1// -*- C++ -*- 2//===----------------------------------------------------------------------===// 3// 4// The LLVM Compiler Infrastructure 5// 6// This file is dual licensed under the MIT and the University of Illinois Open 7// Source Licenses. See LICENSE.TXT for details. 8// 9//===----------------------------------------------------------------------===// 10 11#ifndef _LIBCPP___TUPLE 12#define _LIBCPP___TUPLE 13 14#include <__config> 15#include <cstddef> 16#include <type_traits> 17 18#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER) 19#pragma GCC system_header 20#endif 21 22 23_LIBCPP_BEGIN_NAMESPACE_STD 24 25template <class _Tp> class _LIBCPP_TYPE_VIS_ONLY tuple_size; 26 27struct __empty_tuple_size_base {}; 28 29template <class _Tp, class = void> 30struct __tuple_size_base_type { 31 typedef __empty_tuple_size_base type; 32}; 33 34template <class _Tp> 35struct __tuple_size_base_type<_Tp, typename __void_t<decltype(tuple_size<_Tp>::value)>::type> 36{ 37 typedef integral_constant<size_t, tuple_size<_Tp>::value> type; 38}; 39 40template <class _Tp> 41class _LIBCPP_TYPE_VIS_ONLY tuple_size<const _Tp> 42 : public __tuple_size_base_type<_Tp>::type {}; 43 44template <class _Tp> 45class _LIBCPP_TYPE_VIS_ONLY tuple_size<volatile _Tp> 46 : public __tuple_size_base_type<_Tp>::type {}; 47 48template <class _Tp> 49class _LIBCPP_TYPE_VIS_ONLY tuple_size<const volatile _Tp> 50 : public __tuple_size_base_type<_Tp>::type {}; 51 52template <size_t _Ip, class _Tp> class _LIBCPP_TYPE_VIS_ONLY tuple_element; 53 54template <size_t _Ip, class _Tp> 55class _LIBCPP_TYPE_VIS_ONLY tuple_element<_Ip, const _Tp> 56{ 57public: 58 typedef typename add_const<typename tuple_element<_Ip, _Tp>::type>::type type; 59}; 60 61template <size_t _Ip, class _Tp> 62class _LIBCPP_TYPE_VIS_ONLY tuple_element<_Ip, volatile _Tp> 63{ 64public: 65 typedef typename add_volatile<typename tuple_element<_Ip, _Tp>::type>::type type; 66}; 67 68template <size_t _Ip, class _Tp> 69class _LIBCPP_TYPE_VIS_ONLY tuple_element<_Ip, const volatile _Tp> 70{ 71public: 72 typedef typename add_cv<typename tuple_element<_Ip, _Tp>::type>::type type; 73}; 74 75template <class _Tp> struct __tuple_like : false_type {}; 76 77template <class _Tp> struct __tuple_like<const _Tp> : public __tuple_like<_Tp> {}; 78template <class _Tp> struct __tuple_like<volatile _Tp> : public __tuple_like<_Tp> {}; 79template <class _Tp> struct __tuple_like<const volatile _Tp> : public __tuple_like<_Tp> {}; 80 81// tuple specializations 82 83#if !defined(_LIBCPP_HAS_NO_VARIADICS) 84 85template <size_t...> struct __tuple_indices {}; 86 87template <class _IdxType, _IdxType... _Values> 88struct __integer_sequence { 89 template <template <class _OIdxType, _OIdxType...> class _ToIndexSeq, class _ToIndexType> 90 using __convert = _ToIndexSeq<_ToIndexType, _Values...>; 91 92 template <size_t _Sp> 93 using __to_tuple_indices = __tuple_indices<(_Values + _Sp)...>; 94}; 95 96#if !__has_builtin(__make_integer_seq) || defined(_LIBCPP_TESTING_FALLBACK_MAKE_INTEGER_SEQUENCE) 97namespace __detail { 98 99template<typename _Tp, size_t ..._Extra> struct __repeat; 100template<typename _Tp, _Tp ..._Np, size_t ..._Extra> struct __repeat<__integer_sequence<_Tp, _Np...>, _Extra...> { 101 typedef __integer_sequence<_Tp, 102 _Np..., 103 sizeof...(_Np) + _Np..., 104 2 * sizeof...(_Np) + _Np..., 105 3 * sizeof...