recom_examples.patch

diff --git a/tensorflow/recom/BUILD b/tensorflow/recom/BUILD
new file mode 100644
index 00000000000..a6ab99eb524
--- /dev/null
+++ b/tensorflow/recom/BUILD
@@ -0,0 +1,54 @@
+licenses(["notice"])  # Apache 2.0
+
+package(default_visibility = ["//visibility:public"])
+
+load("//tensorflow:tensorflow.bzl", "tf_cc_binary")
+
+tf_cc_binary(
+    name = "benchmark_multi_thread",
+    srcs = ["benchmark_multi_thread.cu.cc", "cxxopts.hpp"],
+    copts = [
+        "-fexceptions"
+    ],
+    linkopts = [
+        "-rdynamic",
+        "-lpthread",
+        "-lcudart",
+        "-L/usr/local/cuda/lib64" # Replace it if different on your system
+    ],
+    deps = [
+        ":utils",
+        "//tensorflow/cc:client_session",
+        "//tensorflow/core:tensorflow",
+    ]
+)
+
+tf_cc_binary(
+    name = "benchmark_throughput",
+    srcs = ["benchmark_throughput.cc", "cxxopts.hpp"],
+    copts = [
+        "-fexceptions"
+    ],
+    linkopts = [
+        "-rdynamic",
+        "-lpthread",
+    ],
+    deps = [
+        ":utils",
+        "//tensorflow/cc:client_session",
+        "//tensorflow/core:tensorflow",
+    ]
+)
+
+cc_library(
+    name = "utils",
+    srcs = ["utils.cc"],
+    hdrs = ["utils.h"],
+    deps = [
+        "//tensorflow/c:c_api",
+        "//tensorflow/cc:cc_ops",
+        "//tensorflow/core:tensorflow",
+        "//tensorflow/cc/saved_model:signature_constants",
+        "//tensorflow/cc/saved_model:loader"
+    ]
+)
diff --git a/tensorflow/recom/benchmark_multi_thread.cu.cc b/tensorflow/recom/benchmark_multi_thread.cu.cc
new file mode 100644
index 00000000000..4ff79f8467b
--- /dev/null
+++ b/tensorflow/recom/benchmark_multi_thread.cu.cc
@@ -0,0 +1,197 @@
+// Copyright 2023 The RECom Authors. All rights reserved.
+// 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.
+
+#include <cuda_profiler_api.h>
+#include <unistd.h>
+
+#include <chrono>
+#include <cstdlib>
+#include <fstream>
+#include <iostream>
+#include <string>
+#include <thread>
+#include <unordered_map>
+#include <vector>
+
+#include "absl/strings/str_replace.h"
+#include "cxxopts.hpp"
+#include "tensorflow/core/public/session.h"
+#include "utils.h"
+
+using namespace ::tensorflow;
+using namespace ::tensorflow::benchmark;
+
+int main(int argc, char **argv) {
+  cxxopts::Options options("benchmark_multi_thread",
+                           "Benchmark the performance of TF recommendation "
+                           "models with mutliple inference threads");
+
+  // clang-format off
+  options.add_options()
+    ("model_path", "Path of the TF saved model (mandatory)", cxxopts::value<std::string>())
+    ("batch_size", "Inference batch size", cxxopts::value<int>()->default_value("256"))
+    ("serve_workers", "Number of workers serving the requests concurrently", cxxopts::value<int>()->default_value("1"))
+    ("intra_threads", "TF intra_threads_parallelism (CPU)", cxxopts::value<int>()->default_value("0"))
+    ("inter_threads", "TF inter_threads_parallelism (CPU)", cxxopts::value<int>()->default_value("0"))
+    ("num_iterations", "Number of running iteration", cxxopts::value<int>()->default_value("100"))
+    ("lib_path", "Link a TF addon library", cxxopts::value<std::string>())
+    ("disable_gpu", "Disable the Usage of GPU", cxxopts::value<bool>()->default_value("false"))
+    ("embedding_only", "Only process the embedding parts", cxxopts::value<bool>()->default_value("false"))
+    ("cuda_profile", "Profiling the kernels (single thread). Only works when GPU is used", cxxopts::value<bool>()->default_value("false"))
+    ("timeline", "Record the TF timeline (single thread) to the specified path", cxxopts::value<std::string>())
+    ("h,help", "Show usage");
+  // clang-format on
+
+  auto args = options.parse(argc, argv);
+  if (args.count("help")) {
+    std::cout << options.help() << std::endl;
+    exit(0);
+  }
+
+  if (!args.count("model_path")) {
+    std::cerr << "ERROR: model_path must be specified!" << std::endl;
+    std::cerr << options.help() << std::endl;
+    exit(-1);
+  }
+
+  const auto &model_path = args["model_path"].as<std::string>();
+  const auto &batch_size = args["batch_size"].as<int>();
+  const auto &serve_workers = args["serve_workers"].as<int>();
+  const auto &intra_threads = args["intra_threads"].as<int>();
+  const auto &inter_threads = args["inter_threads"].as<int>();
+  const auto &num_iterations = args["num_iterations"].as<int>();
+  const bool &use_gpu = !args["disable_gpu"].as<bool>();
+
+  const bool &use_lib = args.count("lib_path");
+  const std::string &lib_path =
+      use_lib ? args["lib_path"].as<std::string>() : "";
+
+  LOG(INFO) << "Testing with model: " << model_path;
+  LOG(INFO) << "Testing with batch_size: " << batch_size;
+  LOG(INFO) << "Testing with serve_workers: " << serve_workers;
+  LOG(INFO) << "Testing with intra_threads: " << intra_threads;
+  LOG(INFO) << "Testing with inter_threads: " << inter_threads;
+  LOG(INFO) << "Testing with num_iterations: " << num_iterations;
+  LOG(INFO) << "GPU is " << (use_gpu ? "" : "NOT ") << "enabled";
+
+  if (use_lib) {
+    LOG(INFO) << "Testing with library: " << lib_path;
+    LoadOpLibrary(lib_path);
+  }
+
+  std::shared_ptr<SavedModelBundle> bundle;
+  LoadSavedModelWrap(model_path, intra_threads, inter_threads, bundle, use_gpu);
+  const auto &gd = bundle->meta_graph_def.graph_def();
+
+  std::vector<std::string> outputs;
+  if (!args["embedding_only"].as<bool>()) {
+    ExtractGraphOutputs(bundle, outputs);
+  } else {
+    ExtractGraphConcats(gd, outputs);
+  }
+
+  auto RunPredict =
+      [&](const std::vector<std::pair<std::string, Tensor>> &inputs,
+          std::vector<Tensor> &results) {
+        Status status = bundle->session->Run(inputs, outputs, {}, &results);
+        if (!status.ok()) {
+          LOG(ERROR) << "Failed to predict! status = " << status.ToString();
+          exit(-1);
+        }
+      };
+
+  auto RunMultiThreads =
+      [&](const std::vector<std::pair<std::string, Tensor>> &inputs,
+          std::vector<Tensor> &results, int batch_size) {
+        // LOG(INFO) << "Fetch nodes: " << absl::StrJoin(outputs, ", ");
+
+        using milli = std::chrono::milliseconds;
+
+        LOG(INFO) << "Start warmup predict";
+
+        auto t1 = std::chrono::high_resolution_clock::now();
+        RunPredict(inputs, results);
+        auto t2 = std::chrono::high_resolution_clock::now();
+
+        int warmup_time = std::chrono::duration_cast<milli>(t2 - t1).count();
+        LOG(INFO) << "Warmup done. Time: " << warmup_time << "ms";
+
+        auto run_thread = [&](int idx, int total) {
+          auto t1 = std::chrono::high_resolution_clock::now();
+          for (int i = 0; i < num_iterations; ++i) {
+            std::vector<Tensor> res;
+            RunPredict(inputs, res);
+          }
+          auto t2 = std::chrono::high_resolution_clock::now();
+
+          LOG(INFO) << "Batch size " << batch_size << ", sess run "
+                    << num_iterations << " times, average latency: "
+                    << static_cast<float>(
+                           std::chrono::duration_cast<milli>(t2 - t1).count()) /
+                           num_iterations
+                    << " ms";
+        };
+
+        auto t3 = std::chrono::high_resolution_clock::now();
+        std::vector<std::thread> threads;
+        for (int i = 0; i < serve_workers; i++) {
+          threads.push_back(std::thread(run_thread, i, serve_workers));
+        }
+        for (auto &thread : threads) {
+          thread.join();
+        }
+        auto t4 = std::chrono::high_resolution_clock::now();
+
+        int total_latency = std::chrono::duration_cast<milli>(t4 - t3).count();
+        LOG(INFO) << "Total latency: " << total_latency << "ms";
+
+        int throughput = serve_workers * num_iterations * batch_size /
+                         static_cast<float>(total_latency) * 1000;
+        LOG(INFO) << "Batch size: " << batch_size
+                  << ", Throughput: " << throughput << " inference/s";
+      };
+
+  std::vector<std::pair<std::string, Tensor>> inputs;
+  ConstructGraphInputs(gd, batch_size, inputs);
+
+  std::vector<Tensor> results;
+  RunMultiThreads(inputs, results, batch_size);
+
+  if (args.count("cuda_profile")) {
+    for (int i = 0; i < 10; ++i)
+      RunPredict(inputs, results);
+
+    cudaProfilerStart();
+    RunPredict(inputs, results);
+    cudaProfilerStop();
+  }
+
+  if (args.count("timeline")) {
+    for (int i = 0; i < 10; ++i)
+      RunPredict(inputs, results);
+
+    RunOptions run_options;
+    run_options.set_trace_level(RunOptions::FULL_TRACE);
+    RunMetadata run_metadata;
+    Status status = bundle->session->Run(run_options, inputs, outputs, {},
+                                         &results, &run_metadata);
+    if (!status.ok()) {
+      LOG(ERROR) << "Failed to predict! status = " << status.ToString();
+      exit(-1);
+    }
+
+    std::string tl_str;
+    run_metadata.step_stats().SerializeToString(&tl_str);
+    std::ofstream ofs(args["timeline"].as<std::string>());
+    ofs << tl_str;
+    ofs.close();
+  }
+}
diff --git a/tensorflow/recom/benchmark_throughput.cc b/tensorflow/recom/benchmark_throughput.cc
new file mode 100644
index 00000000000..af16b012860
--- /dev/null
+++ b/tensorflow/recom/benchmark_throughput.cc
@@ -0,0 +1,196 @@
+// Copyright 2023 The RECom Authors. All rights reserved.
+// 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.
