include/__tuple

// -*- C++ -*-
//===----------------------------------------------------------------------===//
//
//                     The LLVM Compiler Infrastructure
//
// This file is dual licensed under the MIT and the University of Illinois Open
// Source Licenses. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//

#ifndef _LIBCPP___TUPLE
#define _LIBCPP___TUPLE

#include <__config>
#include <cstddef>
#include <type_traits>

#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
#pragma GCC system_header
#endif


_LIBCPP_BEGIN_NAMESPACE_STD

template <class _Tp> class _LIBCPP_TYPE_VIS_ONLY tuple_size;

template <class _Tp>
class _LIBCPP_TYPE_VIS_ONLY tuple_size<const _Tp>
    : public tuple_size<_Tp> {};

template <class _Tp>
class _LIBCPP_TYPE_VIS_ONLY tuple_size<volatile _Tp>
    : public tuple_size<_Tp> {};

template <class _Tp>
class _LIBCPP_TYPE_VIS_ONLY tuple_size<const volatile _Tp>
    : public tuple_size<_Tp> {};

template <size_t _Ip, class _Tp> class _LIBCPP_TYPE_VIS_ONLY tuple_element;

template <size_t _Ip, class _Tp>
class _LIBCPP_TYPE_VIS_ONLY tuple_element<_Ip, const _Tp>
{
public:
    typedef typename add_const<typename tuple_element<_Ip, _Tp>::type>::type type;
};

template <size_t _Ip, class _Tp>
class _LIBCPP_TYPE_VIS_ONLY tuple_element<_Ip, volatile _Tp>
{
public:
    typedef typename add_volatile<typename tuple_element<_Ip, _Tp>::type>::type type;
};

template <size_t _Ip, class _Tp>
class _LIBCPP_TYPE_VIS_ONLY tuple_element<_Ip, const volatile _Tp>
{
public:
    typedef typename add_cv<typename tuple_element<_Ip, _Tp>::type>::type type;
};

template <class _Tp> struct __tuple_like : false_type {};

template <class _Tp> struct __tuple_like<const _Tp> : public __tuple_like<_Tp> {};
template <class _Tp> struct __tuple_like<volatile _Tp> : public __tuple_like<_Tp> {};
template <class _Tp> struct __tuple_like<const volatile _Tp> : public __tuple_like<_Tp> {};

// tuple specializations

#if !defined(_LIBCPP_HAS_NO_VARIADICS)

template <size_t...> struct __tuple_indices {};

template <class _IdxType, _IdxType... _Values>
struct __integer_sequence {
  template <template <class _OIdxType, _OIdxType...> class _ToIndexSeq, class _ToIndexType>
  using __convert = _ToIndexSeq<_ToIndexType, _Values...>;

  template <size_t _Sp>
  using __to_tuple_indices = __tuple_indices<(_Values + _Sp)...>;
};

#if !__has_builtin(__make_integer_seq) || defined(_LIBCPP_TESTING_FALLBACK_MAKE_INTEGER_SEQUENCE)
namespace __detail {

template<typename _Tp, size_t ..._Extra> struct __repeat;
template<typename _Tp, _Tp ..._Np, size_t ..._Extra> struct __repeat<__integer_sequence<_Tp, _Np...>, _Extra...> {
  typedef __integer_sequence<_Tp,
                           _Np...,
                           sizeof...(_Np) + _Np...,
                           2 * sizeof...(_Np) + _Np...,
                           3 * sizeof...(_Np) + _Np...,
                           4 * sizeof...(_Np) + _Np...,
                           5 * sizeof...(_Np) + _Np...,
                           6 * sizeof...(_Np) + _Np...,
                           7 * sizeof...(_Np) + _Np...,
                           _Extra...> type;
};

template<size_t _Np> struct __parity;
template<size_t _Np> struct __make : __parity<_Np % 8>::template __pmake<_Np> {};

template<> struct __make<0> { typedef __integer_sequence<size_t> type; };
template<> struct __make<1> { typedef __integer_sequence<size_t, 0> type; };
template<> struct __make<2> { typedef __integer_sequence<size_t, 0, 1> type; };
template<> struct __make<3> { typedef __integer_sequence<size_t, 0, 1, 2> type; };
template<> struct __make<4> { typedef __integer_sequence<size_t, 0, 1, 2, 3> type; };
template<> struct __make<5> { typedef __integer_sequence<size_t, 0, 1, 2, 3, 4> type; };
template<> struct __make<6> { typedef __integer_sequence<size_t, 0, 1, 2, 3, 4, 5> type; };
template<> struct __make<7> { typedef __integer_sequence<size_t, 0, 1, 2, 3, 4, 5, 6> type; };

