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 #include "src/__support/macros/config.h" 13 14 namespace LIBC_NAMESPACE_DECL { 15 namespace cpp { 16 17 // integer_sequence 18 template <typename T, T... Ints> struct integer_sequence { 19 static_assert(cpp::is_integral_v<T>); 20 template <T Next> using append = integer_sequence<T, Ints..., Next>; 21 }; 22 23 namespace detail { 24 template <typename T, int N> struct make_integer_sequence { 25 using type = 26 typename make_integer_sequence<T, N - 1>::type::template append<N>; 27 }; 28 template <typename T> struct make_integer_sequence<T, -1> { 29 using type = integer_sequence<T>; 30 }; 31 } // namespace detail 32 33 template <typename T, int N> 34 using make_integer_sequence = 35 typename detail::make_integer_sequence<T, N - 1>::type; 36 37 } // namespace cpp 38 } // namespace LIBC_NAMESPACE_DECL 39 40 #endif // LLVM_LIBC_SRC___SUPPORT_CPP_UTILITY_INTEGER_SEQUENCE_H 41