1 //===----------------------------------------------------------------------===// 2 // 3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 4 // See https://llvm.org/LICENSE.txt for license information. 5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 6 // 7 //===----------------------------------------------------------------------===// 8 9 #ifndef _LIBCPP___CXX03___UTILITY_INTEGER_SEQUENCE_H 10 #define _LIBCPP___CXX03___UTILITY_INTEGER_SEQUENCE_H 11 12 #include <__cxx03/__config> 13 #include <__cxx03/__type_traits/is_integral.h> 14 #include <__cxx03/cstddef> 15 16 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER) 17 # pragma GCC system_header 18 #endif 19 20 _LIBCPP_BEGIN_NAMESPACE_STD 21 22 template <size_t...> 23 struct __tuple_indices; 24 25 template <class _IdxType, _IdxType... _Values> 26 struct __integer_sequence { 27 template <template <class _OIdxType, _OIdxType...> class _ToIndexSeq, class _ToIndexType> 28 using __convert = _ToIndexSeq<_ToIndexType, _Values...>; 29 30 template <size_t _Sp> 31 using __to_tuple_indices = __tuple_indices<(_Values + _Sp)...>; 32 }; 33 34 #if __has_builtin(__make_integer_seq) 35 template <size_t _Ep, size_t _Sp> 36 using __make_indices_imp = 37 typename __make_integer_seq<__integer_sequence, size_t, _Ep - _Sp>::template __to_tuple_indices<_Sp>; 38 #elif __has_builtin(__integer_pack) 39 template <size_t _Ep, size_t _Sp> 40 using __make_indices_imp = 41 typename __integer_sequence<size_t, __integer_pack(_Ep - _Sp)...>::template __to_tuple_indices<_Sp>; 42 #else 43 # error "No known way to get an integer pack from the compiler" 44 #endif 45 46 _LIBCPP_END_NAMESPACE_STD 47 48 #endif // _LIBCPP___CXX03___UTILITY_INTEGER_SEQUENCE_H 49