX20_CONSTEXPR
tuple(allocator_arg_t __tag, const _Alloc& __a,
_UElements&&... __elements)
: _Inherited(__tag, __a, std::forward<_UElements>(__elements)...)
{ }
template<typename _Alloc, typename... _UElements,
bool _Valid = __valid_args<_UElements...>(),
_ExplicitCtor<_Valid, _UElements...> = false>
_GLIBCXX20_CONSTEXPR
explicit
tuple(allocator_arg_t __tag, const _Alloc& __a,
_UElements&&... __elements)
: _Inherited(__tag, __a, std::forward<_UElements>(__elements)...)
{ }
template<typename _Alloc>
_GLIBCXX20_CONSTEXPR
tuple(allocator_arg_t __tag, const _Alloc& __a, const tuple& __in)
: _Inherited(__tag, __a, static_cast<const _Inherited&>(__in)) { }
template<typename _Alloc>
_GLIBCXX20_CONSTEXPR
tuple(allocator_arg_t __tag, const _Alloc& __a, tuple&& __in)
: _Inherited(__tag, __a, static_cast<_Inherited&&>(__in)) { }
template<typename _Alloc, typename... _UElements,
bool _Valid = (sizeof...(_Elements) == sizeof...(_UElements))
&& !__use_other_ctor<const tuple<_UElements...>&>(),
_ImplicitCtor<_Valid, const _UElements&...> = true>
_GLIBCXX20_CONSTEXPR
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,
bool _Valid = (sizeof...(_Elements) == sizeof...(_UElements))
&& !__use_other_ctor<const tuple<_UElements...>&>(),
_ExplicitCtor<_Valid, const _UElements&...> = false>
_GLIBCXX20_CONSTEXPR
explicit
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,
bool _Valid = (sizeof...(_Elements) == sizeof...(_UElements))
&& !__use_other_ctor<tuple<_UElements...>&&>(),
_ImplicitCtor<_Valid, _UElements...> = true>
_GLIBCXX20_CONSTEXPR
tuple(allocator_arg_t __tag, const _Alloc& __a,
tuple<_UElements...>&& __in)
: _Inherited(__tag, __a,
static_cast<_Tuple_impl<0, _UElements...>&&>(__in))
{ }
template<typename _Alloc, typename... _UElements,
bool _Valid = (sizeof...(_Elements) == sizeof...(_UElements))
&& !__use_other_ctor<tuple<_UElements...>&&>(),
_ExplicitCtor<_Valid, _UElements...> = false>
_GLIBCXX20_CONSTEXPR
explicit
tuple(allocator_arg_t __tag, const _Alloc& __a,
tuple<_UElements...>&& __in)
: _Inherited(__tag, __a,
static_cast<_Tuple_impl<0, _UElements...>&&>(__in))
{ }
// tuple assignment
_GLIBCXX20_CONSTEXPR
tuple&
operator=(typename conditional<__assignable<const _Elements&...>(),
const tuple&,
const __nonesuch&>::type __in)
noexcept(__nothrow_assignable<const _Elements&...>())
{
this->_M_assign(__in);
return *this;
}
_GLIBCXX20_CONSTEXPR
tuple&
operator=(typename conditional<__assignable<_Elements...>(),
tuple&&,
__nonesuch&&>::type __in)
noexcept(__nothrow_assignable<_Elements...>())
{
this->_M_assign(std::move(__in));
return *this;
}
template<typename... _UElements>
_GLIBCXX20_CONSTEXPR
__enable_if_t<__assignable<const _UElements&...>(), tuple&>
operator=(const tuple<_UElements...>& __in)
noexcept(__nothrow_assignable<const _UElements&...>())
{
this->_M_assign(__in);
return *this;
}
template<typename... _UElements>
_GLIBCXX20_CONSTEXPR
__enable_if_t<__assignable<_UElements...>(), tuple&>
operator=(tuple<_UElements...>&& __in)
noexcept(__nothrow_assignable<_UElements...>())
{
this->_M_assign(std::move(__in));
return *this;
}
// tuple swap
_GLIBCXX20_CONSTEXPR
void
swap(tuple& __in)
noexcept(__and_<__is_nothrow_swappable<_Elements>...>::value)
{ _Inherited::_M_swap(__in); }
};
#if __cpp_deduction_guides >= 201606
template<typename... _UTypes>
tuple(_UTypes...) -> tuple<_UTypes...>;
template<typename _T1, typename _T2>
tuple(pair<_T1, _T2>) -> tuple<_T1, _T2>;
template<typename _Alloc, typename... _UTypes>
tuple(allocator_arg_t, _Alloc, _UTypes...) -> tuple<_UTypes...>;
template<typename _Alloc, typename _T1, typename _T2>
tuple(allocator_arg_t, _Alloc, pair<_T1, _T2>) -> tuple<_T1, _T2>;
template<typename _Alloc, typename... _UTypes>
tuple(allocator_arg_t, _Alloc, tuple<_UTypes...>) -> tuple<_UTypes...>;
#endif
// Explicit specialization, zero-element tuple.