+
+#include <unistd.h>
+
+#include <chrono>
+#include <cstdlib>
+#include <fstream>
+#include <iostream>
+#include <string>
+#include <thread>
+#include <unordered_map>
+#include <vector>
+
+#include "absl/strings/str_replace.h"
+#include "cxxopts.hpp"
+#include "tensorflow/core/public/session.h"
+#include "utils.h"
+
+using namespace ::tensorflow;
+using namespace ::tensorflow::benchmark;
+
+int main(int argc, char **argv) {
+  cxxopts::Options options(
+      "benchmark_throughput",
+      "Using pressure test to evaluate the throughput of TF recommendation "
+      "models with mutliple inference threads");
+
+  // clang-format off
+  options.add_options()
+    ("model_path", "Path of the TF saved model (mandatory)", cxxopts::value<std::string>())
+    ("serve_workers", "Number of workers serving the requests concurrently", cxxopts::value<int>()->default_value("1"))
+    ("sla_latency", "Service level agreemnet latency", cxxopts::value<float>()->default_value("100"))
+    ("intra_threads", "TF intra_threads_parallelism (CPU)", cxxopts::value<int>()->default_value("0"))
+    ("inter_threads", "TF inter_threads_parallelism (CPU)", cxxopts::value<int>()->default_value("0"))
+    ("num_iterations", "Number of running iteration", cxxopts::value<int>()->default_value("100"))
+    ("lib_path", "Link a TF addon library", cxxopts::value<std::string>())
+    ("disable_gpu", "Disable the Usage of GPU", cxxopts::value<bool>()->default_value("false"))
+    ("embedding_only", "Only process the embedding parts", cxxopts::value<bool>()->default_value("false"))
+    ("h,help", "Show usage");
+  // clang-format on
+
+  auto args = options.parse(argc, argv);
+  if (args.count("help")) {
+    std::cout << options.help() << std::endl;
+    exit(0);
+  }
+
+  if (!args.count("model_path")) {
+    std::cerr << "ERROR: model_path must be specified!" << std::endl;
+    std::cerr << options.help() << std::endl;
+    exit(-1);
+  }
+
+  const auto &model_path = args["model_path"].as<std::string>();
+  const auto &serve_workers = args["serve_workers"].as<int>();
+  const auto &sla_latency = args["sla_latency"].as<float>();
+  const auto &intra_threads = args["intra_threads"].as<int>();
+  const auto &inter_threads = args["inter_threads"].as<int>();
+  const auto &num_iterations = args["num_iterations"].as<int>();
+  const bool &use_gpu = !args["disable_gpu"].as<bool>();
+
+  const bool &use_lib = args.count("lib_path");
+  const std::string &lib_path =
+      use_lib ? args["lib_path"].as<std::string>() : "";
+
+  LOG(INFO) << "Testing with model: " << model_path;
+  LOG(INFO) << "Testing with serve_workers: " << serve_workers;
+  LOG(INFO) << "Testing with SLA latency: " << sla_latency;
+  LOG(INFO) << "Testing with intra_threads: " << intra_threads;
+  LOG(INFO) << "Testing with inter_threads: " << inter_threads;
+  LOG(INFO) << "Testing with num_iterations: " << num_iterations;
+  LOG(INFO) << "GPU is " << (use_gpu ? "" : "NOT ") << "enabled";
+
+  if (use_lib) {
+    LOG(INFO) << "Testing with library: " << lib_path;
+    LoadOpLibrary(lib_path);
+  }
+
+  std::shared_ptr<SavedModelBundle> bundle;
+  LoadSavedModelWrap(model_path, intra_threads, inter_threads, bundle, use_gpu);
+  const auto &gd = bundle->meta_graph_def.graph_def();
+
+  std::vector<std::string> outputs;
+  if (!args["embedding_only"].as<bool>()) {
+    ExtractGraphOutputs(bundle, outputs);
+  } else {
+    ExtractGraphConcats(gd, outputs);
+  }
+
+  auto RunPredict =
+      [&](const std::vector<std::pair<std::string, Tensor>> &inputs,
+          std::vector<Tensor> &results) {
+        Status status = bundle->session->Run(inputs, outputs, {}, &results);
+        if (!status.ok()) {
+          LOG(ERROR) << "Failed to predict! status = " << status.ToString();
+          exit(-1);
+        }
+      };
+
+  auto RunMultiThreads =
+      [&](const std::vector<std::pair<std::string, Tensor>> &inputs,
+          std::vector<Tensor> &results,
+          int batch_size) -> std::pair<float, int> {
+    // LOG(INFO) << "Fetch nodes: " << absl::StrJoin(outputs, ", ");
+
+    using milli = std::chrono::milliseconds;
+
+    LOG(INFO) << "Start warmup predict";
+
+    auto t1 = std::chrono::high_resolution_clock::now();
+    RunPredict(inputs, results);
+    auto t2 = std::chrono::high_resolution_clock::now();
+
+    int warmup_time = std::chrono::duration_cast<milli>(t2 - t1).count();
+    LOG(INFO) << "Warmup done. Time: " << warmup_time << "ms";
+
+    auto run_thread = [&](int idx, int total) {
+      for (int i = 0; i < num_iterations; ++i) {
+        std::vector<Tensor> res;
+        RunPredict(inputs, res);
+      }
+    };
+
+    auto t3 = std::chrono::high_resolution_clock::now();
+    std::vector<std::thread> threads;
+    for (int i = 0; i < serve_workers; i++) {
+      threads.push_back(std::thread(run_thread, i, serve_workers));
+    }
+    for (auto &thread : threads) {
+      thread.join();
+    }
+    auto t4 = std::chrono::high_resolution_clock::now();
+
+    int total_latency = std::chrono::duration_cast<milli>(t4 - t3).count();
+    float avg_latency = static_cast<float>(total_latency) / num_iterations;
+    int throughput = serve_workers * num_iterations * batch_size /
+                     static_cast<float>(total_latency) * 1000;
+
+    return {avg_latency, throughput};
+  };
+
+  int max_throughput = 0;
+  int max_batch_size = 0;
+  int batch_size = 16;
+  while (true) {
+    std::vector<std::pair<std::string, Tensor>> inputs;
+
+    ConstructGraphInputs(gd, batch_size, inputs);
+
+    std::vector<Tensor> results;
+    auto latency_throughput = RunMultiThreads(inputs, results, batch_size);
+
+    float latency = latency_throughput.first;
+    int throughput = latency_throughput.second;
+    LOG(INFO) << "batch size: " << batch_size << ", "
+              << "avg latency: " << latency << ", "
+              << "throughput: " << throughput;
+
+    if (latency >= sla_latency) {
+      if (batch_size > 512) {
+        break;
+      } else {
+        batch_size += 50;
+      }
+    } else {
+      max_batch_size = batch_size;
+      max_throughput = throughput;
+
+      int increment;
+      if (latency < 50) {
+        increment = batch_size;
+      } else if (latency < 70) {
+        increment = batch_size / 5;
+      } else if (latency < 80) {
+        increment = batch_size / 10;
+      } else if (latency < 90) {
+        increment = batch_size / 30;
+      } else {
+        increment = batch_size / 100;
+      }
+      batch_size += std::max(5, increment);
+    }
+  }
+
+  LOG(INFO) << "[Throughput Result] max_batch_size " << max_batch_size
+            << ", max_throughput " << max_throughput;
+}
\ No newline at end of file
diff --git a/tensorflow/recom/cxxopts.hpp b/tensorflow/recom/cxxopts.hpp
new file mode 100644
index 00000000000..aa9586bfcd6
--- /dev/null
+++ b/tensorflow/recom/cxxopts.hpp
@@ -0,0 +1,2823 @@
+/*
+
+Copyright (c) 2014-2022 Jarryd Beck
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in
+all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+THE SOFTWARE.
+
+*/
+
+// vim: ts=2:sw=2:expandtab
+
+#ifndef CXXOPTS_HPP_INCLUDED
+#define CXXOPTS_HPP_INCLUDED
+
+#include <cstring>
+#include <exception>
+#include <limits>
+#include <initializer_list>
+#include <map>
+#include <memory>
+#include <sstream>
+#include <string>
+#include <unordered_map>
+#include <unordered_set>
+#include <utility>
+#include <vector>
+#include <algorithm>
+#include <locale>
+
+#ifdef CXXOPTS_NO_EXCEPTIONS
+#include <iostream>
+#endif
+
+#if defined(__GNUC__) && !defined(__clang__)
+#  if (__GNUC__ * 10 + __GNUC_MINOR__) < 49
+#    define CXXOPTS_NO_REGEX true
+#  endif
+#endif
+#if defined(_MSC_VER) && !defined(__clang__)
+#define CXXOPTS_LINKONCE_CONST	__declspec(selectany) extern
+#define CXXOPTS_LINKONCE		__declspec(selectany) extern
+#else
+#define CXXOPTS_LINKONCE_CONST	
+#define CXXOPTS_LINKONCE		
+#endif
+
+#ifndef CXXOPTS_NO_REGEX
+#  include <regex>
+#endif  // CXXOPTS_NO_REGEX
+
+// Nonstandard before C++17, which is coincidentally what we also need for <optional>
+#ifdef __has_include
+#  if __has_include(<optional>)
+#    include <optional>
+#    ifdef __cpp_lib_optional
+#      define CXXOPTS_HAS_OPTIONAL
+#    endif
+#  endif
+#endif
+
+#if __cplusplus >= 201603L
+#define CXXOPTS_NODISCARD [[nodiscard]]
+#else
+#define CXXOPTS_NODISCARD
+#endif
+
+#ifndef CXXOPTS_VECTOR_DELIMITER
+#define CXXOPTS_VECTOR_DELIMITER ','
+#endif
+
+#define CXXOPTS__VERSION_MAJOR 3
+#define CXXOPTS__VERSION_MINOR 1
+#define CXXOPTS__VERSION_PATCH 1
+
+#if (__GNUC__ < 10 || (__GNUC__ == 10 && __GNUC_MINOR__ < 1)) && __GNUC__ >= 6
+  #define CXXOPTS_NULL_DEREF_IGNORE
+#endif
+
+#if defined(__GNUC__)
+#define DO_PRAGMA(x) _Pragma(#x)
+#define CXXOPTS_DIAGNOSTIC_PUSH DO_PRAGMA(GCC diagnostic push)
+#define CXXOPTS_DIAGNOSTIC_POP DO_PRAGMA(GCC diagnostic pop)
+#define CXXOPTS_IGNORE_WARNING(x) DO_PRAGMA(GCC diagnostic ignored x)
+#else
+// define other compilers here if needed
+#define CXXOPTS_DIAGNOSTIC_PUSH
+#define CXXOPTS_DIAGNOSTIC_POP
+#define CXXOPTS_IGNORE_WARNING(x)
+#endif
+
+#ifdef CXXOPTS_NO_RTTI
+#define CXXOPTS_RTTI_CAST static_cast
+#else
+#define CXXOPTS_RTTI_CAST dynamic_cast
+#endif
+
+namespace cxxopts {
+static constexpr struct {
+  uint8_t major, minor, patch;
+} version = {
+  CXXOPTS__VERSION_MAJOR,
+  CXXOPTS__VERSION_MINOR,
+  CXXOPTS__VERSION_PATCH
+};
+} // namespace cxxopts
+
+//when we ask cxxopts to use Unicode, help strings are processed using ICU,
+//which results in the correct lengths being computed for strings when they
+//are formatted for the help output
+//it is necessary to make sure that <unicode/unistr.h> can be found by the
+//compiler, and that icu-uc is linked in to the binary.
+
+#ifdef CXXOPTS_USE_UNICODE
+#include <unicode/unistr.h>
+
+namespace cxxopts {
+
+using String = icu::UnicodeString;
+
+inline
+String
+toLocalString(std::string s)
+{
+  return icu::UnicodeString::fromUTF8(std::move(s));
+}
+
+// GNU GCC with -Weffc++ will issue a warning regarding the upcoming class, we want to silence it:
+// warning: base class 'class std::enable_shared_from_this<cxxopts::Value>' has accessible non-virtual destructor
+CXXOPTS_DIAGNOSTIC_PUSH
+CXXOPTS_IGNORE_WARNING("-Wnon-virtual-dtor")
+// This will be ignored under other compilers like LLVM clang.
