| //===----------------------------------------------------------------------===// |
| // |
| // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. |
| // See https://llvm.org/LICENSE.txt for license information. |
| // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception |
| // |
| //===----------------------------------------------------------------------===// |
| |
| #ifndef _LIBCPP___UTILITY_INTEGER_SEQUENCE_H |
| #define _LIBCPP___UTILITY_INTEGER_SEQUENCE_H |
| |
| #include <__config> |
| #include <type_traits> |
| |
| #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER) |
| #pragma GCC system_header |
| #endif |
| |
| _LIBCPP_BEGIN_NAMESPACE_STD |
| |
| #if _LIBCPP_STD_VER > 11 |
| |
| template<class _Tp, _Tp... _Ip> |
| struct _LIBCPP_TEMPLATE_VIS integer_sequence |
| { |
| typedef _Tp value_type; |
| static_assert( is_integral<_Tp>::value, |
| "std::integer_sequence can only be instantiated with an integral type" ); |
| static |
| _LIBCPP_INLINE_VISIBILITY |
| constexpr |
| size_t |
| size() noexcept { return sizeof...(_Ip); } |
| }; |
| |
| template<size_t... _Ip> |
| using index_sequence = integer_sequence<size_t, _Ip...>; |
| |
| #if __has_builtin(__make_integer_seq) && !defined(_LIBCPP_TESTING_FALLBACK_MAKE_INTEGER_SEQUENCE) |
| |
| template <class _Tp, _Tp _Ep> |
| using __make_integer_sequence _LIBCPP_NODEBUG = __make_integer_seq<integer_sequence, _Tp, _Ep>; |
| |
| #else |
| |
| template<typename _Tp, _Tp _Np> using __make_integer_sequence_unchecked _LIBCPP_NODEBUG = |
| typename __detail::__make<_Np>::type::template __convert<integer_sequence, _Tp>; |
| |
| template <class _Tp, _Tp _Ep> |
| struct __make_integer_sequence_checked |
| { |
| static_assert(is_integral<_Tp>::value, |
| "std::make_integer_sequence can only be instantiated with an integral type" ); |
| static_assert(0 <= _Ep, "std::make_integer_sequence must have a non-negative sequence length"); |
| // Workaround GCC bug by preventing bad installations when 0 <= _Ep |
| // https://gcc.gnu.org/bugzilla/show_bug.cgi?id=68929 |
| typedef _LIBCPP_NODEBUG __make_integer_sequence_unchecked<_Tp, 0 <= _Ep ? _Ep : 0> type; |
| }; |
| |
| template <class _Tp, _Tp _Ep> |
| using __make_integer_sequence _LIBCPP_NODEBUG = typename __make_integer_sequence_checked<_Tp, _Ep>::type; |
| |
| #endif |
| |
| template<class _Tp, _Tp _Np> |
| using make_integer_sequence = __make_integer_sequence<_Tp, _Np>; |
| |
| template<size_t _Np> |
| using make_index_sequence = make_integer_sequence<size_t, _Np>; |
| |
| template<class... _Tp> |
| using index_sequence_for = make_index_sequence<sizeof...(_Tp)>; |
| |
| #endif // _LIBCPP_STD_VER > 11 |
| |
| _LIBCPP_END_NAMESPACE_STD |
| |
| #endif // _LIBCPP___UTILITY_INTEGER_SEQUENCE_H |