(_Np) + _Np..., 106 4 * sizeof...(_Np) + _Np..., 107 5 * sizeof...(_Np) + _Np..., 108 6 * sizeof...(_Np) + _Np..., 109 7 * sizeof...(_Np) + _Np..., 110 _Extra...> type; 111}; 112 113template<size_t _Np> struct __parity; 114template<size_t _Np> struct __make : __parity<_Np % 8>::template __pmake<_Np> {}; 115 116template<> struct __make<0> { typedef __integer_sequence<size_t> type; }; 117template<> struct __make<1> { typedef __integer_sequence<size_t, 0> type; }; 118template<> struct __make<2> { typedef __integer_sequence<size_t, 0, 1> type; }; 119template<> struct __make<3> { typedef __integer_sequence<size_t, 0, 1, 2> type; }; 120template<> struct __make<4> { typedef __integer_sequence<size_t, 0, 1, 2, 3> type; }; 121template<> struct __make<5> { typedef __integer_sequence<size_t, 0, 1, 2, 3, 4> type; }; 122template<> struct __make<6> { typedef __integer_sequence<size_t, 0, 1, 2, 3, 4, 5> type; }; 123template<> struct __make<7> { typedef __integer_sequence<size_t, 0, 1, 2, 3, 4, 5, 6> type; }; 124 125template<> struct __parity<0> { template<size_t _Np> struct __pmake : __repeat<typename __make<_Np / 8>::type> {}; }; 126template<> struct __parity<1> { template<size_t _Np> struct __pmake : __repeat<typename __make<_Np / 8>::type, _Np - 1> {}; }; 127template<> struct __parity<2> { template<size_t _Np> struct __pmake : __repeat<typename __make<_Np / 8>::type, _Np - 2, _Np - 1> {}; }; 128template<> struct __parity<3> { template<size_t _Np> struct __pmake : __repeat<typename __make<_Np / 8>::type, _Np - 3, _Np - 2, _Np - 1> {}; }; 129template<> struct __parity<4> { template<size_t _Np> struct __pmake : __repeat<typename __make<_Np / 8>::type, _Np - 4, _Np - 3, _Np - 2, _Np - 1> {}; }; 130template<> 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> {}; }; 131template<> 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> {}; }; 132template<> 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> {}; }; 133 134} // namespace detail 135 136#endif // !__has_builtin(__make_integer_seq) || defined(_LIBCPP_TESTING_FALLBACK_MAKE_INTEGER_SEQUENCE) 137 138#if __has_builtin(__make_integer_seq) 139template <size_t _Ep, size_t _Sp> 140using __make_indices_imp = 141 typename __make_integer_seq<__integer_sequence, size_t, _Ep - _Sp>::template 142 __to_tuple_indices<_Sp>; 143#else 144template <size_t _Ep, size_t _Sp> 145using __make_indices_imp = 146 typename __detail::__make<_Ep - _Sp>::type::template __to_tuple_indices<_Sp>; 147 148#endif 149 150template <size_t _Ep, size_t _Sp = 0> 151struct __make_tuple_indices 152{ 153 static_assert(_Sp <= _Ep, "__make_tuple_indices input error"); 154 typedef __make_indices_imp<_Ep, _Sp> type; 155}; 156 157 158template <class ..._Tp> class _LIBCPP_TYPE_VIS_ONLY tuple; 159 160template <class... _Tp> struct __tuple_like<tuple<_Tp...> > : true_type {}; 161 162template <class ..._Tp> 163class _LIBCPP_TYPE_VIS_ONLY tuple_size<tuple<_Tp...> > 164 : public integral_constant<size_t, sizeof...(_Tp)> 165{ 166}; 167 168template <size_t _Ip, class ..._Tp> 169_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11 170typename tuple_element<_Ip, tuple<_Tp...> >::type& 171get(tuple<_Tp...>&) _NOEXCEPT; 172 173template <size_t _Ip, class ..._Tp> 174_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11 175const typename tuple_element<_Ip, tuple<_Tp...> >::type& 176get(const tuple<_Tp...