template<>
class tuple<>
{
public:
_GLIBCXX20_CONSTEXPR
void swap(tuple&) noexcept { /* no-op */ }
// We need the default since we're going to define no-op
// allocator constructors.
tuple() = default;
// No-op allocator constructors.
template<typename _Alloc>
_GLIBCXX20_CONSTEXPR
tuple(allocator_arg_t, const _Alloc&) noexcept { }
template<typename _Alloc>
_GLIBCXX20_CONSTEXPR
tuple(allocator_arg_t, const _Alloc&, const tuple&) noexcept { }
};
/// 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;
// Constraint for non-explicit default constructor
template<bool _Dummy, typename _U1, typename _U2>
using _ImplicitDefaultCtor = __enable_if_t<
_TupleConstraints<_Dummy, _U1, _U2>::
__is_implicitly_default_constructible(),
bool>;
// Constraint for explicit default constructor
template<bool _Dummy, typename _U1, typename _U2>
using _ExplicitDefaultCtor = __enable_if_t<
_TupleConstraints<_Dummy, _U1, _U2>::
__is_explicitly_default_constructible(),
bool>;
template<bool _Dummy>
using _TCC = _TupleConstraints<_Dummy, _T1, _T2>;
// Constraint for non-explicit constructors
template<bool _Cond, typename _U1, typename _U2>
using _ImplicitCtor = __enable_if_t<
_TCC<_Cond>::template __is_implicitly_constructible<_U1, _U2>(),
bool>;
// Constraint for non-explicit constructors
template<bool _Cond, typename _U1, typename _U2>
using _ExplicitCtor = __enable_if_t<
_TCC<_Cond>::template __is_explicitly_constructible<_U1, _U2>(),
bool>;
template<typename _U1, typename _U2>
static constexpr bool __assignable()
{
return __and_<is_assignable<_T1&, _U1>,
is_assignable<_T2&, _U2>>::value;
}
template<typename _U1, typename _U2>
static constexpr bool __nothrow_assignable()
{
return __and_<is_nothrow_assignable<_T1&, _U1>,
is_nothrow_assignable<_T2&, _U2>>::value;
}
template<typename _U1, typename _U2>
static constexpr bool __nothrow_constructible()
{
return __and_<is_nothrow_constructible<_T1, _U1>,
is_nothrow_constructible<_T2, _U2>>::value;
}
static constexpr bool __nothrow_default_constructible()
{
return __and_<is_nothrow_default_constructible<_T1>,
is_nothrow_default_constructible<_T2>>::value;
}
template<typename _U1>
static constexpr bool __is_alloc_arg()
{ return is_same<__remove_cvref_t<_U1>, allocator_arg_t>::value; }
public:
template<bool _Dummy = true,
_ImplicitDefaultCtor<_Dummy, _T1, _T2> = true>
constexpr
tuple()
noexcept(__nothrow_default_constructible())
: _Inherited() { }
template<bool _Dummy = true,
_ExplicitDefaultCtor<_Dummy, _T1, _T2> = false>
explicit constexpr
tuple()
noexcept(__nothrow_default_constructible())
: _Inherited() { }
template<bool _Dummy = true,
_ImplicitCtor<_Dummy, const _T1&, const _T2&> = true>
constexpr
tuple(const _T1& __a1, const _T2& __a2)
noexcept(__nothrow_constructible<const _T1&, const _T2&>())
: _Inherited(__a1, __a2) { }
