#include <iostream>
#include <memory>

#include <grpc++/grpc++.h>

#include "google/pubsub/v1/pubsub.grpc.pb.h"

auto main() -> int {
    using grpc::ClientContext;
    using google::pubsub::v1::Subscriber;
    using google::pubsub::v1::PullRequest;
    using google::pubsub::v1::PullResponse;

    auto creds = grpc::GoogleDefaultCredentials();
    auto stub = std::make_unique<Subscriber::Stub>(grpc::CreateChannel("pubsub.googleapis.com", creds));

    PullRequest request;
    auto const subscription_string = "projects/pubsub-cpp-api-1504713535863/subscriptions/testing";
    request.set_subscription(subscription_string);
    request.set_max_messages(50);
    request.set_return_immediately(false);

    PullResponse response;
    ClientContext ctx;

    auto status = stub->Pull(&ctx, request, &response);
    if (!status.ok()) {
        // ...
    }

    // Do something with "response".
}