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