template<bool _Dummy = true,
_ExplicitCtor<_Dummy, const _T1&, const _T2&> = false>
explicit constexpr
tuple(const _T1& __a1, const _T2& __a2)
noexcept(__nothrow_constructible<const _T1&, const _T2&>())
: _Inherited(__a1, __a2) { }
template<typename _U1, typename _U2,
_ImplicitCtor<!__is_alloc_arg<_U1>(), _U1, _U2> = true>
constexpr
tuple(_U1&& __a1, _U2&& __a2)
noexcept(__nothrow_constructible<_U1, _U2>())
: _Inherited(std::forward<_U1>(__a1), std::forward<_U2>(__a2)) { }
template<typename _U1, typename _U2,
_ExplicitCtor<!__is_alloc_arg<_U1>(), _U1, _U2> = false>
explicit constexpr
tuple(_U1&& __a1, _U2&& __a2)
noexcept(__nothrow_constructible<_U1, _U2>())
: _Inherited(std::forward<_U1>(__a1), std::forward<_U2>(__a2)) { }
constexpr tuple(const tuple&) = default;
constexpr tuple(tuple&&) = default;
template<typename _U1, typename _U2,
_ImplicitCtor<true, const _U1&, const _U2&> = true>
constexpr
tuple(const tuple<_U1, _U2>& __in)
noexcept(__nothrow_constructible<const _U1&, const _U2&>())
: _Inherited(static_cast<const _Tuple_impl<0, _U1, _U2>&>(__in)) { }
template<typename _U1, typename _U2,
_ExplicitCtor<true, const _U1&, const _U2&> = false>
explicit constexpr
tuple(const tuple<_U1, _U2>& __in)
noexcept(__nothrow_constructible<const _U1&, const _U2&>())
: _Inherited(static_cast<const _Tuple_impl<0, _U1, _U2>&>(__in)) { }
template<typename _U1, typename _U2,
_ImplicitCtor<true, _U1, _U2> = true>
constexpr
tuple(tuple<_U1, _U2>&& __in)
noexcept(__nothrow_constructible<_U1, _U2>())
: _Inherited(static_cast<_Tuple_impl<0, _U1, _U2>&&>(__in)) { }
template<typename _U1, typename _U2,
_ExplicitCtor<true, _U1, _U2> = false>
explicit constexpr
tuple(tuple<_U1, _U2>&& __in)
noexcept(__nothrow_constructible<_U1, _U2>())
: _Inherited(static_cast<_Tuple_impl<0, _U1, _U2>&&>(__in)) { }
template<typename _U1, typename _U2,
_ImplicitCtor<true, const _U1&, const _U2&> = true>
constexpr
tuple(const pair<_U1, _U2>& __in)
noexcept(__nothrow_constructible<const _U1&, const _U2&>())
: _Inherited(__in.first, __in.second) { }
template<typename _U1, typename _U2,
_ExplicitCtor<true, const _U1&, const _U2&> = false>
explicit constexpr
tuple(const pair<_U1, _U2>& __in)
noexcept(__nothrow_constructible<const _U1&, const _U2&>())
: _Inherited(__in.first, __in.second) { }
template<typename _U1, typename _U2,
_ImplicitCtor<true, _U1, _U2> = true>
constexpr
tuple(pair<_U1, _U2>&& __in)
noexcept(__nothrow_constructible<_U1, _U2>())
: _Inherited(std::forward<_U1>(__in.first),
std::forward<_U2>(__in.second)) { }
template<typename _U1, typename _U2,
_ExplicitCtor<true, _U1, _U2> = false>
explicit constexpr
tuple(pair<_U1, _U2>&& __in)
noexcept(__nothrow_constructible<_U1, _U2>())
: _Inherited(std::forward<_U1>(__in.first),
std::forward<_U2>(__in.second)) { }
// Allocator-extended constructors.
