xref: /aosp_15_r20/external/grpc-grpc/src/core/lib/gprpp/down_cast.h (revision cc02d7e222339f7a4f6ba5f422e6413f4bd931f2)
1 // Copyright 2024 gRPC authors.
2 //
3 // Licensed under the Apache License, Version 2.0 (the "License");
4 // you may not use this file except in compliance with the License.
5 // You may obtain a copy of the License at
6 //
7 //     http://www.apache.org/licenses/LICENSE-2.0
8 //
9 // Unless required by applicable law or agreed to in writing, software
10 // distributed under the License is distributed on an "AS IS" BASIS,
11 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12 // See the License for the specific language governing permissions and
13 // limitations under the License.
14 
15 #ifndef GRPC_SRC_CORE_LIB_GPRPP_DOWN_CAST_H
16 #define GRPC_SRC_CORE_LIB_GPRPP_DOWN_CAST_H
17 
18 #include <grpc/support/port_platform.h>
19 
20 #include <type_traits>
21 
22 #include "absl/base/config.h"
23 
24 #include <grpc/support/log.h>
25 
26 namespace grpc_core {
27 
28 template <typename To, typename From>
DownCast(From * f)29 inline To DownCast(From* f) {
30   static_assert(
31       std::is_base_of<From, typename std::remove_pointer<To>::type>::value,
32       "DownCast requires a base-to-derived relationship");
33 // If we have RTTI & we're in debug, assert that the cast is legal.
34 #if ABSL_INTERNAL_HAS_RTTI
35 #ifndef NDEBUG
36   if (f != nullptr) GPR_ASSERT(dynamic_cast<To>(f) != nullptr);
37 #endif
38 #endif
39   return static_cast<To>(f);
40 }
41 
42 template <typename To, typename From>
DownCast(From & f)43 inline To DownCast(From& f) {
44   return *DownCast<typename std::remove_reference<To>::type*>(&f);
45 }
46 
47 }  // namespace grpc_core
48 
49 #endif  // GRPC_SRC_CORE_LIB_GPRPP_DOWN_CAST_H
50