+class UnicodeStringIterator
+{
+  public:
+
+  using iterator_category = std::forward_iterator_tag;
+  using value_type = int32_t;
+  using difference_type = std::ptrdiff_t;
+  using pointer = value_type*;
+  using reference = value_type&;
+
+  UnicodeStringIterator(const icu::UnicodeString* string, int32_t pos)
+  : s(string)
+  , i(pos)
+  {
+  }
+
+  value_type
+  operator*() const
+  {
+    return s->char32At(i);
+  }
+
+  bool
+  operator==(const UnicodeStringIterator& rhs) const
+  {
+    return s == rhs.s && i == rhs.i;
+  }
+
+  bool
+  operator!=(const UnicodeStringIterator& rhs) const
+  {
+    return !(*this == rhs);
+  }
+
+  UnicodeStringIterator&
+  operator++()
+  {
+    ++i;
+    return *this;
+  }
+
+  UnicodeStringIterator
+  operator+(int32_t v)
+  {
+    return UnicodeStringIterator(s, i + v);
+  }
+
+  private:
+  const icu::UnicodeString* s;
+  int32_t i;
+};
+CXXOPTS_DIAGNOSTIC_POP
+
+inline
+String&
+stringAppend(String&s, String a)
+{
+  return s.append(std::move(a));
+}
+
+inline
+String&
+stringAppend(String& s, std::size_t n, UChar32 c)
+{
+  for (std::size_t i = 0; i != n; ++i)
+  {
+    s.append(c);
+  }
+
+  return s;
+}
+
+template <typename Iterator>
+String&
+stringAppend(String& s, Iterator begin, Iterator end)
+{
+  while (begin != end)
+  {
+    s.append(*begin);
+    ++begin;
+  }
+
+  return s;
+}
+
+inline
+size_t
+stringLength(const String& s)
+{
+  return static_cast<size_t>(s.length());
+}
+
+inline
+std::string
+toUTF8String(const String& s)
+{
+  std::string result;
+  s.toUTF8String(result);
+
+  return result;
+}
+
+inline
+bool
+empty(const String& s)
+{
+  return s.isEmpty();
+}
+
+} // namespace cxxopts
+
+namespace std {
+
+inline
+cxxopts::UnicodeStringIterator
+begin(const icu::UnicodeString& s)
+{
+  return cxxopts::UnicodeStringIterator(&s, 0);
+}
+
+inline
+cxxopts::UnicodeStringIterator
+end(const icu::UnicodeString& s)
+{
+  return cxxopts::UnicodeStringIterator(&s, s.length());
+}
+
+} // namespace std
+
+//ifdef CXXOPTS_USE_UNICODE
+#else
+
+namespace cxxopts {
+
+using String = std::string;
+
+template <typename T>
+T
+toLocalString(T&& t)
+{
+  return std::forward<T>(t);
+}
+
+inline
+std::size_t
+stringLength(const String& s)
+{
+  return s.length();
+}
+
+inline
+String&
+stringAppend(String&s, const String& a)
+{
+  return s.append(a);
+}
+
+inline
+String&
+stringAppend(String& s, std::size_t n, char c)
+{
+  return s.append(n, c);
+}
+
+template <typename Iterator>
+String&
+stringAppend(String& s, Iterator begin, Iterator end)
+{
+  return s.append(begin, end);
+}
+
+template <typename T>
+std::string
+toUTF8String(T&& t)
+{
+  return std::forward<T>(t);
+}
+
+inline
+bool
+empty(const std::string& s)
+{
+  return s.empty();
+}
+
+} // namespace cxxopts
+
+//ifdef CXXOPTS_USE_UNICODE
+#endif
+
+namespace cxxopts {
+
+namespace {
+CXXOPTS_LINKONCE_CONST std::string LQUOTE("\'");
+CXXOPTS_LINKONCE_CONST std::string RQUOTE("\'");
+} // namespace
+
+// GNU GCC with -Weffc++ will issue a warning regarding the upcoming class, we
+// want to silence it: warning: base class 'class
+// std::enable_shared_from_this<cxxopts::Value>' has accessible non-virtual
+// destructor This will be ignored under other compilers like LLVM clang.
+CXXOPTS_DIAGNOSTIC_PUSH
+CXXOPTS_IGNORE_WARNING("-Wnon-virtual-dtor")
+
+// some older versions of GCC warn under this warning
+CXXOPTS_IGNORE_WARNING("-Weffc++")
+class Value : public std::enable_shared_from_this<Value>
+{
+  public:
+
+  virtual ~Value() = default;
+
+  virtual
+  std::shared_ptr<Value>
+  clone() const = 0;
+
+  virtual void
+  parse(const std::string& text) const = 0;
+
+  virtual void
+  parse() const = 0;
+
+  virtual bool
+  has_default() const = 0;
+
+  virtual bool
+  is_container() const = 0;
+
+  virtual bool
+  has_implicit() const = 0;
+
+  virtual std::string
+  get_default_value() const = 0;
+
+  virtual std::string
+  get_implicit_value() const = 0;
+
+  virtual std::shared_ptr<Value>
+  default_value(const std::string& value) = 0;
+
+  virtual std::shared_ptr<Value>
+  implicit_value(const std::string& value) = 0;
+
+  virtual std::shared_ptr<Value>
+  no_implicit_value() = 0;
+
+  virtual bool
+  is_boolean() const = 0;
+};
+
+CXXOPTS_DIAGNOSTIC_POP
+
+namespace exceptions {
+
+class exception : public std::exception
+{
+  public:
+  explicit exception(std::string  message)
+  : m_message(std::move(message))
+  {
+  }
+
+  CXXOPTS_NODISCARD
+  const char*
+  what() const noexcept override
+  {
+    return m_message.c_str();
+  }
+
+  private:
+  std::string m_message;
+};
+
+class specification : public exception
+{
+  public:
+
+  explicit specification(const std::string& message)
+  : exception(message)
+  {
+  }
+};
+
+class parsing : public exception
+{
+  public:
+  explicit parsing(const std::string& message)
+  : exception(message)
+  {
+  }
+};
+
+class option_already_exists : public specification
+{
+  public:
+  explicit option_already_exists(const std::string& option)
+  : specification("Option " + LQUOTE + option + RQUOTE + " already exists")
+  {
+  }
+};
+
+class invalid_option_format : public specification
+{
+  public:
+  explicit invalid_option_format(const std::string& format)
+  : specification("Invalid option format " + LQUOTE + format + RQUOTE)
+  {
+  }
+};
+
+class invalid_option_syntax : public parsing {
+  public:
+  explicit invalid_option_syntax(const std::string& text)
+  : parsing("Argument " + LQUOTE + text + RQUOTE +
+            " starts with a - but has incorrect syntax")
+  {
+  }
+};
+
+class no_such_option : public parsing
+{
+  public:
+  explicit no_such_option(const std::string& option)
+  : parsing("Option " + LQUOTE + option + RQUOTE + " does not exist")
+  {
+  }
+};
+
+class missing_argument : public parsing
+{
+  public:
+  explicit missing_argument(const std::string& option)
+  : parsing(
+      "Option " + LQUOTE + option + RQUOTE + " is missing an argument"
+    )
+  {
+  }
+};
+
+class option_requires_argument : public parsing
+{
+  public:
+  explicit option_requires_argument(const std::string& option)
+  : parsing(
+      "Option " + LQUOTE + option + RQUOTE + " requires an argument"
+    )
+  {
+  }
+};
+
+class gratuitous_argument_for_option : public parsing
+{
+  public:
+  gratuitous_argument_for_option
+  (
+    const std::string& option,
+    const std::string& arg
+  )
+  : parsing(
+      "Option " + LQUOTE + option + RQUOTE +
+      " does not take an argument, but argument " +
+      LQUOTE + arg + RQUOTE + " given"
+    )
+  {
+  }
+};
+
+class requested_option_not_present : public parsing
+{
+  public:
+  explicit requested_option_not_present(const std::string& option)
+  : parsing("Option " + LQUOTE + option + RQUOTE + " not present")
+  {
+  }
+};
+
+class option_has_no_value : public exception
+{
+  public:
+  explicit option_has_no_value(const std::string& option)
+  : exception(
+      !option.empty() ?
+      ("Option " + LQUOTE + option + RQUOTE + " has no value") :
+      "Option has no value")
+  {
+  }
+};
+
+class incorrect_argument_type : public parsing
+{
+  public:
+  explicit incorrect_argument_type
+  (
+    const std::string& arg
+  )
+  : parsing(
+      "Argument " + LQUOTE + arg + RQUOTE + " failed to parse"
+    )
+  {
+  }
+};
+
+} // namespace exceptions
+
+
+template <typename T>
+void throw_or_mimic(const std::string& text)
+{
+  static_assert(std::is_base_of<std::exception, T>::value,
+                "throw_or_mimic only works on std::exception and "
+                "deriving classes");
+
+#ifndef CXXOPTS_NO_EXCEPTIONS
+  // If CXXOPTS_NO_EXCEPTIONS is not defined, just throw
+  throw T{text};
+#else
+  // Otherwise manually instantiate the exception, print what() to stderr,
+  // and exit
+  T exception{text};
+  std::cerr << exception.what() << std::endl;
+  std::exit(EXIT_FAILURE);
+#endif
+}
+
+using OptionNames = std::vector<std::string>;
+
+namespace values {
+
+namespace parser_tool {
+
+struct IntegerDesc
+{
+  std::string negative = "";
+  std::string base     = "";
+  std::string value    = "";
+};
+struct ArguDesc {
+  std::string arg_name  = "";
+  bool        grouping  = false;
+  bool        set_value = false;
+  std::string value     = "";
+};
+
+#ifdef CXXOPTS_NO_REGEX
+inline IntegerDesc SplitInteger(const std::string &text)
+{
+  if (text.empty())
+  {
+    throw_or_mimic<exceptions::incorrect_argument_type>(text);
+  }
+  IntegerDesc desc;
+  const char *pdata = text.c_str();
+  if (*pdata == '-')
+  {
+    pdata += 1;
+    desc.negative = "-";
+  }
+  if (strncmp(pdata, "0x", 2) == 0)
+  {
+    pdata += 2;
+    desc.base = "0x";
+  }
+  if (*pdata != '\0')
+  {
+    desc.value = std::string(pdata);
+  }
+  else
+  {
+    throw_or_mimic<exceptions::incorrect_argument_type>(text);
+  }
+  return desc;
+}
+
+inline bool IsTrueText(const std::string &text)
+{
+  const char *pdata = text.c_str();
+  if (*pdata == 't' || *pdata == 'T')
+  {
+    pdata += 1;
+    if (strncmp(pdata, "rue\0", 4) == 0)
+    {
+      return true;
+    }
+  }
+  else if (strncmp(pdata, "1\0", 2) == 0)
+  {
+    return true;
+  }
+  return false;
+}
+
+inline bool IsFalseText(const std::string &text)
+{
+  const char *pdata = text.c_str();
+  if (*pdata == 'f' || *pdata == 'F')
+  {
+    pdata += 1;
+    if (strncmp(pdata, "alse\0", 5) == 0)
+    {
+      return true;
+    }
+  }
+  else if (strncmp(pdata, "0\0", 2) == 0)
+  {
+    return true;
+  }
+  return false;
+}
+
+inline OptionNames split_option_names(const std::string &text)