template<typename _Alloc,
_ImplicitDefaultCtor<is_object<_Alloc>::value, _T1, _T2> = true>
_GLIBCXX20_CONSTEXPR
tuple(allocator_arg_t __tag, const _Alloc& __a)
: _Inherited(__tag, __a) { }
template<typename _Alloc, bool _Dummy = true,
_ImplicitCtor<_Dummy, const _T1&, const _T2&> = true>
_GLIBCXX20_CONSTEXPR
tuple(allocator_arg_t __tag, const _Alloc& __a,
const _T1& __a1, const _T2& __a2)
: _Inherited(__tag, __a, __a1, __a2) { }
template<typename _Alloc, bool _Dummy = true,
_ExplicitCtor<_Dummy, const _T1&, const _T2&> = false>
explicit
_GLIBCXX20_CONSTEXPR
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,
_ImplicitCtor<true, _U1, _U2> = true>
_GLIBCXX20_CONSTEXPR
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, typename _U1, typename _U2,
_ExplicitCtor<true, _U1, _U2> = false>
explicit
_GLIBCXX20_CONSTEXPR
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>
_GLIBCXX20_CONSTEXPR
tuple(allocator_arg_t __tag, const _Alloc& __a, const tuple& __in)
: _Inherited(__tag, __a, static_cast<const _Inherited&>(__in)) { }
template<typename _Alloc>
_GLIBCXX20_CONSTEXPR
tuple(allocator_arg_t __tag, const _Alloc& __a, tuple&& __in)
: _Inherited(__tag, __a, static_cast<_Inherited&&>(__in)) { }
template<typename _Alloc, typename _U1, typename _U2,
_ImplicitCtor<true, const _U1&, const _U2&> = true>
_GLIBCXX20_CONSTEXPR
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,
_ExplicitCtor<true, const _U1&, const _U2&> = false>
explicit
_GLIBCXX20_CONSTEXPR
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,
_ImplicitCtor<true, _U1, _U2> = true>
_GLIBCXX20_CONSTEXPR
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,
_ExplicitCtor<true, _U1, _U2> = false>
explicit
_GLIBCXX20_CONSTEXPR
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,
_ImplicitCtor<true, const _U1&, const _U2&> = true>
_GLIBCXX20_CONSTEXPR
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,
_ExplicitCtor<true, const _U1&, const _U2&> = false>
explicit
_GLIBCXX20_CONSTEXPR
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,
_ImplicitCtor<true, _U1, _U2> = true>
_GLIBCXX20_CONSTEXPR
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)) { }
template<typename _Alloc, typename _U1, typename _U2,
_ExplicitCtor<true, _U1, _U2> = false>
explicit
_GLIBCXX20_CONSTEXPR
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 assignment.
_GLIBCXX20_CONSTEXPR
tuple&
operator=(typename conditional<__assignable<const _T1&, const _T2&>(),
const tuple&,
const __nonesuch&>::type __in)
noexcept(__nothrow_assignable<const _T1&, const _T2&>())
{
this->_M_assign(__in);
return *this;
}
_GLIBCXX20_CONSTEXPR
tuple&
operator=(typename conditional<__assignable<_T1, _T2>(),
tuple&&,
__nonesuch&&>::type __in)
noexcept(__nothrow_assignable<_T1, _T2>())
{
this->_M_assign(std::move(__in));
return *this;
}
template<typename _U1, typename _U2>
_GLIBCXX20_CONSTEXPR
__enable_if_t<__assignable<const _U1&, const _U2&>(), tuple&>
operator=(const tuple<_U1, _U2>& __in)
noexcept(__nothrow_assignable<const _U1&, const _U2&>())
{
this->_M_assign(__in);
return *this;
}
template<typename _U1, typename _U2>
_GLIBCXX20_CONSTEXPR
__enable_if_t<__assignable<_U1, _U2>(), tuple&>
operator=(tuple<_U1, _U2>&& __in)
noexcept(__nothrow_assignable<_U1, _U2>())
{
this->_M_assign(std::move(__in));
return *this;
}
template<typename _U1, typename _U2>
_GLIBCXX20_CONSTEXPR
__enable_if_t<__assignable<const _U1&, const _U2&>(), tuple&>
operator=(const pair<_U1, _U2>& __in)
noexcept(__nothrow_assignable<const _U1&, const _U2&>())
{
this->_M_head(*this) = __in.first;
this->_M_tail(*this)._M_head(*this) = __in.second;
return *this;
}
template<typename _U1, typename _U2>
_GLIBCXX20_CONSTEXPR
__enable_if_t<__assignable<_U1, _U2>(), tuple&>
operator=(pair<_U1, _U2>&& __in)
noexcept(__nothrow_assignable<_U1, _U2>())
{
this->_M_head(*this) = std::forward<_U1>(__in.first);
this->_M_tail(*this)._M_head(*this) = std::forward<_U2>(__in.second);
return *this;
}
_GLIBCXX20_CONSTEXPR
void
swap(tuple& __in)
noexcept(__and_<__is_nothrow_swappable<_T1>,
__is_nothrow_swappable<_T2>>::value)
{ _Inherited::_M_swap(__in); }
};
/// class tuple_size
template<typename... _Elements>
struct tuple_size<tuple<_Elements...>>
: public integral_constant<size_t, sizeof...(_Elements)> { };
#if __cplusplus > 201402L
template <typename _Tp>
inline constexpr size_t tuple_size_v = tuple_size<_Tp>::value;
#endif
/**
* 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<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;
};
/**
* Error case for tuple_element: invalid index.
