Cloud Document AI API C++ Client Library

#include "google/cloud/documentai/v1/document_processor_client.h"
#include "google/cloud/location.h"
#include <fstream>
#include <iostream>
#include <string>
int main(int argc, char* argv[]) try {
 if (argc != 5) {
 std::cerr << "Usage: " << argv[0]
 << " project-id location-id processor-id filename (PDF only)\n";
 return 1;
 }
 std::string const location_id = argv[2];
 if (location_id != "us" && location_id != "eu") {
 std::cerr << "location-id must be either 'us' or 'eu'\n";
 return 1;
 }
 auto const location = google::cloud::Location(argv[1], location_id);
 namespace documentai = ::google::cloud::documentai_v1;
 auto client = documentai::DocumentProcessorServiceClient(
 documentai::MakeDocumentProcessorServiceConnection(
 location.location_id()));
 google::cloud::documentai::v1::ProcessRequest req;
 req.set_name(location.FullName() + "/processors/" + argv[3]);
 req.set_skip_human_review(true);
 auto& doc = *req.mutable_raw_document();
 doc.set_mime_type("application/pdf");
 std::ifstream is(argv[4]);
 doc.set_content(std::string{std::istreambuf_iterator<char>(is), {}});
 auto resp = client.ProcessDocument(std::move(req));
 if (!resp) throw std::move(resp).status();
 std::cout << resp->document().text() << "\n";
 return 0;
} catch (google::cloud::Status const& status) {
 std::cerr << "google::cloud::Status thrown: " << status << "\n";
 return 1;
}