+{
+  OptionNames split_names;
+
+  std::string::size_type token_start_pos = 0;
+  auto length = text.length();
+
+  if (length == 0)
+  {
+    throw_or_mimic<exceptions::invalid_option_format>(text);
+  }
+
+  while (token_start_pos < length) {
+    const auto &npos = std::string::npos;
+    auto next_non_space_pos = text.find_first_not_of(' ', token_start_pos);
+    if (next_non_space_pos == npos) {
+      throw_or_mimic<exceptions::invalid_option_format>(text);
+    }
+    token_start_pos = next_non_space_pos;
+    auto next_delimiter_pos = text.find(',', token_start_pos);
+    if (next_delimiter_pos == token_start_pos) {
+      throw_or_mimic<exceptions::invalid_option_format>(text);
+    }
+    if (next_delimiter_pos == npos) {
+      next_delimiter_pos = length;
+    }
+    auto token_length = next_delimiter_pos - token_start_pos;
+    // validate the token itself matches the regex /([:alnum:][-_[:alnum:]]*/
+    {
+      const char* option_name_valid_chars =
+        "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
+        "abcdefghijklmnopqrstuvwxyz"
+        "0123456789"
+        "_-.?";
+
+      if (!std::isalnum(text[token_start_pos], std::locale::classic()) ||
+          text.find_first_not_of(option_name_valid_chars, token_start_pos) < next_delimiter_pos) {
+        throw_or_mimic<exceptions::invalid_option_format>(text);
+      }
+    }
+    split_names.emplace_back(text.substr(token_start_pos, token_length));
+    token_start_pos = next_delimiter_pos + 1;
+  }
+  return split_names;
+}
+
+inline ArguDesc ParseArgument(const char *arg, bool &matched)
+{
+  ArguDesc argu_desc;
+  const char *pdata = arg;
+  matched = false;
+  if (strncmp(pdata, "--", 2) == 0)
+  {
+    pdata += 2;
+    if (isalnum(*pdata, std::locale::classic()))
+    {
+      argu_desc.arg_name.push_back(*pdata);
+      pdata += 1;
+      while (isalnum(*pdata, std::locale::classic()) || *pdata == '-' || *pdata == '_')
+      {
+        argu_desc.arg_name.push_back(*pdata);
+        pdata += 1;
+      }
+      if (argu_desc.arg_name.length() > 1)
+      {
+        if (*pdata == '=')
+        {
+          argu_desc.set_value = true;
+          pdata += 1;
+          if (*pdata != '\0')
+          {
+            argu_desc.value = std::string(pdata);
+          }
+          matched = true;
+        }
+        else if (*pdata == '\0')
+        {
+          matched = true;
+        }
+      }
+    }
+  }
+  else if (strncmp(pdata, "-", 1) == 0)
+  {
+    pdata += 1;
+    argu_desc.grouping = true;
+    while (isalnum(*pdata, std::locale::classic()))
+    {
+      argu_desc.arg_name.push_back(*pdata);
+      pdata += 1;
+    }
+    matched = !argu_desc.arg_name.empty() && *pdata == '\0';
+  }
+  return argu_desc;
+}
+
+#else  // CXXOPTS_NO_REGEX
+
+namespace {
+CXXOPTS_LINKONCE
+std::basic_regex<char> integer_pattern
+  ("(-)?(0x)?([0-9a-zA-Z]+)|((0x)?0)");
+CXXOPTS_LINKONCE
+std::basic_regex<char> truthy_pattern
+  ("(t|T)(rue)?|1");
+CXXOPTS_LINKONCE
+std::basic_regex<char> falsy_pattern
+  ("(f|F)(alse)?|0");
+CXXOPTS_LINKONCE
+std::basic_regex<char> option_matcher
+  ("--([[:alnum:]][-_[:alnum:]\\.]+)(=(.*))?|-([[:alnum:]].*)");
+CXXOPTS_LINKONCE
+std::basic_regex<char> option_specifier
+  ("([[:alnum:]][-_[:alnum:]\\.]*)(,[ ]*[[:alnum:]][-_[:alnum:]]*)*");
+CXXOPTS_LINKONCE
+std::basic_regex<char> option_specifier_separator(", *");
+
+} // namespace
+
+inline IntegerDesc SplitInteger(const std::string &text)
+{
+  std::smatch match;
+  std::regex_match(text, match, integer_pattern);
+
+  if (match.length() == 0)
+  {
+    throw_or_mimic<exceptions::incorrect_argument_type>(text);
+  }
+
+  IntegerDesc desc;
+  desc.negative = match[1];
+  desc.base = match[2];
+  desc.value = match[3];
+
+  if (match.length(4) > 0)
+  {
+    desc.base = match[5];
+    desc.value = "0";
+    return desc;
+  }
+
+  return desc;
+}
+
+inline bool IsTrueText(const std::string &text)
+{
+  std::smatch result;
+  std::regex_match(text, result, truthy_pattern);
+  return !result.empty();
+}
+
+inline bool IsFalseText(const std::string &text)
+{
+  std::smatch result;
+  std::regex_match(text, result, falsy_pattern);
+  return !result.empty();
+}
+
+// Gets the option names specified via a single, comma-separated string,
+// and returns the separate, space-discarded, non-empty names
+// (without considering which or how many are single-character)
+inline OptionNames split_option_names(const std::string &text)
+{
+  if (!std::regex_match(text.c_str(), option_specifier))
+  {
+    throw_or_mimic<exceptions::invalid_option_format>(text);
+  }
+
+  OptionNames split_names;
+
+  constexpr int use_non_matches { -1 };
+  auto token_iterator = std::sregex_token_iterator(
+    text.begin(), text.end(), option_specifier_separator, use_non_matches);
+  std::copy(token_iterator, std::sregex_token_iterator(), std::back_inserter(split_names));
+  return split_names;
+}
+
+inline ArguDesc ParseArgument(const char *arg, bool &matched)
+{
+  std::match_results<const char*> result;
+  std::regex_match(arg, result, option_matcher);
+  matched = !result.empty();
+
+  ArguDesc argu_desc;
+  if (matched) {
+    argu_desc.arg_name = result[1].str();
+    argu_desc.set_value = result[2].length() > 0;
+    argu_desc.value = result[3].str();
+    if (result[4].length() > 0)
+    {
+      argu_desc.grouping = true;
+      argu_desc.arg_name = result[4].str();
+    }
+  }
+
+  return argu_desc;
+}
+
+#endif  // CXXOPTS_NO_REGEX
+#undef CXXOPTS_NO_REGEX
+} // namespace parser_tool
+
+namespace detail {
+
+template <typename T, bool B>
+struct SignedCheck;
+
+template <typename T>
+struct SignedCheck<T, true>
+{
+  template <typename U>
+  void
+  operator()(bool negative, U u, const std::string& text)
+  {
+    if (negative)
+    {
+      if (u > static_cast<U>((std::numeric_limits<T>::min)()))
+      {
+        throw_or_mimic<exceptions::incorrect_argument_type>(text);
+      }
+    }
+    else
+    {
+      if (u > static_cast<U>((std::numeric_limits<T>::max)()))
+      {
+        throw_or_mimic<exceptions::incorrect_argument_type>(text);
+      }
+    }
+  }
+};
+
+template <typename T>
+struct SignedCheck<T, false>
+{
+  template <typename U>
+  void
+  operator()(bool, U, const std::string&) const {}
+};
+
+template <typename T, typename U>
+void
+check_signed_range(bool negative, U value, const std::string& text)
+{
+  SignedCheck<T, std::numeric_limits<T>::is_signed>()(negative, value, text);
+}
+
+} // namespace detail
+
+template <typename R, typename T>
+void
+checked_negate(R& r, T&& t, const std::string&, std::true_type)
+{
+  // if we got to here, then `t` is a positive number that fits into
+  // `R`. So to avoid MSVC C4146, we first cast it to `R`.
+  // See https://github.com/jarro2783/cxxopts/issues/62 for more details.
+  r = static_cast<R>(-static_cast<R>(t-1)-1);
+}
+
+template <typename R, typename T>
+void
+checked_negate(R&, T&&, const std::string& text, std::false_type)
+{
+  throw_or_mimic<exceptions::incorrect_argument_type>(text);
+}
+
+template <typename T>
+void
+integer_parser(const std::string& text, T& value)
+{
+  parser_tool::IntegerDesc int_desc = parser_tool::SplitInteger(text);
+
+  using US = typename std::make_unsigned<T>::type;
+  constexpr bool is_signed = std::numeric_limits<T>::is_signed;
+
+  const bool          negative    = int_desc.negative.length() > 0;
+  const uint8_t       base        = int_desc.base.length() > 0 ? 16 : 10;
+  const std::string & value_match = int_desc.value;
+
+  US result = 0;
+
+  for (char ch : value_match)
+  {
+    US digit = 0;
+
+    if (ch >= '0' && ch <= '9')
+    {
+      digit = static_cast<US>(ch - '0');
+    }
+    else if (base == 16 && ch >= 'a' && ch <= 'f')
+    {
+      digit = static_cast<US>(ch - 'a' + 10);
+    }
+    else if (base == 16 && ch >= 'A' && ch <= 'F')
+    {
+      digit = static_cast<US>(ch - 'A' + 10);
+    }
+    else
+    {
+      throw_or_mimic<exceptions::incorrect_argument_type>(text);
+    }
+
+    const US next = static_cast<US>(result * base + digit);
+    if (result > next)
+    {
+      throw_or_mimic<exceptions::incorrect_argument_type>(text);
+    }
+
+    result = next;
+  }
+
+  detail::check_signed_range<T>(negative, result, text);
+
+  if (negative)
+  {
+    checked_negate<T>(value, result, text, std::integral_constant<bool, is_signed>());
+  }
+  else
+  {
+    value = static_cast<T>(result);
+  }
+}
+
+template <typename T>
+void stringstream_parser(const std::string& text, T& value)
+{
+  std::stringstream in(text);
+  in >> value;
+  if (!in) {
+    throw_or_mimic<exceptions::incorrect_argument_type>(text);
+  }
+}
+
+template <typename T,
+         typename std::enable_if<std::is_integral<T>::value>::type* = nullptr
+         >
+void parse_value(const std::string& text, T& value)
+{
+    integer_parser(text, value);
+}
+
+inline
+void
+parse_value(const std::string& text, bool& value)
+{
+  if (parser_tool::IsTrueText(text))
+  {
+    value = true;
+    return;
+  }
+
+  if (parser_tool::IsFalseText(text))
+  {
+    value = false;
+    return;
+  }
+
+  throw_or_mimic<exceptions::incorrect_argument_type>(text);
+}
+
+inline
+void
+parse_value(const std::string& text, std::string& value)
+{
+  value = text;
+}
+
+// The fallback parser. It uses the stringstream parser to parse all types
+// that have not been overloaded explicitly.  It has to be placed in the
+// source code before all other more specialized templates.