*/
template<size_t __i>
struct tuple_element<__i, tuple<>>
{
static_assert(__i < tuple_size<tuple<>>::value,
"tuple index must be in range");
};
template<size_t __i, typename _Head, typename... _Tail>
constexpr _Head&
__get_helper(_Tuple_impl<__i, _Head, _Tail...>& __t) noexcept
{ return _Tuple_impl<__i, _Head, _Tail...>::_M_head(__t); }
template<size_t __i, typename _Head, typename... _Tail>
constexpr const _Head&
__get_helper(const _Tuple_impl<__i, _Head, _Tail...>& __t) noexcept
{ return _Tuple_impl<__i, _Head, _Tail...>::_M_head(__t); }
// Deleted overload to improve diagnostics for invalid indices
template<size_t __i, typename... _Types>
__enable_if_t<(__i >= sizeof...(_Types))>
__get_helper(const tuple<_Types...>&) = delete;
/// Return a reference to the ith element of a tuple.
template<size_t __i, typename... _Elements>
constexpr __tuple_element_t<__i, tuple<_Elements...>>&
get(tuple<_Elements...>& __t) noexcept
{ return std::__get_helper<__i>(__t); }
/// Return a const reference to the ith element of a const tuple.
template<size_t __i, typename... _Elements>
constexpr const __tuple_element_t<__i, tuple<_Elements...>>&
get(const tuple<_Elements...>& __t) noexcept
{ return std::__get_helper<__i>(__t); }
/// Return an rvalue reference to the ith element of a tuple rvalue.
template<size_t __i, typename... _Elements>
constexpr __tuple_element_t<__i, tuple<_Elements...>>&&
get(tuple<_Elements...>&& __t) noexcept
{
typedef __tuple_element_t<__i, tuple<_Elements...>> __element_type;
return std::forward<__element_type>(std::__get_helper<__i>(__t));
}
/// Return a const rvalue reference to the ith element of a const tuple rvalue.
template<size_t __i, typename... _Elements>
constexpr const __tuple_element_t<__i, tuple<_Elements...>>&&
get(const tuple<_Elements...>&& __t) noexcept
{
typedef __tuple_element_t<__i, tuple<_Elements...>> __element_type;
return std::forward<const __element_type>(std::__get_helper<__i>(__t));
}
#if __cplusplus >= 201402L
#define __cpp_lib_tuples_by_type 201304
// Return the index of _Tp in _Types, if it occurs exactly once.
// Otherwise, return sizeof...(_Types).
