dom/canvas/IsEnumCase.h

   1 /* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
   2 /* This Source Code Form is subject to the terms of the Mozilla Public
   3  * License, v. 2.0. If a copy of the MPL was not distributed with this
   4  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   5
   6 #ifndef MOZILLA_DOM_ISENUMCASE_H
   7 #define MOZILLA_DOM_ISENUMCASE_H
   8
   9 #include <optional>
  10 #include <type_traits>
  11
  12 namespace mozilla {
  13
  14 template <class T>
  15 bool IsEnumCase(T);
  16
  17 template <class E>
  18 inline constexpr std::optional<E> AsEnumCase(
  19     const std::underlying_type_t<E> raw) {
  20   const auto ret = static_cast<E>(raw);
  21   if (!IsEnumCase(ret)) return {};
  22   return ret;
  23 }
  24
  25 }  // namespace mozilla
  26
  27 #endif