+template <typename T,
+         typename std::enable_if<!std::is_integral<T>::value>::type* = nullptr
+         >
+void
+parse_value(const std::string& text, T& value) {
+  stringstream_parser(text, value);
+}
+
+template <typename T>
+void
+parse_value(const std::string& text, std::vector<T>& value)
+{
+  if (text.empty()) {
+    T v;
+    parse_value(text, v);
+    value.emplace_back(std::move(v));
+    return;
+  }
+  std::stringstream in(text);
+  std::string token;
+  while(!in.eof() && std::getline(in, token, CXXOPTS_VECTOR_DELIMITER)) {
+    T v;
+    parse_value(token, v);
+    value.emplace_back(std::move(v));
+  }
+}
+
+#ifdef CXXOPTS_HAS_OPTIONAL
+template <typename T>
+void
+parse_value(const std::string& text, std::optional<T>& value)
+{
+  T result;
+  parse_value(text, result);
+  value = std::move(result);
+}
+#endif
+
+inline
+void parse_value(const std::string& text, char& c)
+{
+  if (text.length() != 1)
+  {
+    throw_or_mimic<exceptions::incorrect_argument_type>(text);
+  }
+
+  c = text[0];
+}
+
+template <typename T>
+struct type_is_container
+{
+  static constexpr bool value = false;
+};
+
+template <typename T>
+struct type_is_container<std::vector<T>>
+{
+  static constexpr bool value = true;
+};
+
+template <typename T>
+class abstract_value : public Value
+{
+  using Self = abstract_value<T>;
+
+  public:
+  abstract_value()
+  : m_result(std::make_shared<T>())
+  , m_store(m_result.get())
+  {
+  }
+
+  explicit abstract_value(T* t)
+  : m_store(t)
+  {
+  }
+
+  ~abstract_value() override = default;
+
+  abstract_value& operator=(const abstract_value&) = default;
+
+  abstract_value(const abstract_value& rhs)
+  {
+    if (rhs.m_result)
+    {
+      m_result = std::make_shared<T>();
+      m_store = m_result.get();
+    }
+    else
+    {
+      m_store = rhs.m_store;
+    }
+
+    m_default = rhs.m_default;
+    m_implicit = rhs.m_implicit;
+    m_default_value = rhs.m_default_value;
+    m_implicit_value = rhs.m_implicit_value;
+  }
+
+  void
+  parse(const std::string& text) const override
+  {
+    parse_value(text, *m_store);
+  }
+
+  bool
+  is_container() const override
+  {
+    return type_is_container<T>::value;
+  }
+
+  void
+  parse() const override
+  {
+    parse_value(m_default_value, *m_store);
+  }
+
+  bool
+  has_default() const override
+  {
+    return m_default;
+  }
+
+  bool
+  has_implicit() const override
+  {
+    return m_implicit;
+  }
+
+  std::shared_ptr<Value>
+  default_value(const std::string& value) override
+  {
+    m_default = true;
+    m_default_value = value;
+    return shared_from_this();
+  }
+
+  std::shared_ptr<Value>
+  implicit_value(const std::string& value) override
+  {
+    m_implicit = true;
+    m_implicit_value = value;
+    return shared_from_this();
+  }
+
+  std::shared_ptr<Value>
+  no_implicit_value() override
+  {
+    m_implicit = false;
+    return shared_from_this();
+  }
+
+  std::string
+  get_default_value() const override
+  {
+    return m_default_value;
+  }
+
+  std::string
+  get_implicit_value() const override
+  {
+    return m_implicit_value;
+  }
+
+  bool
+  is_boolean() const override
+  {
+    return std::is_same<T, bool>::value;
+  }
+
+  const T&
+  get() const
+  {
+    if (m_store == nullptr)
+    {
+      return *m_result;
+    }
+    return *m_store;
+  }
+
+  protected:
+  std::shared_ptr<T> m_result{};
+  T* m_store{};
+
+  bool m_default = false;
+  bool m_implicit = false;
+
+  std::string m_default_value{};
+  std::string m_implicit_value{};
+};
+
+template <typename T>
+class standard_value : public abstract_value<T>
+{
+  public:
+  using abstract_value<T>::abstract_value;
+
+  CXXOPTS_NODISCARD
+  std::shared_ptr<Value>
+  clone() const override
+  {
+    return std::make_shared<standard_value<T>>(*this);
+  }
+};
+
+template <>
+class standard_value<bool> : public abstract_value<bool>
+{
+  public:
+  ~standard_value() override = default;
+
+  standard_value()
+  {
+    set_default_and_implicit();
+  }
+
+  explicit standard_value(bool* b)
+  : abstract_value(b)
+  {
+    m_implicit = true;
+    m_implicit_value = "true";
+  }
+
+  std::shared_ptr<Value>
+  clone() const override
+  {
+    return std::make_shared<standard_value<bool>>(*this);
+  }
+
+  private:
+
+  void
+  set_default_and_implicit()
+  {
+    m_default = true;
+    m_default_value = "false";
+    m_implicit = true;
+    m_implicit_value = "true";
+  }
+};
+
+} // namespace values
+
+template <typename T>
+std::shared_ptr<Value>
+value()
+{
+  return std::make_shared<values::standard_value<T>>();
+}
+
+template <typename T>
+std::shared_ptr<Value>
+value(T& t)
+{
+  return std::make_shared<values::standard_value<T>>(&t);
+}
+
+class OptionAdder;
+
+CXXOPTS_NODISCARD
+inline
+const std::string&
+first_or_empty(const OptionNames& long_names)
+{
+  static const std::string empty{""};
+  return long_names.empty() ? empty : long_names.front();
+}
+
+class OptionDetails
+{
+  public:
+  OptionDetails
+  (
+    std::string short_,
+    OptionNames long_,
+    String desc,
+    std::shared_ptr<const Value> val
+  )
+  : m_short(std::move(short_))
+  , m_long(std::move(long_))
+  , m_desc(std::move(desc))
+  , m_value(std::move(val))
+  , m_count(0)
+  {
+    m_hash = std::hash<std::string>{}(first_long_name() + m_short);
+  }
+
+  OptionDetails(const OptionDetails& rhs)
+  : m_desc(rhs.m_desc)
+  , m_value(rhs.m_value->clone())
+  , m_count(rhs.m_count)
+  {
+  }
+
+  OptionDetails(OptionDetails&& rhs) = default;
+
+  CXXOPTS_NODISCARD
+  const String&
+  description() const
+  {
+    return m_desc;
+  }
+
+  CXXOPTS_NODISCARD
+  const Value&
+  value() const {
+      return *m_value;
+  }
+
+  CXXOPTS_NODISCARD
+  std::shared_ptr<Value>
+  make_storage() const
+  {
+    return m_value->clone();
+  }
+
+  CXXOPTS_NODISCARD
+  const std::string&
+  short_name() const
+  {
+    return m_short;
+  }
+
+  CXXOPTS_NODISCARD
+  const std::string&
+  first_long_name() const
+  {
+    return first_or_empty(m_long);
+  }
+
+  CXXOPTS_NODISCARD
+  const std::string&
+  essential_name() const
+  {
+    return m_long.empty() ? m_short : m_long.front();
+  }
+
+  CXXOPTS_NODISCARD
+  const OptionNames &
+  long_names() const
+  {
+    return m_long;
+  }
+
+  std::size_t
+  hash() const
+  {
+    return m_hash;
+  }
+
+  private:
+  std::string m_short{};
+  OptionNames m_long{};
+  String m_desc{};
+  std::shared_ptr<const Value> m_value{};
+  int m_count;
+
+  std::size_t m_hash{};
+};
+
+struct HelpOptionDetails
+{
+  std::string s;
+  OptionNames l;
+  String desc;
+  bool has_default;
+  std::string default_value;
+  bool has_implicit;
+  std::string implicit_value;
+  std::string arg_help;
+  bool is_container;
+  bool is_boolean;
+};
+
+struct HelpGroupDetails
+{
+  std::string name{};
+  std::string description{};
+  std::vector<HelpOptionDetails> options{};
+};
+
+class OptionValue
+{
+  public:
+  void
+  parse
+  (
+    const std::shared_ptr<const OptionDetails>& details,
+    const std::string& text
+  )
+  {
+    ensure_value(details);
+    ++m_count;
+    m_value->parse(text);
+    m_long_names = &details->long_names();
+  }
+
+  void
+  parse_default(const std::shared_ptr<const OptionDetails>& details)
+  {
+    ensure_value(details);
+    m_default = true;
+    m_long_names = &details->long_names();
+    m_value->parse();
+  }
+
+  void
+  parse_no_value(const std::shared_ptr<const OptionDetails>& details)
+  {
+    m_long_names = &details->long_names();
+  }
+
+#if defined(CXXOPTS_NULL_DEREF_IGNORE)
+CXXOPTS_DIAGNOSTIC_PUSH
+CXXOPTS_IGNORE_WARNING("-Wnull-dereference")
+#endif
+
+  CXXOPTS_NODISCARD
+  std::size_t
+  count() const noexcept
+  {
+    return m_count;
+  }
+
+#if defined(CXXOPTS_NULL_DEREF_IGNORE)
+CXXOPTS_DIAGNOSTIC_POP
+#endif
+
+  // TODO: maybe default options should count towards the number of arguments
+  CXXOPTS_NODISCARD
+  bool
+  has_default() const noexcept
+  {
+    return m_default;
+  }
+
+  template <typename T>
+  const T&
+  as() const
+  {
+    if (m_value == nullptr) {
+        throw_or_mimic<exceptions::option_has_no_value>(
+            m_long_names == nullptr ? "" : first_or_empty(*m_long_names));
+    }
+
+    return CXXOPTS_RTTI_CAST<const values::standard_value<T>&>(*m_value).get();
+  }
+
+  private:
+  void
+  ensure_value(const std::shared_ptr<const OptionDetails>& details)
+  {
+    if (m_value == nullptr)
+    {
+      m_value = details->make_storage();
+    }
+  }
+
+
+  const OptionNames * m_long_names = nullptr;
+  // Holding this pointer is safe, since OptionValue's only exist in key-value pairs,
+  // where the key has the string we point to.
+  std::shared_ptr<Value> m_value{};
+  std::size_t m_count = 0;
+  bool m_default = false;
+};
+
+class KeyValue
+{
+  public:
+  KeyValue(std::string key_, std::string value_) noexcept
+  : m_key(std::move(key_))
+  , m_value(std::move(value_))
+  {
+  }
+
+  CXXOPTS_NODISCARD
+  const std::string&
+  key() const
+  {
+    return m_key;
+  }
+
+  CXXOPTS_NODISCARD
+  const std::string&
+  value() const
+  {
+    return m_value;
+  }
+
+  template <typename T>
+  T
+  as() const
+  {
+    T result;
+    values::parse_value(m_value, result);
+    return result;
+  }
+
+  private:
+  std::string m_key;
+  std::string m_value;
+};
+
+using ParsedHashMap = std::unordered_map<std::size_t, OptionValue>;
+using NameHashMap = std::unordered_map<std::string, std::size_t>;
+
+class ParseResult
+{
+  public:
+  class Iterator
+  {
+    public:
+    using iterator_category = std::forward_iterator_tag;
+    using value_type = KeyValue;
+    using difference_type = void;
+    using pointer = const KeyValue*;
+    using reference = const KeyValue&;
+
+    Iterator() = default;
+    Iterator(const Iterator&) = default;
+
+// GCC complains about m_iter not being initialised in the member
+// initializer list 
+CXXOPTS_DIAGNOSTIC_PUSH
+CXXOPTS_IGNORE_WARNING("-Weffc++")
+    Iterator(const ParseResult *pr, bool end=false)
+    : m_pr(pr)
+    {
+      if (end)
+      {
+        m_sequential = false;
+        m_iter = m_pr->m_defaults.end();
+      }
+      else
+      {
+        m_sequential = true;
+        m_iter = m_pr->m_sequential.begin();
+
+        if (m_iter == m_pr->m_sequential.end())
+        {
+          m_sequential = false;
+          m_iter = m_pr->m_defaults.begin();
+        }
+      }
+    }
+CXXOPTS_DIAGNOSTIC_POP
+
+    Iterator& operator++()
+    {
+      ++m_iter;
+      if(m_sequential && m_iter == m_pr->m_sequential.end())
+      {
+        m_sequential = false;
+        m_iter = m_pr->m_defaults.begin();
+        return *this;
+      }
+      return *this;
+    }
+
+    Iterator operator++(int)
+    {
+      Iterator retval = *this;
+      ++(*this);
+      return retval;
+    }
+
+    bool operator==(const Iterator& other) const
+    {
+      return (m_sequential == other.m_sequential) && (m_iter == other.m_iter);
+    }
+
+    bool operator!=(const Iterator& other) const
+    {
+      return !(*this == other);
+    }
+
+    const KeyValue& operator*()
+    {
+      return *m_iter;
+    }
+
+    const KeyValue* operator->()
+    {
+      return m_iter.operator->();
+    }
+
+    private:
+    const ParseResult* m_pr;
+    std::vector<KeyValue>::const_iterator m_iter;
+    bool m_sequential = true;
+  };
+
+  ParseResult() = default;
+  ParseResult(const ParseResult&) = default;
+
+  ParseResult(NameHashMap&& keys, ParsedHashMap&& values, std::vector<KeyValue> sequential,
+          std::vector<KeyValue> default_opts, std::vector<std::string>&& unmatched_args)
+  : m_keys(std::move(keys))
+  , m_values(std::move(values))
+  , m_sequential(std::move(sequential))
+  , m_defaults(std::move(default_opts))
+  , m_unmatched(std::move(unmatched_args))
+  {
+  }
+
+  ParseResult& operator=(ParseResult&&) = default;
+  ParseResult& operator=(const ParseResult&) = default;
+
+  Iterator
+  begin() const
+  {
+    return Iterator(this);
+  }
+
+  Iterator
+  end() const
+  {
+    return Iterator(this, true);
+  }
+
+  std::size_t
+  count(const std::string& o) const
+  {
+    auto iter = m_keys.find(o);
+    if (iter == m_keys.end())
+    {
+      return 0;
+    }
+
+    auto viter = m_values.find(iter->second);
+
+    if (viter == m_values.end())
+    {
+      return 0;
+    }
+
+    return viter->second.count();
+  }
+
+  const OptionValue&
+  operator[](const std::string& option) const
+  {
+    auto iter = m_keys.find(option);
+
+    if (iter == m_keys.end())
+    {
+      throw_or_mimic<exceptions::requested_option_not_present>(option);
+    }
+
+    auto viter = m_values.find(iter->second);
+
+    if (viter == m_values.end())
+    {
+      throw_or_mimic<exceptions::requested_option_not_present>(option);
+    }
+
+    return viter->second;
+  }
+
+  const std::vector<KeyValue>&
+  arguments() const
+  {
+    return m_sequential;
+  }
+
+  const std::vector<std::string>&
+  unmatched() const
+  {
+    return m_unmatched;
+  }
+
+  const std::vector<KeyValue>&
+  defaults() const
+  {
+    return m_defaults;
+  }
+
+  const std::string
+  arguments_string() const
+  {
+    std::string result;
+    for(const auto& kv: m_sequential)
+    {
+      result += kv.key() + " = " + kv.value() + "\n";
+    }
+    for(const auto& kv: m_defaults)
+    {
+      result += kv.key() + " = " + kv.value() + " " + "(default)" + "\n";
+    }
+    return result;
+  }
+
+  private:
+  NameHashMap m_keys{};
+  ParsedHashMap m_values{};
+  std::vector<KeyValue> m_sequential{};
+  std::vector<KeyValue> m_defaults{};
+  std::vector<std::string> m_unmatched{};
+};
+
+struct Option
+{
+  Option
+  (
+    std::string opts,
+    std::string desc,
+    std::shared_ptr<const Value>  value = ::cxxopts::value<bool>(),
+    std::string arg_help = ""
+  )
+  : opts_(std::move(opts))
+  , desc_(std::move(desc))
+  , value_(std::move(value))
+  , arg_help_(std::move(arg_help))
+  {
+  }
+
+  std::string opts_;
+  std::string desc_;
+  std::shared_ptr<const Value> value_;
+  std::string arg_help_;
+};
+
+using OptionMap = std::unordered_map<std::string, std::shared_ptr<OptionDetails>>;
+using PositionalList = std::vector<std::string>;
+using PositionalListIterator = PositionalList::const_iterator;
+
+class OptionParser
+{
+  public:
+  OptionParser(const OptionMap& options, const PositionalList& positional, bool allow_unrecognised)
+  : m_options(options)
+  , m_positional(positional)
+  , m_allow_unrecognised(allow_unrecognised)
+  {
+  }
+
+  ParseResult
+  parse(int argc, const char* const* argv);
+
+  bool
+  consume_positional(const std::string& a, PositionalListIterator& next);
+
+  void
+  checked_parse_arg
+  (
+    int argc,
+    const char* const* argv,
+    int& current,
+    const std::shared_ptr<OptionDetails>& value,
+    const std::string& name
+  );
+
+  void
+  add_to_option(OptionMap::const_iterator iter, const std::string& option, const std::string& arg);
+
+  void
+  parse_option
+  (
+    const std::shared_ptr<OptionDetails>& value,
+    const std::string& name,
+    const std::string& arg = ""
+  );
+
+  void
+  parse_default(const std::shared_ptr<OptionDetails>& details);
+
+  void
+  parse_no_value(const std::shared_ptr<OptionDetails>& details);
+
+  private:
+
+  void finalise_aliases();
+
+  const OptionMap& m_options;
+  const PositionalList& m_positional;
+
+  std::vector<KeyValue> m_sequential{};
+  std::vector<KeyValue> m_defaults{};
+  bool m_allow_unrecognised;
+
+  ParsedHashMap m_parsed{};
+  NameHashMap m_keys{};
+};
+
+class Options
+{
+  public:
+
+  explicit Options(std::string program_name, std::string help_string = "")
+  : m_program(std::move(program_name))
+  , m_help_string(toLocalString(std::move(help_string)))
+  , m_custom_help("[OPTION...]")