// TODO reuse this for __detail::__variant::__exactly_once.
template<typename _Tp, typename... _Types>
constexpr size_t
__find_uniq_type_in_pack()
{
constexpr size_t __sz = sizeof...(_Types);
constexpr bool __found[__sz] = { __is_same(_Tp, _Types) ... };
size_t __n = __sz;
for (size_t __i = 0; __i < __sz; ++__i)
{
if (__found[__i])
{
if (__n < __sz) // more than one _Tp found
return __sz;
__n = __i;
}
}
return __n;
}
/// Return a reference to the unique element of type _Tp of a tuple.
template <typename _Tp, typename... _Types>
constexpr _Tp&
get(tuple<_Types...>& __t) noexcept
{
constexpr size_t __idx = __find_uniq_type_in_pack<_Tp, _Types...>();
static_assert(__idx < sizeof...(_Types),
"the type T in std::get<T> must occur exactly once in the tuple");
return std::__get_helper<__idx>(__t);
}
/// Return a reference to the unique element of type _Tp of a tuple rvalue.
template <typename _Tp, typename... _Types>
constexpr _Tp&&
get(tuple<_Types...>&& __t) noexcept
{
constexpr size_t __idx = __find_uniq_type_in_pack<_Tp, _Types...>();
static_assert(__idx < sizeof...(_Types),
"the type T in std::get<T> must occur exactly once in the tuple");
return std::forward<_Tp>(std::__get_helper<__idx>(__t));
}
/// Return a const reference to the unique element of type _Tp of a tuple.
template <typename _Tp, typename... _Types>
constexpr const _Tp&
get(const tuple<_Types...>& __t) noexcept
{
constexpr size_t __idx = __find_uniq_type_in_pack<_Tp, _Types...>();
static_assert(__idx < sizeof...(_Types),
"the type T in std::get<T> must occur exactly once in the tuple");
return std::__get_helper<__idx>(__t);
}
/// Return a const reference to the unique element of type _Tp of
/// a const tuple rvalue.
template <typename _Tp, typename... _Types>
constexpr const _Tp&&
get(const tuple<_Types...>&& __t) noexcept
{
constexpr size_t __idx = __find_uniq_type_in_pack<_Tp, _Types...>();
static_assert(__idx < sizeof...(_Types),
"the type T in std::get<T> must occur exactly once in the tuple");
return std::forward<const _Tp>(std::__get_helper<__idx>(__t));
}
#endif
// This class performs the comparison operations on tuples
template<typename _Tp, typename _Up, size_t __i, size_t __size>
struct __tuple_compare
{
static constexpr bool
__eq(const _Tp& __t, const _Up& __u)
{
return bool(std::get<__i>(__t) == std::get<__i>(__u))
&& __tuple_compare<_Tp, _Up, __i + 1, __size>::__eq(__t, __u);
}
static constexpr bool
__less(const _Tp& __t, const _Up& __u)
{
return bool(std::get<__i>(__t) < std::get<__i>(__u))
|| (!bool(std::get<__i>(__u) < std::get<__i>(__t))
&& __tuple_compare<_Tp, _Up, __i + 1, __size>::__less(__t, __u));
}
};
template<typename _Tp, typename _Up, size_t __size>
struct __tuple_compare<_Tp, _Up, __size, __size>
{
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)
{
static_assert(sizeof...(_TElements) == sizeof...(_UElements),
"tuple objects can only be compared if they have equal sizes.");
using __compare = __tuple_compare<tuple<_TElements...>,
tuple<_UElements...>,
0, sizeof...(_TElements)>;
return __compare::__eq(__t, __u);
}
#if __cpp_lib_three_way_comparison
template<typename _Cat, typename _Tp, typename _Up>
constexpr _Cat
__tuple_cmp(const _Tp&, const _Up&, index_sequence<>)
{ return _Cat::equivalent; }
template<typename _Cat, typename _Tp, typename _Up,
size_t _Idx0, size_t... _Idxs>
constexpr _Cat
__tuple_cmp(const _Tp& __t, const _Up& __u,
index_sequence<_Idx0, _Idxs...>)
{
auto __c
= __detail::__synth3way(std::get<_Idx0>(__t), std::get<_Idx0>(__u));
if (__c != 0)
return __c;
return std::__tuple_cmp<_Cat>(__t, __u, index_sequence<_Idxs...>());
}
template<typename... _Tps, typename... _Ups>
constexpr
common_comparison_category_t<__detail::__synth3way_t<_Tps, _Ups>...>
