| // Copyright 2020 The Dawn Authors |
| // |
| // Licensed under the Apache License, Version 2.0 (the "License"); |
| // you may not use this file except in compliance with the License. |
| // You may obtain a copy of the License at |
| // |
| // http://www.apache.org/licenses/LICENSE-2.0 |
| // |
| // Unless required by applicable law or agreed to in writing, software |
| // distributed under the License is distributed on an "AS IS" BASIS, |
| // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| // See the License for the specific language governing permissions and |
| // limitations under the License. |
| |
| #ifndef SRC_DAWN_COMMON_UNDERLYINGTYPE_H_ |
| #define SRC_DAWN_COMMON_UNDERLYINGTYPE_H_ |
| |
| #include <type_traits> |
| |
| namespace dawn { |
| |
| // UnderlyingType is similar to std::underlying_type_t. It is a passthrough for already |
| // integer types which simplifies getting the underlying primitive type for an arbitrary |
| // template parameter. It includes a specialization for detail::TypedIntegerImpl which yields |
| // the wrapped integer type. |
| namespace detail { |
| template <typename T, typename Enable = void> |
| struct UnderlyingTypeImpl; |
| |
| template <typename I> |
| struct UnderlyingTypeImpl<I, typename std::enable_if_t<std::is_integral<I>::value>> { |
| using type = I; |
| }; |
| |
| template <typename E> |
| struct UnderlyingTypeImpl<E, typename std::enable_if_t<std::is_enum<E>::value>> { |
| using type = std::underlying_type_t<E>; |
| }; |
| |
| // Forward declare the TypedInteger impl. |
| template <typename Tag, typename T> |
| class TypedIntegerImpl; |
| |
| template <typename Tag, typename I> |
| struct UnderlyingTypeImpl<TypedIntegerImpl<Tag, I>> { |
| using type = typename UnderlyingTypeImpl<I>::type; |
| }; |
| } // namespace detail |
| |
| template <typename T> |
| using UnderlyingType = typename detail::UnderlyingTypeImpl<T>::type; |
| |
| } // namespace dawn |
| |
| #endif // SRC_DAWN_COMMON_UNDERLYINGTYPE_H_ |