| // Protocol Buffers - Google's data interchange format |
| // Copyright 2024 Google LLC. All rights reserved. |
| // |
| // Use of this source code is governed by a BSD-style |
| // license that can be found in the LICENSE file or at |
| // https://developers.google.com/open-source/licenses/bsd |
| |
| #ifndef PROTOBUF_HPB_REQUIRES_H_ |
| #define PROTOBUF_HPB_REQUIRES_H_ |
| |
| #include <type_traits> |
| namespace hpb::internal { |
| // Ports C++20 `requires` to C++17. |
| // C++20 ideal: |
| // if constexpr (requires { t.foo(); }) { ... } |
| // Our C++17 stopgap solution: |
| // if constexpr (Requires<T>([](auto x) -> decltype(x.foo()) {})) { ... } |
| template <typename... T, typename F> |
| constexpr bool Requires(F) { |
| return std::is_invocable_v<F, T...>; |
| } |
| } // namespace hpb::internal |
| |
| #endif // PROTOBUF_HPB_REQUIRES_H_ |
