1fe6060f1SDimitry Andric //===----------------------------------------------------------------------===// 2fe6060f1SDimitry Andric // 3fe6060f1SDimitry Andric // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 4fe6060f1SDimitry Andric // See https://llvm.org/LICENSE.txt for license information. 5fe6060f1SDimitry Andric // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 6fe6060f1SDimitry Andric // 7fe6060f1SDimitry Andric //===----------------------------------------------------------------------===// 8fe6060f1SDimitry Andric 9fe6060f1SDimitry Andric #ifndef _LIBCPP___UTILITY_INTEGER_SEQUENCE_H 10fe6060f1SDimitry Andric #define _LIBCPP___UTILITY_INTEGER_SEQUENCE_H 11fe6060f1SDimitry Andric 12fe6060f1SDimitry Andric #include <__config> 13bdd1243dSDimitry Andric #include <__type_traits/is_integral.h> 14bdd1243dSDimitry Andric #include <cstddef> 15fe6060f1SDimitry Andric 16fe6060f1SDimitry Andric #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER) 17fe6060f1SDimitry Andric # pragma GCC system_header 18fe6060f1SDimitry Andric #endif 19fe6060f1SDimitry Andric 20fe6060f1SDimitry Andric _LIBCPP_BEGIN_NAMESPACE_STD 21fe6060f1SDimitry Andric 22cb14a3feSDimitry Andric template <size_t...> 23cb14a3feSDimitry Andric struct __tuple_indices; 24bdd1243dSDimitry Andric 25bdd1243dSDimitry Andric template <class _IdxType, _IdxType... _Values> 26bdd1243dSDimitry Andric struct __integer_sequence { 27bdd1243dSDimitry Andric template <template <class _OIdxType, _OIdxType...> class _ToIndexSeq, class _ToIndexType> 28bdd1243dSDimitry Andric using __convert = _ToIndexSeq<_ToIndexType, _Values...>; 29bdd1243dSDimitry Andric 30bdd1243dSDimitry Andric template <size_t _Sp> 31bdd1243dSDimitry Andric using __to_tuple_indices = __tuple_indices<(_Values + _Sp)...>; 32bdd1243dSDimitry Andric }; 33bdd1243dSDimitry Andric 34bdd1243dSDimitry Andric #if __has_builtin(__make_integer_seq) 35bdd1243dSDimitry Andric template <size_t _Ep, size_t _Sp> 36bdd1243dSDimitry Andric using __make_indices_imp = 37cb14a3feSDimitry Andric typename __make_integer_seq<__integer_sequence, size_t, _Ep - _Sp>::template __to_tuple_indices<_Sp>; 38*0fca6ea1SDimitry Andric #elif __has_builtin(__integer_pack) 39bdd1243dSDimitry Andric template <size_t _Ep, size_t _Sp> 40*0fca6ea1SDimitry Andric using __make_indices_imp = 41*0fca6ea1SDimitry Andric typename __integer_sequence<size_t, __integer_pack(_Ep - _Sp)...>::template __to_tuple_indices<_Sp>; 42*0fca6ea1SDimitry Andric #else 43*0fca6ea1SDimitry Andric # error "No known way to get an integer pack from the compiler" 44bdd1243dSDimitry Andric #endif 45bdd1243dSDimitry Andric 4606c3fb27SDimitry Andric #if _LIBCPP_STD_VER >= 14 47fe6060f1SDimitry Andric 48fe6060f1SDimitry Andric template <class _Tp, _Tp... _Ip> 49cb14a3feSDimitry Andric struct _LIBCPP_TEMPLATE_VIS integer_sequence { 50fe6060f1SDimitry Andric typedef _Tp value_type; 51cb14a3feSDimitry Andric static_assert(is_integral<_Tp>::value, "std::integer_sequence can only be instantiated with an integral type"); 52cb14a3feSDimitry Andric static _LIBCPP_HIDE_FROM_ABI constexpr size_t size() noexcept { return sizeof...(_Ip); } 53fe6060f1SDimitry Andric }; 54fe6060f1SDimitry Andric 55fe6060f1SDimitry Andric template <size_t... _Ip> 56fe6060f1SDimitry Andric using index_sequence = integer_sequence<size_t, _Ip...>; 57fe6060f1SDimitry Andric 58*0fca6ea1SDimitry Andric # if __has_builtin(__make_integer_seq) 59fe6060f1SDimitry Andric 60fe6060f1SDimitry Andric template <class _Tp, _Tp _Ep> 61*0fca6ea1SDimitry Andric using make_integer_sequence _LIBCPP_NODEBUG = __make_integer_seq<integer_sequence, _Tp, _Ep>; 62*0fca6ea1SDimitry Andric 63*0fca6ea1SDimitry Andric # elif __has_builtin(__integer_pack) 64*0fca6ea1SDimitry Andric 65*0fca6ea1SDimitry Andric template <class _Tp, _Tp _SequenceSize> 66*0fca6ea1SDimitry Andric using make_integer_sequence _LIBCPP_NODEBUG = integer_sequence<_Tp, __integer_pack(_SequenceSize)...>; 67fe6060f1SDimitry Andric 68fe6060f1SDimitry Andric # else 69*0fca6ea1SDimitry Andric # error "No known way to get an integer pack from the compiler" 70fe6060f1SDimitry Andric # endif 71fe6060f1SDimitry Andric 72fe6060f1SDimitry Andric template <size_t _Np> 73fe6060f1SDimitry Andric using make_index_sequence = make_integer_sequence<size_t, _Np>; 74fe6060f1SDimitry Andric 75fe6060f1SDimitry Andric template <class... _Tp> 76fe6060f1SDimitry Andric using index_sequence_for = make_index_sequence<sizeof...(_Tp)>; 77fe6060f1SDimitry Andric 7806c3fb27SDimitry Andric # if _LIBCPP_STD_VER >= 20 79bdd1243dSDimitry Andric // Executes __func for every element in an index_sequence. 80bdd1243dSDimitry Andric template <size_t... _Index, class _Function> 81bdd1243dSDimitry Andric _LIBCPP_HIDE_FROM_ABI constexpr void __for_each_index_sequence(index_sequence<_Index...>, _Function __func) { 82bdd1243dSDimitry Andric (__func.template operator()<_Index>(), ...); 83bdd1243dSDimitry Andric } 8406c3fb27SDimitry Andric # endif // _LIBCPP_STD_VER >= 20 85bdd1243dSDimitry Andric 8606c3fb27SDimitry Andric #endif // _LIBCPP_STD_VER >= 14 87fe6060f1SDimitry Andric 88fe6060f1SDimitry Andric _LIBCPP_END_NAMESPACE_STD 89fe6060f1SDimitry Andric 90fe6060f1SDimitry Andric #endif // _LIBCPP___UTILITY_INTEGER_SEQUENCE_H 91