chromium/third_party/grpc/src/src/core/lib/promise/race.h

// Copyright 2021 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 GRPC_SRC_CORE_LIB_PROMISE_RACE_H
#define GRPC_SRC_CORE_LIB_PROMISE_RACE_H

#include <grpc/support/port_platform.h>

#include <type_traits>
#include <utility>

namespace grpc_core {

namespace promise_detail {

// Implementation type for Race combinator.
template <typename... Promises>
class Race;

Race<Promise, Promises...>;

Race<Promise>;

}  // namespace promise_detail

/// Run all the promises, return the first result that's available.
/// If two results are simultaneously available, bias towards the first result
/// listed.
template <typename... Promises>
promise_detail::Race<Promises...> Race(Promises... promises) { … }

}  // namespace grpc_core

#endif  // GRPC_SRC_CORE_LIB_PROMISE_RACE_H