+  , m_positional_help("positional parameters")
+  , m_show_positional(false)
+  , m_allow_unrecognised(false)
+  , m_width(76)
+  , m_tab_expansion(false)
+  , m_options(std::make_shared<OptionMap>())
+  {
+  }
+
+  Options&
+  positional_help(std::string help_text)
+  {
+    m_positional_help = std::move(help_text);
+    return *this;
+  }
+
+  Options&
+  custom_help(std::string help_text)
+  {
+    m_custom_help = std::move(help_text);
+    return *this;
+  }
+
+  Options&
+  show_positional_help()
+  {
+    m_show_positional = true;
+    return *this;
+  }
+
+  Options&
+  allow_unrecognised_options()
+  {
+    m_allow_unrecognised = true;
+    return *this;
+  }
+
+  Options&
+  set_width(std::size_t width)
+  {
+    m_width = width;
+    return *this;
+  }
+
+  Options&
+  set_tab_expansion(bool expansion=true)
+  {
+    m_tab_expansion = expansion;
+    return *this;
+  }
+
+  ParseResult
+  parse(int argc, const char* const* argv);
+
+  OptionAdder
+  add_options(std::string group = "");
+
+  void
+  add_options
+  (
+    const std::string& group,
+    std::initializer_list<Option> options
+  );
+
+  void
+  add_option
+  (
+    const std::string& group,
+    const Option& option
+  );
+
+  void
+  add_option
+  (
+    const std::string& group,
+    const std::string& s,
+    const OptionNames& l,
+    std::string desc,
+    const std::shared_ptr<const Value>& value,
+    std::string arg_help
+  );
+
+  void
+  add_option
+  (
+    const std::string& group,
+    const std::string& short_name,
+    const std::string& single_long_name,
+    std::string desc,
+    const std::shared_ptr<const Value>& value,
+    std::string arg_help
+  )
+  {
+    OptionNames long_names;
+    long_names.emplace_back(single_long_name);
+    add_option(group, short_name, long_names, desc, value, arg_help);
+  }
+
+  //parse positional arguments into the given option
+  void
+  parse_positional(std::string option);
+
+  void
+  parse_positional(std::vector<std::string> options);
+
+  void
+  parse_positional(std::initializer_list<std::string> options);
+
+  template <typename Iterator>
+  void
+  parse_positional(Iterator begin, Iterator end) {
+    parse_positional(std::vector<std::string>{begin, end});
+  }
+
+  std::string
+  help(const std::vector<std::string>& groups = {}, bool print_usage=true) const;
+
+  std::vector<std::string>
+  groups() const;
+
+  const HelpGroupDetails&
+  group_help(const std::string& group) const;
+
+  const std::string& program() const
+  {
+    return m_program;
+  }
+
+  private:
+
+  void
+  add_one_option
+  (
+    const std::string& option,
+    const std::shared_ptr<OptionDetails>& details
+  );
+
+  String
+  help_one_group(const std::string& group) const;
+
+  void
+  generate_group_help
+  (
+    String& result,
+    const std::vector<std::string>& groups
+  ) const;
+
+  void
+  generate_all_groups_help(String& result) const;
+
+  std::string m_program{};
+  String m_help_string{};
+  std::string m_custom_help{};
+  std::string m_positional_help{};
+  bool m_show_positional;
+  bool m_allow_unrecognised;
+  std::size_t m_width;
+  bool m_tab_expansion;
+
+  std::shared_ptr<OptionMap> m_options;
+  std::vector<std::string> m_positional{};
+  std::unordered_set<std::string> m_positional_set{};
+
+  //mapping from groups to help options
+  std::map<std::string, HelpGroupDetails> m_help{};
+};
+
+class OptionAdder
+{
+  public:
+
+  OptionAdder(Options& options, std::string group)
+  : m_options(options), m_group(std::move(group))
+  {
+  }
+
+  OptionAdder&
+  operator()
+  (
+    const std::string& opts,
+    const std::string& desc,
+    const std::shared_ptr<const Value>& value
+      = ::cxxopts::value<bool>(),
+    std::string arg_help = ""
+  );
+
+  private:
+  Options& m_options;
+  std::string m_group;
+};
+
+namespace {
+constexpr std::size_t OPTION_LONGEST = 30;
+constexpr std::size_t OPTION_DESC_GAP = 2;
+
+String
+format_option
+(
+  const HelpOptionDetails& o
+)
+{
+  const auto& s = o.s;
+  const auto& l = first_or_empty(o.l);
+
+  String result = "  ";
+
+  if (!s.empty())
+  {
+    result += "-" + toLocalString(s);
+    if (!l.empty())
+    {
+      result += ",";
+    }
+  }
+  else
+  {
+    result += "   ";
+  }
+
+  if (!l.empty())
+  {
+    result += " --" + toLocalString(l);
+  }
+
+  auto arg = !o.arg_help.empty() ? toLocalString(o.arg_help) : "arg";
+
+  if (!o.is_boolean)
+  {
+    if (o.has_implicit)
+    {
+      result += " [=" + arg + "(=" + toLocalString(o.implicit_value) + ")]";
+    }
+    else
+    {
+      result += " " + arg;
+    }
+  }
+
+  return result;
+}
+
+String
+format_description
+(
+  const HelpOptionDetails& o,
+  std::size_t start,
+  std::size_t allowed,
+  bool tab_expansion
+)
+{
+  auto desc = o.desc;
+
+  if (o.has_default && (!o.is_boolean || o.default_value != "false"))
+  {
+    if(!o.default_value.empty())
+    {
+      desc += toLocalString(" (default: " + o.default_value + ")");
+    }
+    else
+    {
+      desc += toLocalString(" (default: \"\")");
+    }
+  }
+
+  String result;
+
+  if (tab_expansion)
+  {
+    String desc2;
+    auto size = std::size_t{ 0 };
+    for (auto c = std::begin(desc); c != std::end(desc); ++c)
+    {
+      if (*c == '\n')
+      {
+        desc2 += *c;
+        size = 0;
+      }
+      else if (*c == '\t')
+      {
+        auto skip = 8 - size % 8;
+        stringAppend(desc2, skip, ' ');
+        size += skip;
+      }
+      else
+      {
+        desc2 += *c;
+        ++size;
+      }
+    }
+    desc = desc2;
+  }
+
+  desc += " ";
+
+  auto current = std::begin(desc);
+  auto previous = current;
+  auto startLine = current;
+  auto lastSpace = current;
+
+  auto size = std::size_t{};
+
+  bool appendNewLine;
+  bool onlyWhiteSpace = true;
+
+  while (current != std::end(desc))
+  {
+    appendNewLine = false;
+    if (*previous == ' ' || *previous == '\t')
+    {
+      lastSpace = current;
+    }
+    if (*current != ' ' && *current != '\t')
+    {
+      onlyWhiteSpace = false;
+    }
+
+    while (*current == '\n')
+    {
+      previous = current;
+      ++current;
+      appendNewLine = true;
+    }
+
+    if (!appendNewLine && size >= allowed)
+    {
+      if (lastSpace != startLine)
+      {
+        current = lastSpace;
+        previous = current;
+      }
+      appendNewLine = true;
+    }
+
+    if (appendNewLine)
+    {
+      stringAppend(result, startLine, current);
+      startLine = current;
+      lastSpace = current;
+
+      if (*previous != '\n')
+      {
+        stringAppend(result, "\n");
+      }
+
+      stringAppend(result, start, ' ');
+
+      if (*previous != '\n')
+      {
+        stringAppend(result, lastSpace, current);
+      }
+
+      onlyWhiteSpace = true;
+      size = 0;
+    }
+
+    previous = current;
+    ++current;
+    ++size;
+  }
+
+  //append whatever is left but ignore whitespace
+  if (!onlyWhiteSpace)
+  {
+    stringAppend(result, startLine, previous);
+  }
+
+  return result;
+}
+
+} // namespace
+
+inline
+void
+Options::add_options
+(
+  const std::string &group,
+  std::initializer_list<Option> options
+)
+{
+ OptionAdder option_adder(*this, group);
+ for (const auto &option: options)
+ {
+   option_adder(option.opts_, option.desc_, option.value_, option.arg_help_);
+ }
+}
+
+inline
+OptionAdder
+Options::add_options(std::string group)
+{
+  return OptionAdder(*this, std::move(group));
+}
+
+inline
+OptionAdder&
+OptionAdder::operator()
+(
+  const std::string& opts,
+  const std::string& desc,
+  const std::shared_ptr<const Value>& value,
+  std::string arg_help
+)
+{
+  OptionNames option_names = values::parser_tool::split_option_names(opts);
+    // Note: All names will be non-empty; but we must separate the short
+    // (length-1) and longer names
+  std::string short_name {""};
+  auto first_short_name_iter =
+    std::partition(option_names.begin(), option_names.end(),
+      [&](const std::string& name) { return name.length() > 1; }
+    );
+  auto num_length_1_names = (option_names.end() - first_short_name_iter);
+  switch(num_length_1_names) {
+  case 1:
+    short_name = *first_short_name_iter;
+    option_names.erase(first_short_name_iter);
+  case 0:
+    break;
+  default:
+    throw_or_mimic<exceptions::invalid_option_format>(opts);
+  };
+
+  m_options.add_option
+  (
+    m_group,
+    short_name,
+    option_names,
+    desc,
+    value,
+    std::move(arg_help)
+  );
+
+  return *this;
+}
+
+inline
+void
+OptionParser::parse_default(const std::shared_ptr<OptionDetails>& details)
+{
+  // TODO: remove the duplicate code here
+  auto& store = m_parsed[details->hash()];
+  store.parse_default(details);
+  m_defaults.emplace_back(details->essential_name(), details->value().get_default_value());
+}
+
+inline
+void
+OptionParser::parse_no_value(const std::shared_ptr<OptionDetails>& details)
+{
+  auto& store = m_parsed[details->hash()];
+  store.parse_no_value(details);
+}
+
+inline
+void
+OptionParser::parse_option
+(
+  const std::shared_ptr<OptionDetails>& value,
+  const std::string& /*name*/,
+  const std::string& arg
+)
+{
+  auto hash = value->hash();
+  auto& result = m_parsed[hash];
+  result.parse(value, arg);
+
+  m_sequential.emplace_back(value->essential_name(), arg);
+}
+
+inline
+void
+OptionParser::checked_parse_arg
+(
+  int argc,
+  const char* const* argv,
+  int& current,
+  const std::shared_ptr<OptionDetails>& value,
+  const std::string& name
+)
+{
+  if (current + 1 >= argc)
+  {
+    if (value->value().has_implicit())
+    {
+      parse_option(value, name, value->value().get_implicit_value());
+    }
+    else
+    {
+      throw_or_mimic<exceptions::missing_argument>(name);
+    }
+  }
+  else
+  {
+    if (value->value().has_implicit())
+    {
+      parse_option(value, name, value->value().get_implicit_value());
+    }
+    else
+    {
+      parse_option(value, name, argv[current + 1]);
+      ++current;
+    }
+  }
+}
+
+inline
+void
+OptionParser::add_to_option(OptionMap::const_iterator iter, const std::string& option, const std::string& arg)
+{
+  parse_option(iter->second, option, arg);
+}
+
+inline
+bool
+OptionParser::consume_positional(const std::string& a, PositionalListIterator& next)
+{
+  while (next != m_positional.end())
+  {
+    auto iter = m_options.find(*next);
+    if (iter != m_options.end())
+    {
+      if (!iter->second->value().is_container())
+      {
+        auto& result = m_parsed[iter->second->hash()];
+        if (result.count() == 0)
+        {
+          add_to_option(iter, *next, a);
+          ++next;
+          return true;
+        }
+        ++next;
+        continue;
+      }
+      add_to_option(iter, *next, a);