>&) _NOEXCEPT; 177 178template <size_t _Ip, class ..._Tp> 179_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11 180typename tuple_element<_Ip, tuple<_Tp...> >::type&& 181get(tuple<_Tp...>&&) _NOEXCEPT; 182 183template <size_t _Ip, class ..._Tp> 184_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11 185const typename tuple_element<_Ip, tuple<_Tp...> >::type&& 186get(const tuple<_Tp...>&&) _NOEXCEPT; 187#endif 188 189// pair specializations 190 191template <class _T1, class _T2> struct __tuple_like<pair<_T1, _T2> > : true_type {}; 192 193template <size_t _Ip, class _T1, class _T2> 194_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11 195typename tuple_element<_Ip, pair<_T1, _T2> >::type& 196get(pair<_T1, _T2>&) _NOEXCEPT; 197 198template <size_t _Ip, class _T1, class _T2> 199_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11 200const typename tuple_element<_Ip, pair<_T1, _T2> >::type& 201get(const pair<_T1, _T2>&) _NOEXCEPT; 202 203#if !defined(_LIBCPP_HAS_NO_RVALUE_REFERENCES) 204template <size_t _Ip, class _T1, class _T2> 205_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11 206typename tuple_element<_Ip, pair<_T1, _T2> >::type&& 207get(pair<_T1, _T2>&&) _NOEXCEPT; 208 209template <size_t _Ip, class _T1, class _T2> 210_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11 211const typename tuple_element<_Ip, pair<_T1, _T2> >::type&& 212get(const pair<_T1, _T2>&&) _NOEXCEPT; 213#endif 214 215// array specializations 216 217template <class _Tp, size_t _Size> struct _LIBCPP_TYPE_VIS_ONLY array; 218 219template <class _Tp, size_t _Size> struct __tuple_like<array<_Tp, _Size> > : true_type {}; 220 221template <size_t _Ip, class _Tp, size_t _Size> 222_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11 223_Tp& 224get(array<_Tp, _Size>&) _NOEXCEPT; 225 226template <size_t _Ip, class _Tp, size_t _Size> 227_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11 228const _Tp& 229get(const array<_Tp, _Size>&) _NOEXCEPT; 230 231#if !defined(_LIBCPP_HAS_NO_RVALUE_REFERENCES) 232template <size_t _Ip, class _Tp, size_t _Size> 233_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11 234_Tp&& 235get(array<_Tp, _Size>&&) _NOEXCEPT; 236 237template <size_t _Ip, class _Tp, size_t _Size> 238_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11 239const _Tp&& 240get(const array<_Tp, _Size>&&) _NOEXCEPT; 241#endif 242 243#if !defined(_LIBCPP_HAS_NO_VARIADICS) 244 245 246// __tuple_types 247 248template <class ..._Tp> struct __tuple_types {}; 249 250#if !__has_builtin(__type_pack_element) 251 252namespace __indexer_detail { 253 254template <size_t _Idx, class _Tp> 255struct __indexed { using type = _Tp; }; 256 257template <class _Types, class _Indexes> struct __indexer; 258 259template <class ..._Types, size_t ..._Idx> 260struct __indexer<__tuple_types<_Types...>, __tuple_indices<_Idx...>> 261 : __indexed<_Idx, _Types>... 262{}; 263 264template <size_t _Idx, class _Tp> 265__indexed<_Idx, _Tp> __at_index(__indexed<_Idx, _Tp> const&); 266 267} // namespace __indexer_detail 268 269template <size_t _Idx, class ..._Types> 270using __type_pack_element = typename decltype( 271 __indexer_detail::__at_index<_Idx>( 272 __indexer_detail::__indexer< 273 __tuple_types<_Types...>, 274 typename __make_tuple_indices<sizeof...(_Types)>::type 275 >{}) 276 )::type; 277#endif 278 279template <size_t _Ip, class ..._Types> 280class _LIBCPP_TYPE_VIS_ONLY tuple_element<_Ip, __tuple_types<_Types...