operator<=>(const tuple<_Tps...>& __t, const tuple<_Ups...>& __u)
{
using _Cat
= common_comparison_category_t<__detail::__synth3way_t<_Tps, _Ups>...>;
return std::__tuple_cmp<_Cat>(__t, __u, index_sequence_for<_Tps...>());
}
#else
template<typename... _TElements, typename... _UElements>
constexpr bool
operator<(const tuple<_TElements...>& __t,
const tuple<_UElements...>& __u)
{
static_assert(sizeof...(_TElements) == sizeof...(_UElements),
"tuple objects can only be compared if they have equal sizes.");
using __compare = __tuple_compare<tuple<_TElements...>,
tuple<_UElements...>,
0, sizeof...(_TElements)>;
return __compare::__less(__t, __u);
}
template<typename... _TElements, typename... _UElements>
constexpr bool
operator!=(const tuple<_TElements...>& __t,
const tuple<_UElements...>& __u)
{ return !(__t == __u); }
template<typename... _TElements, typename... _UElements>
constexpr bool
operator>(const tuple<_TElements...>& __t,
const tuple<_UElements...>& __u)
{ return __u < __t; }
template<typename... _TElements, typename... _UElements>
constexpr bool
operator<=(const tuple<_TElements...>& __t,
const tuple<_UElements...>& __u)
{ return !(__u < __t); }
template<typename... _TElements, typename... _UElements>
constexpr bool
operator>=(const tuple<_TElements...>& __t,
const tuple<_UElements...>& __u)
{ return !(__t < __u); }
#endif // three_way_comparison
// 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)...);
}
// _GLIBCXX_RESOLVE_LIB_DEFECTS
// 2275. Why is forward_as_tuple not constexpr?
/// std::forward_as_tuple
template<typename... _Elements>
constexpr tuple<_Elements&&...>
forward_as_tuple(_Elements&&... __args) noexcept
{ return tuple<_Elements&&...>(std::forward<_Elements>(__args)...); }
template<size_t, typename, typename, size_t>
struct __make_tuple_impl;
template<size_t _Idx, typename _Tuple, typename... _Tp, size_t _Nm>
struct __make_tuple_impl<_Idx, tuple<_Tp...>, _Tuple, _Nm>
: __make_tuple_impl<_Idx + 1,
tuple<_Tp..., __tuple_element_t<_Idx, _Tuple>>,
_Tuple, _Nm>
{ };
template<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
: __make_tuple_impl<0, tuple<>, _Tuple, tuple_size<_Tuple>::value>
{ };
// Returns the std::tuple equivalent of a tuple-like type.
template<typename _Tuple>
struct __make_tuple
: public __do_make_tuple<__remove_cvref_t<_Tuple>>
{ };
// 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 _Index_tuple<> __type;
};
template<typename _Tp, typename... _Tpls>
struct __make_1st_indices<_Tp, _Tpls...>
{
typedef typename _Build_index_tuple<tuple_size<
typename 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, size_t... _Is, typename _Tp, typename... _Tpls>
struct __tuple_concater<_Ret, _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, _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)...);
}
// _GLIBCXX_RESOLVE_LIB_DEFECTS
// 2301. Why is tie not constexpr?
/// tie
template<typename... _Elements>
constexpr tuple<_Elements&...>
tie(_Elements&... __args) noexcept
{ return tuple<_Elements&...>(__args...); }
/// swap
template<typename... _Elements>
_GLIBCXX20_CONSTEXPR
inline
#if __cplusplus > 201402L || !defined(__STRICT_ANSI__) // c++1z or gnu++11
// Constrained free swap overload, see p0185r1
typename enable_if<__and_<__is_swappable<_Elements>...>::value
>::type
#else
void
#endif
swap(tuple<_Elements...>& __x, tuple<_Elements...>& __y)
noexcept(noexcept(__x.swap(__y)))
{ __x.swap(__y); }
#if __cplusplus > 201402L || !defined(__STRICT_ANSI__) // c++1z or gnu++11
template<typename... _Elements>
_GLIBCXX20_CONSTEXPR
typename enable_if<!__and_<__is_swappable<_Elements>...>::value>::type
swap(tuple<_Elements...>&, tuple<_Elements...>&) = delete;
#endif
// A class (and instance) which can be used in 'tie' when an element
// of a tuple is not required.