template<> struct __parity<0> { template<size_t _Np> struct __pmake : __repeat<typename __make<_Np / 8>::type> {}; };
template<> struct __parity<1> { template<size_t _Np> struct __pmake : __repeat<typename __make<_Np / 8>::type, _Np - 1> {}; };
template<> struct __parity<2> { template<size_t _Np> struct __pmake : __repeat<typename __make<_Np / 8>::type, _Np - 2, _Np - 1> {}; };
template<> struct __parity<3> { template<size_t _Np> struct __pmake : __repeat<typename __make<_Np / 8>::type, _Np - 3, _Np - 2, _Np - 1> {}; };
template<> struct __parity<4> { template<size_t _Np> struct __pmake : __repeat<typename __make<_Np / 8>::type, _Np - 4, _Np - 3, _Np - 2, _Np - 1> {}; };
template<> struct __parity<5> { template<size_t _Np> struct __pmake : __repeat<typename __make<_Np / 8>::type, _Np - 5, _Np - 4, _Np - 3, _Np - 2, _Np - 1> {}; };
template<> struct __parity<6> { template<size_t _Np> struct __pmake : __repeat<typename __make<_Np / 8>::type, _Np - 6, _Np - 5, _Np - 4, _Np - 3, _Np - 2, _Np - 1> {}; };
template<> struct __parity<7> { template<size_t _Np> struct __pmake : __repeat<typename __make<_Np / 8>::type, _Np - 7, _Np - 6, _Np - 5, _Np - 4, _Np - 3, _Np - 2, _Np - 1> {}; };

} // namespace detail

#endif  // !__has_builtin(__make_integer_seq) || defined(_LIBCPP_TESTING_FALLBACK_MAKE_INTEGER_SEQUENCE)

#if __has_builtin(__make_integer_seq)
template <size_t _Ep, size_t _Sp>
using __make_indices_imp =
    typename __make_integer_seq<__integer_sequence, size_t, _Ep - _Sp>::template
    __to_tuple_indices<_Sp>;
#else
template <size_t _Ep, size_t _Sp>
using __make_indices_imp =
    typename __detail::__make<_Ep - _Sp>::type::template __to_tuple_indices<_Sp>;

#endif

template <size_t _Ep, size_t _Sp = 0>
struct __make_tuple_indices
{
    static_assert(_Sp <= _Ep, "__make_tuple_indices input error");
    typedef __make_indices_imp<_Ep, _Sp> type;
};


template <class ..._Tp> class _LIBCPP_TYPE_VIS_ONLY tuple;

template <class... _Tp> struct __tuple_like<tuple<_Tp...> > : true_type {};

template <size_t _Ip, class ..._Tp>
_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
typename tuple_element<_Ip, tuple<_Tp...> >::type&
get(tuple<_Tp...>&) _NOEXCEPT;

template <size_t _Ip, class ..._Tp>
_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
const typename tuple_element<_Ip, tuple<_Tp...> >::type&
get(const tuple<_Tp...>&) _NOEXCEPT;

template <size_t _Ip, class ..._Tp>
_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
typename tuple_element<_Ip, tuple<_Tp...> >::type&&
get(tuple<_Tp...>&&) _NOEXCEPT;

template <size_t _Ip, class ..._Tp>
_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
const typename tuple_element<_Ip, tuple<_Tp...> >::type&&
get(const tuple<_Tp...>&&) _NOEXCEPT;
#endif

// pair specializations

template <class _T1, class _T2> struct __tuple_like<pair<_T1, _T2> > : true_type {};

template <size_t _Ip, class _T1, class _T2>
_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
typename tuple_element<_Ip, pair<_T1, _T2> >::type&
get(pair<_T1, _T2>&) _NOEXCEPT;

template <size_t _Ip, class _T1, class _T2>
_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
const typename tuple_element<_Ip, pair<_T1, _T2> >::type&
get(const pair<_T1, _T2>&) _NOEXCEPT;