>> 281{ 282public: 283 static_assert(_Ip < sizeof...(_Types), "tuple_element index out of range"); 284 typedef __type_pack_element<_Ip, _Types...> type; 285}; 286 287 288template <class ..._Tp> 289class _LIBCPP_TYPE_VIS_ONLY tuple_size<__tuple_types<_Tp...> > 290 : public integral_constant<size_t, sizeof...(_Tp)> 291{ 292}; 293 294template <class... _Tp> struct __tuple_like<__tuple_types<_Tp...> > : true_type {}; 295 296template <bool _ApplyLV, bool _ApplyConst, bool _ApplyVolatile> 297struct __apply_cv_mf; 298template <> 299struct __apply_cv_mf<false, false, false> { 300 template <class _Tp> using __apply = _Tp; 301}; 302template <> 303struct __apply_cv_mf<false, true, false> { 304 template <class _Tp> using __apply = const _Tp; 305}; 306template <> 307struct __apply_cv_mf<false, false, true> { 308 template <class _Tp> using __apply = volatile _Tp; 309}; 310template <> 311struct __apply_cv_mf<false, true, true> { 312 template <class _Tp> using __apply = const volatile _Tp; 313}; 314template <> 315struct __apply_cv_mf<true, false, false> { 316 template <class _Tp> using __apply = _Tp&; 317}; 318template <> 319struct __apply_cv_mf<true, true, false> { 320 template <class _Tp> using __apply = const _Tp&; 321}; 322template <> 323struct __apply_cv_mf<true, false, true> { 324 template <class _Tp> using __apply = volatile _Tp&; 325}; 326template <> 327struct __apply_cv_mf<true, true, true> { 328 template <class _Tp> using __apply = const volatile _Tp&; 329}; 330template <class _Tp, class _RawTp = typename remove_reference<_Tp>::type> 331using __apply_cv_t = __apply_cv_mf< 332 is_lvalue_reference<_Tp>::value, 333 is_const<_RawTp>::value, 334 is_volatile<_RawTp>::value>; 335 336// __make_tuple_types 337 338// __make_tuple_types<_Tuple<_Types...>, _Ep, _Sp>::type is a 339// __tuple_types<_Types...> using only those _Types in the range [_Sp, _Ep). 340// _Sp defaults to 0 and _Ep defaults to tuple_size<_Tuple>. If _Tuple is a 341// lvalue_reference type, then __tuple_types<_Types&...> is the result. 342 343template <class _TupleTypes, class _TupleIndices> 344struct __make_tuple_types_flat; 345 346template <template <class...> class _Tuple, class ..._Types, size_t ..._Idx> 347struct __make_tuple_types_flat<_Tuple<_Types...>, __tuple_indices<_Idx...>> { 348 // Specialization for pair, tuple, and __tuple_types 349 template <class _Tp, class _ApplyFn = __apply_cv_t<_Tp>> 350 using __apply_quals = __tuple_types< 351 typename _ApplyFn::template __apply<__type_pack_element<_Idx, _Types...>>... 352 >; 353}; 354 355template <class _Vt, size_t _Np, size_t ..._Idx> 356struct __make_tuple_types_flat<array<_Vt, _Np>, __tuple_indices<_Idx...>> { 357 template <size_t> 358 using __value_type = _Vt; 359 template <class _Tp, class _ApplyFn = __apply_cv_t<_Tp>> 360 using __apply_quals = __tuple_types< 361 typename _ApplyFn::template __apply<__value_type<_Idx>>... 362 >; 363}; 364 365template <class _Tp, size_t _Ep = tuple_size<typename remove_reference<_Tp>::type>::value, 366 size_t _Sp = 0, 367 bool _SameSize = (_Ep == tuple_size<typename remove_reference<_Tp>::type>::value)> 368struct __make_tuple_types 369{ 370 static_assert(_Sp <= _Ep, "__make_tuple_types input error"); 371 using _RawTp = typename remove_cv<typename remove_reference<_Tp>::type>::type; 372 using _Maker = __make_tuple_types_flat<_RawTp, typename __make_tuple_indices<_Ep, _Sp>::type>; 373 using type = typename _Maker::template __apply_quals<_Tp>; 374}; 375 376template <class ..._Types, size_t _Ep> 377struct __make_tuple_types<tuple<_Types...