// _GLIBCXX14_CONSTEXPR
// 2933. PR for LWG 2773 could be clearer
struct _Swallow_assign
{
template<class _Tp>
_GLIBCXX14_CONSTEXPR const _Swallow_assign&
operator=(const _Tp&) const
{ return *this; }
};
// _GLIBCXX_RESOLVE_LIB_DEFECTS
// 2773. Making std::ignore constexpr
_GLIBCXX17_INLINE constexpr _Swallow_assign ignore{};
/// Partial specialization for tuples
template<typename... _Types, typename _Alloc>
struct uses_allocator<tuple<_Types...>, _Alloc> : true_type { };
// See stl_pair.h...
/** "piecewise construction" using a tuple of arguments for each member.
*
* @param __first Arguments for the first member of the pair.
* @param __second Arguments for the second member of the pair.
*
* The elements of each tuple will be used as the constructor arguments
* for the data members of the pair.
*/
template<class _T1, class _T2>
template<typename... _Args1, typename... _Args2>
_GLIBCXX20_CONSTEXPR
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, size_t... _Indexes1,
typename... _Args2, size_t... _Indexes2>
_GLIBCXX20_CONSTEXPR 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))...)
{ }
#if __cplusplus >= 201703L
// Unpack a std::tuple into a type trait and use its value.
// For cv std::tuple<_Up> the result is _Trait<_Tp, cv _Up...>::value.
// For cv std::tuple<_Up>& the result is _Trait<_Tp, cv _Up&...>::value.
// Otherwise the result is false (because we don't know if std::get throws).
template<template<typename...> class _Trait, typename _Tp, typename _Tuple>
inline constexpr bool __unpack_std_tuple = false;
template<template<typename...> class _Trait, typename _Tp, typename... _Up>
inline constexpr bool __unpack_std_tuple<_Trait, _Tp, tuple<_Up...>>
= _Trait<_Tp, _Up...>::value;
template<template<typename...> class _Trait, typename _Tp, typename... _Up>
inline constexpr bool __unpack_std_tuple<_Trait, _Tp, tuple<_Up...>&>
= _Trait<_Tp, _Up&...>::value;
template<template<typename...> class _Trait, typename _Tp, typename... _Up>
inline constexpr bool __unpack_std_tuple<_Trait, _Tp, const tuple<_Up...>>
= _Trait<_Tp, const _Up...>::value;
template<template<typename...> class _Trait, typename _Tp, typename... _Up>
inline constexpr bool __unpack_std_tuple<_Trait, _Tp, const tuple<_Up...>&>
= _Trait<_Tp, const _Up&...>::value;
# define __cpp_lib_apply 201603
template <typename _Fn, typename _Tuple, size_t... _Idx>
constexpr decltype(auto)
__apply_impl(_Fn&& __f, _Tuple&& __t, index_sequence<_Idx...>)
{
return std::__invoke(std::forward<_Fn>(__f),
std::get<_Idx>(std::forward<_Tuple>(__t))...);
}
template <typename _Fn, typename _Tuple>
constexpr decltype(auto)
apply(_Fn&& __f, _Tuple&& __t)
noexcept(__unpack_std_tuple<is_nothrow_invocable, _Fn, _Tuple>)
{
using _Indices
= make_index_sequence<tuple_size_v<remove_reference_t<_Tuple>>>;
return std::__apply_impl(std::forward<_Fn>(__f),
std::forward<_Tuple>(__t),
_Indices{});
}
#define __cpp_lib_make_from_tuple 201606
template <typename _Tp, typename _Tuple, size_t... _Idx>
constexpr _Tp
__make_from_tuple_impl(_Tuple&& __t, index_sequence<_Idx...>)
{ return _Tp(std::get<_Idx>(std::forward<_Tuple>(__t))...); }
template <typename _Tp, typename _Tuple>
constexpr _Tp
make_from_tuple(_Tuple&& __t)
noexcept(__unpack_std_tuple<is_nothrow_constructible, _Tp, _Tuple>)
{
return __make_from_tuple_impl<_Tp>(
std::forward<_Tuple>(__t),
make_index_sequence<tuple_size_v<remove_reference_t<_Tuple>>>{});
}
#endif // C++17
/// @}
_GLIBCXX_END_NAMESPACE_VERSION
} // namespace std
#endif // C++11
#endif // _GLIBCXX_TUPLE