+      return true;
+    }
+    throw_or_mimic<exceptions::no_such_option>(*next);
+  }
+
+  return false;
+}
+
+inline
+void
+Options::parse_positional(std::string option)
+{
+  parse_positional(std::vector<std::string>{std::move(option)});
+}
+
+inline
+void
+Options::parse_positional(std::vector<std::string> options)
+{
+  m_positional = std::move(options);
+
+  m_positional_set.insert(m_positional.begin(), m_positional.end());
+}
+
+inline
+void
+Options::parse_positional(std::initializer_list<std::string> options)
+{
+  parse_positional(std::vector<std::string>(options));
+}
+
+inline
+ParseResult
+Options::parse(int argc, const char* const* argv)
+{
+  OptionParser parser(*m_options, m_positional, m_allow_unrecognised);
+
+  return parser.parse(argc, argv);
+}
+
+inline ParseResult
+OptionParser::parse(int argc, const char* const* argv)
+{
+  int current = 1;
+  bool consume_remaining = false;
+  auto next_positional = m_positional.begin();
+
+  std::vector<std::string> unmatched;
+
+  while (current != argc)
+  {
+    if (strcmp(argv[current], "--") == 0)
+    {
+      consume_remaining = true;
+      ++current;
+      break;
+    }
+    bool matched = false;
+    values::parser_tool::ArguDesc argu_desc =
+        values::parser_tool::ParseArgument(argv[current], matched);
+
+    if (!matched)
+    {
+      //not a flag
+
+      // but if it starts with a `-`, then it's an error
+      if (argv[current][0] == '-' && argv[current][1] != '\0') {
+        if (!m_allow_unrecognised) {
+          throw_or_mimic<exceptions::invalid_option_syntax>(argv[current]);
+        }
+      }
+
+      //if true is returned here then it was consumed, otherwise it is
+      //ignored
+      if (consume_positional(argv[current], next_positional))
+      {
+      }
+      else
+      {
+        unmatched.emplace_back(argv[current]);
+      }
+      //if we return from here then it was parsed successfully, so continue
+    }
+    else
+    {
+      //short or long option?
+      if (argu_desc.grouping)
+      {
+        const std::string& s = argu_desc.arg_name;
+
+        for (std::size_t i = 0; i != s.size(); ++i)
+        {
+          std::string name(1, s[i]);
+          auto iter = m_options.find(name);
+
+          if (iter == m_options.end())
+          {
+            if (m_allow_unrecognised)
+            {
+              unmatched.push_back(std::string("-") + s[i]);
+              continue;
+            }
+            //error
+            throw_or_mimic<exceptions::no_such_option>(name);
+          }
+
+          auto value = iter->second;
+
+          if (i + 1 == s.size())
+          {
+            //it must be the last argument
+            checked_parse_arg(argc, argv, current, value, name);
+          }
+          else if (value->value().has_implicit())
+          {
+            parse_option(value, name, value->value().get_implicit_value());
+          }
+          else if (i + 1 < s.size())
+          {
+            std::string arg_value = s.substr(i + 1);
+            parse_option(value, name, arg_value);
+            break;
+          }
+          else
+          {
+            //error
+            throw_or_mimic<exceptions::option_requires_argument>(name);
+          }
+        }
+      }
+      else if (argu_desc.arg_name.length() != 0)
+      {
+        const std::string& name = argu_desc.arg_name;
+
+        auto iter = m_options.find(name);
+
+        if (iter == m_options.end())
+        {
+          if (m_allow_unrecognised)
+          {
+            // keep unrecognised options in argument list, skip to next argument
+            unmatched.emplace_back(argv[current]);
+            ++current;
+            continue;
+          }
+          //error
+          throw_or_mimic<exceptions::no_such_option>(name);
+        }
+
+        auto opt = iter->second;
+
+        //equals provided for long option?
+        if (argu_desc.set_value)
+        {
+          //parse the option given
+
+          parse_option(opt, name, argu_desc.value);
+        }
+        else
+        {
+          //parse the next argument
+          checked_parse_arg(argc, argv, current, opt, name);
+        }
+      }
+
+    }
+
+    ++current;
+  }
+
+  for (auto& opt : m_options)
+  {
+    auto& detail = opt.second;
+    const auto& value = detail->value();
+
+    auto& store = m_parsed[detail->hash()];
+
+    if (value.has_default()) {
+      if (!store.count() && !store.has_default()) {
+        parse_default(detail);
+      }
+    }
+    else {
+      parse_no_value(detail);
+    }
+  }
+
+  if (consume_remaining)
+  {
+    while (current < argc)
+    {
+      if (!consume_positional(argv[current], next_positional)) {
+        break;
+      }
+      ++current;
+    }
+
+    //adjust argv for any that couldn't be swallowed
+    while (current != argc) {
+      unmatched.emplace_back(argv[current]);
+      ++current;
+    }
+  }
+
+  finalise_aliases();
+
+  ParseResult parsed(std::move(m_keys), std::move(m_parsed), std::move(m_sequential), std::move(m_defaults), std::move(unmatched));
+  return parsed;
+}
+
+inline
+void
+OptionParser::finalise_aliases()
+{
+  for (auto& option: m_options)
+  {
+    auto& detail = *option.second;
+    auto hash = detail.hash();
+    m_keys[detail.short_name()] = hash;
+    for(const auto& long_name : detail.long_names()) {
+      m_keys[long_name] = hash;
+    }
+
+    m_parsed.emplace(hash, OptionValue());
+  }
+}
+
+inline
+void
+Options::add_option
+(
+  const std::string& group,
+  const Option& option
+)
+{
+    add_options(group, {option});
+}
+
+inline
+void
+Options::add_option
+(
+  const std::string& group,
+  const std::string& s,
+  const OptionNames& l,
+  std::string desc,
+  const std::shared_ptr<const Value>& value,
+  std::string arg_help
+)
+{
+  auto stringDesc = toLocalString(std::move(desc));
+  auto option = std::make_shared<OptionDetails>(s, l, stringDesc, value);
+
+  if (!s.empty())
+  {
+    add_one_option(s, option);
+  }
+
+  for(const auto& long_name : l) {
+    add_one_option(long_name, option);
+  }
+
+  //add the help details
+  auto& options = m_help[group];
+
+  options.options.emplace_back(HelpOptionDetails{s, l, stringDesc,
+      value->has_default(), value->get_default_value(),
+      value->has_implicit(), value->get_implicit_value(),
+      std::move(arg_help),
+      value->is_container(),
+      value->is_boolean()});
+}
+
+inline
+void
+Options::add_one_option
+(
+  const std::string& option,
+  const std::shared_ptr<OptionDetails>& details
+)
+{
+  auto in = m_options->emplace(option, details);
+
+  if (!in.second)
+  {
+    throw_or_mimic<exceptions::option_already_exists>(option);
+  }
+}
+
+inline
+String
+Options::help_one_group(const std::string& g) const
+{
+  using OptionHelp = std::vector<std::pair<String, String>>;
+
+  auto group = m_help.find(g);
+  if (group == m_help.end())
+  {
+    return "";
+  }
+
+  OptionHelp format;
+
+  std::size_t longest = 0;
+
+  String result;
+
+  if (!g.empty())
+  {
+    result += toLocalString(" " + g + " options:\n");
+  }
+
+  for (const auto& o : group->second.options)
+  {
+    if (o.l.size() &&
+        m_positional_set.find(o.l.front()) != m_positional_set.end() &&
+        !m_show_positional)
+    {
+      continue;
+    }
+
+    auto s = format_option(o);
+    longest = (std::max)(longest, stringLength(s));
+    format.push_back(std::make_pair(s, String()));
+  }
+  longest = (std::min)(longest, OPTION_LONGEST);
+
+  //widest allowed description -- min 10 chars for helptext/line
+  std::size_t allowed = 10;
+  if (m_width > allowed + longest + OPTION_DESC_GAP)
+  {
+    allowed = m_width - longest - OPTION_DESC_GAP;
+  }
+
+  auto fiter = format.begin();
+  for (const auto& o : group->second.options)
+  {
+    if (o.l.size() &&
+        m_positional_set.find(o.l.front()) != m_positional_set.end() &&
+        !m_show_positional)
+    {
+      continue;
+    }
+
+    auto d = format_description(o, longest + OPTION_DESC_GAP, allowed, m_tab_expansion);
+
+    result += fiter->first;
+    if (stringLength(fiter->first) > longest)
+    {
+      result += '\n';
+      result += toLocalString(std::string(longest + OPTION_DESC_GAP, ' '));
+    }
+    else
+    {
+      result += toLocalString(std::string(longest + OPTION_DESC_GAP -
+        stringLength(fiter->first),
+        ' '));
+    }
+    result += d;
+    result += '\n';
+
+    ++fiter;
+  }
+
+  return result;
+}
+
+inline
+void
+Options::generate_group_help
+(
+  String& result,
+  const std::vector<std::string>& print_groups
+) const
+{
+  for (std::size_t i = 0; i != print_groups.size(); ++i)
+  {
+    const String& group_help_text = help_one_group(print_groups[i]);
+    if (empty(group_help_text))
+    {
+      continue;
+    }
+    result += group_help_text;
+    if (i < print_groups.size() - 1)
+    {
+      result += '\n';
+    }
+  }
+}
+
+inline
+void
+Options::generate_all_groups_help(String& result) const
+{
+  std::vector<std::string> all_groups;
+
+  std::transform(
+    m_help.begin(),
+    m_help.end(),
+    std::back_inserter(all_groups),
+    [] (const std::map<std::string, HelpGroupDetails>::value_type& group)
+    {
+      return group.first;
+    }
+  );
+
+  generate_group_help(result, all_groups);
+}
+
+inline
+std::string
+Options::help(const std::vector<std::string>& help_groups, bool print_usage) const
+{
+  String result = m_help_string;
+  if(print_usage)
+  {
+    result+= "\nUsage:\n  " + toLocalString(m_program);
+  }
+
+  if (!m_custom_help.empty())
+  {
+    result += " " + toLocalString(m_custom_help);
+  }
+
+  if (!m_positional.empty() && !m_positional_help.empty()) {
+    result += " " + toLocalString(m_positional_help);
+  }
+
+  result += "\n\n";
+
+  if (help_groups.empty())
+  {
+    generate_all_groups_help(result);
+  }
+  else
+  {
+    generate_group_help(result, help_groups);
+  }
+
+  return toUTF8String(result);
+}
+
+inline
+std::vector<std::string>
+Options::groups() const
+{
+  std::vector<std::string> g;
+
+  std::transform(
+    m_help.begin(),
+    m_help.end(),
+    std::back_inserter(g),
+    [] (const std::map<std::string, HelpGroupDetails>::value_type& pair)
+    {
+      return pair.first;
+    }
+  );
+
+  return g;
+}
+
+inline
+const HelpGroupDetails&
+Options::group_help(const std::string& group) const
+{
+  return m_help.at(group);
+}
+
+} // namespace cxxopts
+
+#endif //CXXOPTS_HPP_INCLUDED
\ No newline at end of file
diff --git a/tensorflow/recom/utils.cc b/tensorflow/recom/utils.cc
new file mode 100644
index 00000000000..91490b5ce9b
--- /dev/null
+++ b/tensorflow/recom/utils.cc
@@ -0,0 +1,233 @@
+// Copyright 2023 The RECom Authors. All rights reserved.
