1 | //===-- integer_sequence utility --------------------------------*- C++ -*-===// |
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 | #ifndef LLVM_LIBC_SRC___SUPPORT_CPP_UTILITY_INTEGER_SEQUENCE_H |
9 | #define LLVM_LIBC_SRC___SUPPORT_CPP_UTILITY_INTEGER_SEQUENCE_H |
10 | |
11 | #include "src/__support/CPP/type_traits/is_integral.h" |
12 | |
13 | namespace LIBC_NAMESPACE::cpp { |
14 | |
15 | // integer_sequence |
16 | template <typename T, T... Ints> struct integer_sequence { |
17 | static_assert(cpp::is_integral_v<T>); |
18 | template <T Next> using append = integer_sequence<T, Ints..., Next>; |
19 | }; |
20 | |
21 | namespace detail { |
22 | template <typename T, int N> struct make_integer_sequence { |
23 | using type = |
24 | typename make_integer_sequence<T, N - 1>::type::template append<N>; |
25 | }; |
26 | template <typename T> struct make_integer_sequence<T, -1> { |
27 | using type = integer_sequence<T>; |
28 | }; |
29 | } // namespace detail |
30 | |
31 | template <typename T, int N> |
32 | using make_integer_sequence = |
33 | typename detail::make_integer_sequence<T, N - 1>::type; |
34 | |
35 | } // namespace LIBC_NAMESPACE::cpp |
36 | |
37 | #endif // LLVM_LIBC_SRC___SUPPORT_CPP_UTILITY_INTEGER_SEQUENCE_H |
38 | |