/* * Copyright (C) 2021 The Android Open Source Project * * 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 INCLUDE_PERFETTO_BASE_TEMPLATE_UTIL_H_ #define INCLUDE_PERFETTO_BASE_TEMPLATE_UTIL_H_ #include <cstddef> #include <type_traits> namespace perfetto { namespace base { // Helper to express preferences in an overload set. If more than one overload // is available for a given set of parameters the overload with the higher // priority will be chosen. template <size_t I> struct priority_tag : priority_tag<I - 1> { … }; template <> struct priority_tag<0> { … }; // enable_if_t is an implementation of std::enable_if_t from C++14. // // Specification: // https://en.cppreference.com/w/cpp/types/enable_if enable_if_t; // decay_t is an implementation of std::decay_t from C++14. // // Specification: // https://en.cppreference.com/w/cpp/types/decay decay_t; // remove_cvref is an implementation of std::remove_cvref from // C++20. // // Specification: // https://en.cppreference.com/w/cpp/types/remove_cvref template <class T> struct remove_cvref { … }; remove_cvref_t; // Check if a given type is a specialization of a given template: // is_specialization<T, std::vector>::value. template <typename Type, template <typename...> class Template> struct is_specialization : std::false_type { … }; is_specialization<Ref<Args...>, Ref>; } // namespace base } // namespace perfetto #endif // INCLUDE_PERFETTO_BASE_TEMPLATE_UTIL_H_