chromium/third_party/grpc/src/include/grpcpp/support/callback_common.h

//
//
// Copyright 2018 gRPC 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 GRPCPP_SUPPORT_CALLBACK_COMMON_H
#define GRPCPP_SUPPORT_CALLBACK_COMMON_H

#include <functional>

#include <grpc/grpc.h>
#include <grpc/impl/grpc_types.h>
#include <grpc/support/log.h>
#include <grpcpp/impl/call.h>
#include <grpcpp/impl/codegen/channel_interface.h>
#include <grpcpp/impl/completion_queue_tag.h>
#include <grpcpp/support/config.h>
#include <grpcpp/support/status.h>

namespace grpc {
namespace internal {

/// An exception-safe way of invoking a user-specified callback function
// TODO(vjpai): decide whether it is better for this to take a const lvalue
//              parameter or an rvalue parameter, or if it even matters
template <class Func, class... Args>
void CatchingCallback(Func&& func, Args&&... args) { … }

template <class Reactor, class Func, class... Args>
Reactor* CatchingReactorGetter(Func&& func, Args&&... args) { … }

// The contract on these tags is that they are single-shot. They must be
// constructed and then fired at exactly one point. There is no expectation
// that they can be reused without reconstruction.

class CallbackWithStatusTag : public grpc_completion_queue_functor { … };

/// CallbackWithSuccessTag can be reused multiple times, and will be used in
/// this fashion for streaming operations. As a result, it shouldn't clear
/// anything up until its destructor
class CallbackWithSuccessTag : public grpc_completion_queue_functor { … };

}  // namespace internal
}  // namespace grpc

#endif  // GRPCPP_SUPPORT_CALLBACK_COMMON_H