#if !defined(_LIBCPP_HAS_NO_RVALUE_REFERENCES)
template <size_t _Ip, class _T1, class _T2>
_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
typename tuple_element<_Ip, pair<_T1, _T2> >::type&&
get(pair<_T1, _T2>&&) _NOEXCEPT;

template <size_t _Ip, class _T1, class _T2>
_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
const typename tuple_element<_Ip, pair<_T1, _T2> >::type&&
get(const pair<_T1, _T2>&&) _NOEXCEPT;
#endif

// array specializations

template <class _Tp, size_t _Size> struct _LIBCPP_TYPE_VIS_ONLY array;

template <class _Tp, size_t _Size> struct __tuple_like<array<_Tp, _Size> > : true_type {};

template <size_t _Ip, class _Tp, size_t _Size>
_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
_Tp&
get(array<_Tp, _Size>&) _NOEXCEPT;

template <size_t _Ip, class _Tp, size_t _Size>
_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
const _Tp&
get(const array<_Tp, _Size>&) _NOEXCEPT;

#if !defined(_LIBCPP_HAS_NO_RVALUE_REFERENCES)
template <size_t _Ip, class _Tp, size_t _Size>
_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
_Tp&&
get(array<_Tp, _Size>&&) _NOEXCEPT;

template <size_t _Ip, class _Tp, size_t _Size>
_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
const _Tp&&
get(const array<_Tp, _Size>&&) _NOEXCEPT;
#endif

#if !defined(_LIBCPP_HAS_NO_VARIADICS)


// __tuple_types

template <class ..._Tp> struct __tuple_types {};

template <size_t _Ip>
class _LIBCPP_TYPE_VIS_ONLY tuple_element<_Ip, __tuple_types<> >
{
public:
    static_assert(_Ip == 0, "tuple_element index out of range");
    static_assert(_Ip != 0, "tuple_element index out of range");
};

template <class _Hp, class ..._Tp>
class _LIBCPP_TYPE_VIS_ONLY tuple_element<0, __tuple_types<_Hp, _Tp...> >
{
public:
    typedef _Hp type;
};

template <size_t _Ip, class _Hp, class ..._Tp>
class _LIBCPP_TYPE_VIS_ONLY tuple_element<_Ip, __tuple_types<_Hp, _Tp...> >
{
public:
    typedef typename tuple_element<_Ip-1, __tuple_types<_Tp...> >::type type;
};

template <class ..._Tp>
class _LIBCPP_TYPE_VIS_ONLY tuple_size<__tuple_types<_Tp...> >
    : public integral_constant<size_t, sizeof...(_Tp)>
{
};

template <class... _Tp> struct __tuple_like<__tuple_types<_Tp...> > : true_type {};

// __make_tuple_types

// __make_tuple_types<_Tuple<_Types...>, _Ep, _Sp>::type is a
// __tuple_types<_Types...> using only those _Types in the range [_Sp, _Ep).
// _Sp defaults to 0 and _Ep defaults to tuple_size<_Tuple>.  If _Tuple is a
// lvalue_reference type, then __tuple_types<_Types&...> is the result.

template <class _TupleTypes, class _Tp, size_t _Sp, size_t _Ep>
struct __make_tuple_types_imp;

template <class ..._Types, class _Tp, size_t _Sp, size_t _Ep>
struct __make_tuple_types_imp<__tuple_types<_Types...>, _Tp, _Sp, _Ep>
{
    typedef typename remove_reference<_Tp>::type _Tpr;
    typedef typename __make_tuple_types_imp<__tuple_types<_Types...,
                                            typename conditional<is_lvalue_reference<_Tp>::value,
                                                typename tuple_element<_Sp, _Tpr>::type&,
                                                typename tuple_element<_Sp, _Tpr>::type>::type>,
                                            _Tp, _Sp+1, _Ep>::type type;
};

template <class ..._Types, class _Tp, size_t _Ep>
struct __make_tuple_types_imp<__tuple_types<_Types...>, _Tp, _Ep, _Ep>
{
    typedef __tuple_types<_Types...> type;
};

template <class _Tp, size_t _Ep = tuple_size<typename remove_reference<_Tp>::type>::value, size_t _Sp = 0>
struct __make_tuple_types
{
    static_assert(_Sp <= _Ep, "__make_tuple_types input error");
    typedef typename __make_tuple_types_imp<__tuple_types<>, _Tp, _Sp, _Ep>::type type;
};