>, _Ep, 0, true> { 378 typedef __tuple_types<_Types...> type; 379}; 380 381template <class ..._Types, size_t _Ep> 382struct __make_tuple_types<__tuple_types<_Types...>, _Ep, 0, true> { 383 typedef __tuple_types<_Types...> type; 384}; 385 386template <bool ..._Preds> 387struct __all_dummy; 388 389template <bool ..._Pred> 390using __all = is_same<__all_dummy<_Pred...>, __all_dummy<((void)_Pred, true)...>>; 391 392struct __tuple_sfinae_base { 393 template <template <class, class...> class _Trait, 394 class ..._LArgs, class ..._RArgs> 395 static auto __do_test(__tuple_types<_LArgs...>, __tuple_types<_RArgs...>) 396 -> __all<typename enable_if<_Trait<_LArgs, _RArgs>::value, bool>::type{true}...>; 397 template <template <class...> class> 398 static auto __do_test(...) -> false_type; 399 400 template <class _FromArgs, class _ToArgs> 401 using __constructible = decltype(__do_test<is_constructible>(_ToArgs{}, _FromArgs{})); 402 template <class _FromArgs, class _ToArgs> 403 using __convertible = decltype(__do_test<is_convertible>(_FromArgs{}, _ToArgs{})); 404 template <class _FromArgs, class _ToArgs> 405 using __assignable = decltype(__do_test<is_assignable>(_ToArgs{}, _FromArgs{})); 406}; 407 408// __tuple_convertible 409 410template <class _Tp, class _Up, bool = __tuple_like<typename remove_reference<_Tp>::type>::value, 411 bool = __tuple_like<_Up>::value> 412struct __tuple_convertible 413 : public false_type {}; 414 415template <class _Tp, class _Up> 416struct __tuple_convertible<_Tp, _Up, true, true> 417 : public __tuple_sfinae_base::__convertible< 418 typename __make_tuple_types<_Tp>::type 419 , typename __make_tuple_types<_Up>::type 420 > 421{}; 422 423// __tuple_constructible 424 425template <class _Tp, class _Up, bool = __tuple_like<typename remove_reference<_Tp>::type>::value, 426 bool = __tuple_like<_Up>::value> 427struct __tuple_constructible 428 : public false_type {}; 429 430template <class _Tp, class _Up> 431struct __tuple_constructible<_Tp, _Up, true, true> 432 : public __tuple_sfinae_base::__constructible< 433 typename __make_tuple_types<_Tp>::type 434 , typename __make_tuple_types<_Up>::type 435 > 436{}; 437 438// __tuple_assignable 439 440template <class _Tp, class _Up, bool = __tuple_like<typename remove_reference<_Tp>::type>::value, 441 bool = __tuple_like<_Up>::value> 442struct __tuple_assignable 443 : public false_type {}; 444 445template <class _Tp, class _Up> 446struct __tuple_assignable<_Tp, _Up, true, true> 447 : public __tuple_sfinae_base::__assignable< 448 typename __make_tuple_types<_Tp>::type 449 , typename __make_tuple_types<_Up&>::type 450 > 451{}; 452 453 454template <size_t _Ip, class ..._Tp> 455class _LIBCPP_TYPE_VIS_ONLY tuple_element<_Ip, tuple<_Tp...> > 456{ 457public: 458 typedef typename tuple_element<_Ip, __tuple_types<_Tp...> >::type type; 459}; 460 461#if _LIBCPP_STD_VER > 11 462template <size_t _Ip, class ..._Tp> 463using tuple_element_t = typename tuple_element <_Ip, _Tp...