+// 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.
+
+#include <cstdlib>
+#include <queue>
+#include <random>
+#include <string>
+#include <unordered_map>
+#include <vector>
+
+#include "absl/strings/str_replace.h"
+#include "tensorflow/c/c_api.h"
+#include "tensorflow/cc/saved_model/loader.h"
+#include "tensorflow/cc/saved_model/signature_constants.h"
+#include "tensorflow/core/framework/graph.pb.h"
+#include "tensorflow/core/framework/types.pb.h"
+#include "utils.h"
+
+namespace tensorflow {
+namespace benchmark {
+
+int GenRandomCol() { return rand() % 10 + 1; }
+
+int GenRandomInt() { return rand() % 100; }
+
+double GenRandomFP() {
+  return static_cast<double>(rand()) / static_cast<double>(RAND_MAX) * 100;
+}
+
+std::string GenRandomStr() {
+  std::string raw = std::to_string(GenRandomFP());
+  return raw.substr(0, raw.find(".") + 5);
+}
+
+std::string GenRandonStrWithDelim(const std::string& delim) {
+  std::vector<std::string> elements(GenRandomCol());
+  std::generate(elements.begin(), elements.end(), GenRandomStr);
+  return absl::StrJoin(elements, delim);
+}
+
+std::string GenRandonStrWithDelim(const std::string& delim, int ncols) {
+  std::vector<std::string> elements(ncols);
+  std::generate(elements.begin(), elements.end(), GenRandomStr);
+  return absl::StrJoin(elements, delim);
+}
+
+std::string ExtractNodeByTensor(const std::string& tname) {
+  std::string replaced = absl::StrReplaceAll(tname, {{"^", ""}});
+  std::vector<std::string> splitted = absl::StrSplit(replaced, ":");
+  return splitted.size() > 0 ? splitted[0] : "";
+}
+
+void ConstructGraphInputs(const GraphDef& gd, int batch_size,
+                          std::vector<std::pair<std::string, Tensor>>& inputs) {
+  std::unordered_map<std::string, const NodeDef*> node_mapping;
+  for (const NodeDef& node : gd.node()) {
+    node_mapping[node.name()] = &node;
+  }
+
+  std::vector<int> batch_ncols(batch_size);
+  std::generate(batch_ncols.begin(), batch_ncols.end(), GenRandomCol);
+
+  std::unordered_map<std::string, Tensor> input_dict;
+  for (const NodeDef& node : gd.node()) {
+    if (node.op() == "StringSplitV2" || node.op() == "StringSplit") {
+      const NodeDef* delim_node =
+          node_mapping.at(ExtractNodeByTensor(node.input(1)));
+      std::string delim = delim_node->attr().at("value").tensor().string_val(0);
+      // LOG(INFO) << "StringSplit Node: " << delim_node->name()
+      //           << ", Delimeter: " << delim;
+
+      std::queue<const NodeDef*> node_queue;
+      node_queue.push(node_mapping.at(ExtractNodeByTensor(node.input(0))));
+      while (!node_queue.empty()) {
+        const NodeDef* n = node_queue.front();
+        node_queue.pop();
+
+        if (n->op() == "Placeholder") {
+          Tensor t(DT_STRING, {batch_size});
+          for (int i = 0; i < batch_size; ++i) {
+            t.flat<tstring>()(i) = GenRandonStrWithDelim(delim, batch_ncols[i]);
+          }
+          input_dict[n->name() + ":0"] = t;
+        }
+
+        for (const std::string& p : n->input()) {
+          node_queue.push(node_mapping.at(ExtractNodeByTensor(p)));
+        }
+      }
+    }
+  }
+
+  for (const NodeDef& node : gd.node()) {
+    if (node.op() == "Placeholder" && !input_dict.count(node.name() + ":0")) {
+      const auto& shape_ptoto = node.attr().at("shape").shape();
+      TensorShape shape;
+      for (int i = 0; i < shape_ptoto.dim_size(); ++i) {
+        if (shape_ptoto.dim(i).size() < 0) {
+          shape.AddDim(batch_size);
+        } else {
+          shape.AddDim(shape_ptoto.dim(i).size());
+        }
+      }
+      DataType dtype = node.attr().at("dtype").type();
+      Tensor t(dtype, shape);
+      switch (dtype) {
+        case DT_FLOAT: {
+          for (int i = 0; i < t.NumElements(); ++i) {
+            t.flat<float>()(i) = GenRandomFP();
+          }
+        } break;
+        case DT_DOUBLE: {
+          for (int i = 0; i < t.NumElements(); ++i) {
+            t.flat<double>()(i) = GenRandomFP();
+          }
+        } break;
+        case DT_INT32: {
+          for (int i = 0; i < t.NumElements(); ++i) {
+            t.flat<int>()(i) = GenRandomInt();
+          }
+        } break;
+        case DT_INT64: {
+          for (int i = 0; i < t.NumElements(); ++i) {
+            t.flat<int64>()(i) = GenRandomInt();
+          }
+        } break;
+        case DT_STRING: {
+          for (int i = 0; i < t.NumElements(); ++i) {
+            t.flat<tstring>()(i) = GenRandomStr();
+          }
+        } break;
+        default:
+          LOG(ERROR) << "Not support the input type " << DataTypeString(dtype);
+          exit(-1);
+      }
+      input_dict[node.name() + ":0"] = t;
+    }
+  }
+
+  inputs = std::vector<std::pair<std::string, Tensor>>(input_dict.begin(),
+                                                       input_dict.end());
+}
+
+void LoadSavedModelWrap(const std::string& model_path, int intra_threads,
+                        int inter_threads,
+                        std::shared_ptr<SavedModelBundle>& bundle,
+                        bool use_gpu) {
+  std::unordered_set<std::string> tags = {"serve"};
+  bundle.reset(new SavedModelBundle());
+  auto options = SessionOptions();
+  options.config.set_intra_op_parallelism_threads(intra_threads);
+  options.config.set_inter_op_parallelism_threads(inter_threads);
+  if (!use_gpu) (*options.config.mutable_device_count())["GPU"] = 0;
+  auto* gpu_opt = options.config.mutable_gpu_options();
+  gpu_opt->set_per_process_gpu_memory_fraction(0.7);
+  gpu_opt->set_allow_growth(true);
+
+  LOG(INFO) << "Start load model";
+  auto t1 = std::chrono::high_resolution_clock::now();
+  Status status =
+      LoadSavedModel(options, RunOptions(), model_path, tags, bundle.get());
+  if (!status.ok()) {
+    LOG(ERROR) << "Loading tf model failed. dir: " << model_path
+               << " status:" << status.ToString();
+    exit(-1);
+  }
+  auto t2 = std::chrono::high_resolution_clock::now();
+
+  int load_time =
+      std::chrono::duration_cast<std::chrono::seconds>(t2 - t1).count();
+  LOG(INFO) << "Load model time: " << load_time << "s";
+}
+
+void ExtractGraphOutputs(const std::shared_ptr<SavedModelBundle>& bundle,
+                         std::vector<std::string>& outputs) {
+  outputs = std::vector<std::string>();
+  for (auto signature_item : bundle->meta_graph_def.signature_def()) {
+    if (signature_item.first == kDefaultServingSignatureDefKey) {
+      SignatureDef signature = signature_item.second;
+      if (signature.method_name() != kPredictMethodName &&
+          signature.method_name() != kClassifyMethodName &&
+          signature.method_name() != kRegressMethodName) {
+        LOG(ERROR)
+            << "Expected prediction signature method_name must be one of {"
+            << kPredictMethodName << ", " << kClassifyMethodName << ", "
+            << kRegressMethodName << "}. Was: " << signature.method_name();
+      }
+
+      for (auto output : signature.outputs()) {
+        outputs.push_back(output.second.name());
+      }
+    }
+  }
+}
+
+void ExtractGraphConcats(const GraphDef& gd,
+                         std::vector<std::string>& outputs) {
+  // The concat extraction logic is very simple here as we know the number of
+  // embedding columns of each benchmark model is > 5, while other concat nodes
+  // other than the converging node only have < 5 inputs. Do NOT rely on it to
+  // extract converging node in production.
+  LOG(INFO) << "Please ensure the number of embedding columns is > 5";
+  outputs = std::vector<std::string>();
+  for (const NodeDef& node : gd.node()) {
+    if (node.op() == "ConcatV2" && node.input_size() > 5) {
+      outputs.push_back(node.name() + ":0");
+    }
+  }
+}
+
+void LoadOpLibrary(const std::string& lib_path) {
+  TF_Status* load_status = TF_NewStatus();
+  TF_Library* lib_handle = TF_LoadLibrary(lib_path.c_str(), load_status);
+  if (TF_GetCode(load_status) == TF_OK) {
+    LOG(INFO) << "Load " << lib_path << " successfully";
+  } else {
+    LOG(INFO) << "Failed to load " << lib_path << ": "
+              << TF_Message(load_status);
+  }
+  TF_DeleteStatus(load_status);
+  TF_DeleteLibraryHandle(lib_handle);
+}
+
+}  // namespace benchmark
+}  // namespace tensorflow
\ No newline at end of file
diff --git a/tensorflow/recom/utils.h b/tensorflow/recom/utils.h
new file mode 100644
index 00000000000..236570c3695
--- /dev/null
+++ b/tensorflow/recom/utils.h
@@ -0,0 +1,52 @@
+// Copyright 2023 The RECom Authors. All rights reserved.
+// 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.
+
+#pragma once
+#include <string>
+#include <vector>
+
+#include "tensorflow/cc/saved_model/loader.h"
+#include "tensorflow/core/framework/graph.pb.h"
+
+namespace tensorflow {
+namespace benchmark {
+
+int GenRandomCol();
+
+int GenRandomInt();
+
+double GenRandomFP();
+
+std::string GenRandomStr();
+
+std::string GenRandonStrWithDelim(const std::string& delim);
+
+std::string GenRandonStrWithDelim(const std::string& delim, int ncols);
+
+void LoadSavedModelWrap(const std::string& model_path, int intra_threads,
+                        int inter_threads,
+                        std::shared_ptr<SavedModelBundle>& bundle,
+                        bool use_gpu = true);
+
+void LoadOpLibrary(const std::string& lib_path);
+
+std::string ExtractNodeByTensor(const std::string& tname);
+
+void ConstructGraphInputs(const GraphDef& gd, int batch_size,
+                          std::vector<std::pair<std::string, Tensor>>& inputs);
+
+void ExtractGraphOutputs(const std::shared_ptr<SavedModelBundle>& bundle,
+                         std::vector<std::string>& outputs);
+
+void ExtractGraphConcats(const GraphDef& gd, std::vector<std::string>& outputs);
+
+}  // namespace benchmark
+}  // namespace tensorflow
\ No newline at end of file