// __tuple_convertible

template <class, class>
struct __tuple_convertible_imp : public false_type {};

template <class _Tp0, class ..._Tp, class _Up0, class ..._Up>
struct __tuple_convertible_imp<__tuple_types<_Tp0, _Tp...>, __tuple_types<_Up0, _Up...> >
    : public integral_constant<bool,
                               is_convertible<_Tp0, _Up0>::value &&
                               __tuple_convertible_imp<__tuple_types<_Tp...>, __tuple_types<_Up...> >::value> {};

template <>
struct __tuple_convertible_imp<__tuple_types<>, __tuple_types<> >
    : public true_type {};

template <bool, class, class>
struct __tuple_convertible_apply : public false_type {};

template <class _Tp, class _Up>
struct __tuple_convertible_apply<true, _Tp, _Up>
  : public __tuple_convertible_imp<
      typename __make_tuple_types<_Tp>::type
    , typename __make_tuple_types<_Up>::type
    >
{};

template <class _Tp, class _Up, bool = __tuple_like<typename remove_reference<_Tp>::type>::value,
                                bool = __tuple_like<_Up>::value>
struct __tuple_convertible
    : public false_type {};

template <class _Tp, class _Up>
struct __tuple_convertible<_Tp, _Up, true, true>
    : public __tuple_convertible_apply<tuple_size<typename remove_reference<_Tp>::type>::value ==
                                     tuple_size<_Up>::value, _Tp, _Up>
{};

// __tuple_constructible

template <class, class>
struct __tuple_constructible_imp : public false_type {};

template <class _Tp0, class ..._Tp, class _Up0, class ..._Up>
struct __tuple_constructible_imp<__tuple_types<_Tp0, _Tp...>, __tuple_types<_Up0, _Up...> >
    : public integral_constant<bool,
                               is_constructible<_Up0, _Tp0>::value &&
                               __tuple_constructible_imp<__tuple_types<_Tp...>, __tuple_types<_Up...> >::value> {};

template <>
struct __tuple_constructible_imp<__tuple_types<>, __tuple_types<> >
    : public true_type {};

template <bool _SameSize, class, class>
struct __tuple_constructible_apply : public false_type {};

template <class _Tp, class _Up>
struct __tuple_constructible_apply<true, _Tp, _Up>
  : public __tuple_constructible_imp<
      typename __make_tuple_types<_Tp>::type
    , typename __make_tuple_types<_Up>::type
    >
{};

template <class _Tp, class _Up, bool = __tuple_like<typename remove_reference<_Tp>::type>::value,
                                bool = __tuple_like<_Up>::value>
struct __tuple_constructible
    : public false_type {};

template <class _Tp, class _Up>
struct __tuple_constructible<_Tp, _Up, true, true>
    : public __tuple_constructible_apply<tuple_size<typename remove_reference<_Tp>::type>::value ==
                                     tuple_size<_Up>::value, _Tp, _Up>
{};

// __tuple_assignable

template <class, class>
struct __tuple_assignable_imp : public false_type {};

template <class _Tp0, class ..._Tp, class _Up0, class ..._Up>
struct __tuple_assignable_imp<__tuple_types<_Tp0, _Tp...>, __tuple_types<_Up0, _Up...> >
    : public integral_constant<bool,
                               is_assignable<_Up0&, _Tp0>::value &&
                               __tuple_assignable_imp<__tuple_types<_Tp...>, __tuple_types<_Up...> >::value> {};

template <>
struct __tuple_assignable_imp<__tuple_types<>, __tuple_types<> >
    : public true_type {};

template <bool, class, class>
struct __tuple_assignable_apply : public false_type {};

template <class _Tp, class _Up>
struct __tuple_assignable_apply<true, _Tp, _Up>
  : __tuple_assignable_imp<
      typename __make_tuple_types<_Tp>::type
    , typename __make_tuple_types<_Up>::type
    >
{};

template <class _Tp, class _Up, bool = __tuple_like<typename remove_reference<_Tp>::type>::value,
                                bool = __tuple_like<_Up>::value>
struct __tuple_assignable
    : public false_type {};

template <class _Tp, class _Up>
struct __tuple_assignable<_Tp, _Up, true, true>
    : public __tuple_assignable_apply<tuple_size<typename remove_reference<_Tp>::type>::value ==
                                    tuple_size<_Up>::value, _Tp, _Up>
{};

#endif  // _LIBCPP_HAS_NO_VARIADICS

_LIBCPP_END_NAMESPACE_STD

#endif  // _LIBCPP___TUPLE