libc/src/__support/CPP/utility.h

   1 //===-- Analogous to <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
   9 #ifndef LLVM_LIBC_SRC_SUPPORT_CPP_UTILITY_H
  10 #define LLVM_LIBC_SRC_SUPPORT_CPP_UTILITY_H
  11
  12 #include "src/__support/CPP/type_traits.h"
  13 #include "src/__support/macros/attributes.h"
  14
  15 namespace __llvm_libc::cpp {
  16
  17 template <typename T, T... Ints> struct integer_sequence {
  18   static_assert(is_integral_v<T>);
  19   template <T Next> using append = integer_sequence<T, Ints..., Next>;
  20 };
  21
  22 namespace internal {
  23
  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
  29 template <typename T> struct make_integer_sequence<T, -1> {
  30   using type = integer_sequence<T>;
  31 };
  32
  33 } // namespace internal
  34
  35 template <typename T, int N>
  36 using make_integer_sequence =
  37     typename internal::make_integer_sequence<T, N - 1>::type;
  38
  39 template <typename T>
  40 LIBC_INLINE constexpr T &&forward(typename remove_reference<T>::type &value) {
  41   return static_cast<T &&>(value);
  42 }
  43
  44 template <typename T>
  45 LIBC_INLINE constexpr T &&forward(typename remove_reference<T>::type &&value) {
  46   return static_cast<T &&>(value);
  47 }
  48
  49 template <typename T>
  50 LIBC_INLINE constexpr typename remove_reference<T>::type &&move(T &&value) {
  51   return static_cast<typename remove_reference<T>::type &&>(value);
  52 }
  53
  54 } // namespace __llvm_libc::cpp
  55
  56 #endif // LLVM_LIBC_SRC_SUPPORT_CPP_UTILITY_H