>::type; 464#endif 465 466#endif // _LIBCPP_HAS_NO_VARIADICS 467 468#ifndef _LIBCPP_CXX03_LANG 469template <bool _IsTuple, class _SizeTrait, size_t _Expected> 470struct __tuple_like_with_size_imp : false_type {}; 471 472template <class _SizeTrait, size_t _Expected> 473struct __tuple_like_with_size_imp<true, _SizeTrait, _Expected> 474 : integral_constant<bool, _SizeTrait::value == _Expected> {}; 475 476template <class _Tuple, size_t _ExpectedSize, 477 class _RawTuple = typename __uncvref<_Tuple>::type> 478using __tuple_like_with_size = __tuple_like_with_size_imp< 479 __tuple_like<_RawTuple>::value, 480 tuple_size<_RawTuple>, _ExpectedSize 481 >; 482 483struct _LIBCPP_TYPE_VIS __check_tuple_constructor_fail { 484 template <class ...> 485 static constexpr bool __enable_default() { return false; } 486 template <class ...> 487 static constexpr bool __enable_explicit() { return false; } 488 template <class ...> 489 static constexpr bool __enable_implicit() { return false; } 490 template <class ...> 491 static constexpr bool __enable_assign() { return false; } 492}; 493#endif 494 495#if _LIBCPP_STD_VER > 14 496 497template <bool _CanCopy, bool _CanMove> 498struct __sfinae_ctor_base {}; 499template <> 500struct __sfinae_ctor_base<false, false> { 501 __sfinae_ctor_base() = default; 502 __sfinae_ctor_base(__sfinae_ctor_base const&) = delete; 503 __sfinae_ctor_base(__sfinae_ctor_base &&) = delete; 504 __sfinae_ctor_base& operator=(__sfinae_ctor_base const&) = default; 505 __sfinae_ctor_base& operator=(__sfinae_ctor_base&&) = default; 506}; 507template <> 508struct __sfinae_ctor_base<true, false> { 509 __sfinae_ctor_base() = default; 510 __sfinae_ctor_base(__sfinae_ctor_base const&) = default; 511 __sfinae_ctor_base(__sfinae_ctor_base &&) = delete; 512 __sfinae_ctor_base& operator=(__sfinae_ctor_base const&) = default; 513 __sfinae_ctor_base& operator=(__sfinae_ctor_base&&) = default; 514}; 515template <> 516struct __sfinae_ctor_base<false, true> { 517 __sfinae_ctor_base() = default; 518 __sfinae_ctor_base(__sfinae_ctor_base const&) = delete; 519 __sfinae_ctor_base(__sfinae_ctor_base &&) = default; 520 __sfinae_ctor_base& operator=(__sfinae_ctor_base const&) = default; 521 __sfinae_ctor_base& operator=(__sfinae_ctor_base&&) = default; 522}; 523 524template <bool _CanCopy, bool _CanMove> 525struct __sfinae_assign_base {}; 526template <> 527struct __sfinae_assign_base<false, false> { 528 __sfinae_assign_base() = default; 529 __sfinae_assign_base(__sfinae_assign_base const&) = default; 530 __sfinae_assign_base(__sfinae_assign_base &&) = default; 531 __sfinae_assign_base& operator=(__sfinae_assign_base const&) = delete; 532 __sfinae_assign_base& operator=(__sfinae_assign_base&&) = delete; 533}; 534template <> 535struct __sfinae_assign_base<true, false> { 536 __sfinae_assign_base() = default; 537 __sfinae_assign_base(__sfinae_assign_base const&) = default; 538 __sfinae_assign_base(__sfinae_assign_base &&) = default; 539 __sfinae_assign_base& operator=(__sfinae_assign_base const&) = default; 540 __sfinae_assign_base& operator=(__sfinae_assign_base&&) = delete; 541}; 542template <> 543struct __sfinae_assign_base<false, true> { 544 __sfinae_assign_base() = default; 545 __sfinae_assign_base(__sfinae_assign_base const&) = default; 546 __sfinae_assign_base(__sfinae_assign_base &&) = default; 547 __sfinae_assign_base& operator=(__sfinae_assign_base const&) = delete; 548 __sfinae_assign_base& operator=(__sfinae_assign_base&&) = default; 549}; 550#endif // _LIBCPP_STD_VER > 14 551 552_LIBCPP_END_NAMESPACE_STD 553 554#endif // _LIBCPP___TUPLE 555