Fixes jarro2783/cxxopts#338: Split the library into multiple header files - mostly one for each class.

CMakeLists.txt

@@ -56,7 +56,7 @@ if (CXXOPTS_ENABLE_WARNINGS)
     cxxopts_enable_warnings()
 endif()
 
-add_library(cxxopts INTERFACE)
+add_library(cxxopts INTERFACE include/cxxopts.hpp)
 add_library(cxxopts::cxxopts ALIAS cxxopts)
 add_subdirectory(include)
 

include/cxxopts/KeyValue.hpp

@@ -0,0 +1,51 @@
+#ifndef CXXOPTS_KEYVALUE_HPP_
+#define CXXOPTS_KEYVALUE_HPP_
+
+#include "common.hpp"
+#include "values.hpp"
+
+#include <string>
+#include <utility>
+
+namespace cxxopts {
+
+  class KeyValue
+  {
+  public:
+    KeyValue(std::string key_, std::string value_)
+    : 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;
+  };
+
+
+} // namespace cxxopts
+#endif //CXXOPTS_KEYVALUE_HPP_

include/cxxopts/Option.hpp

@@ -0,0 +1,41 @@
+#ifndef CXXOPTS_OPTION_HPP_
+#define CXXOPTS_OPTION_HPP_
+
+#include "common.hpp"
+#include "values.hpp"
+
+#include <memory>
+#include <utility>
+#include <string>
+
+namespace cxxopts
+{
+
+  class OptionDetails;
+
+  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_;
+  };
+
+
+} // namespace cxxopts
+
+#endif //CXXOPTS_OPTION_HPP_

include/cxxopts/OptionParser.hpp

@@ -0,0 +1,382 @@
+#ifndef CXXOPTS_OPTIONPARSER_HPP_
+#define CXXOPTS_OPTIONPARSER_HPP_
+
+#include "common.hpp"
+#include "KeyValue.hpp"
+#include "Option.hpp"
+#include "OptionValue.hpp"
+#include "ParseResult.hpp"
+
+#include <cstring>
+#include <algorithm>
+#include <cstddef>
+#include <memory>
+#include <string>
+#include <unordered_map>
+#include <utility>
+#include <vector>
+
+namespace cxxopts {
+
+  using NameHashMap = std::unordered_map<std::string, size_t>;
+
+  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);
+    // Implemented along with ParseResult
+
+    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{};
+  };
+
+  inline
+  void
+  OptionParser::finalise_aliases()
+  {
+    for (auto& option: m_options)
+    {
+      auto& detail = *option.second;
+      auto hash = detail.hash();
+      m_keys[detail.short_name()] = hash;
+      m_keys[detail.long_name()] = hash;
+
+      m_parsed.emplace(hash, OptionValue());
+    }
+  }
+
+  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->long_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->long_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<missing_argument_exception>(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<option_not_exists_exception>(*next);
+    }
+
+    return false;
+  }
+
+  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<option_syntax_exception>(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<option_not_exists_exception>(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<option_requires_argument_exception>(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<option_not_exists_exception>(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;
+  }
+
+} // namespace cxxopts
+
+#endif //CXXOPTS_OPTIONPARSER_HPP_

include/cxxopts/OptionValue.hpp

@@ -0,0 +1,217 @@
+#ifndef CXXOPTS_OPTIONVALUE_HPP_
+#define CXXOPTS_OPTIONVALUE_HPP_
+
+#include "common.hpp"
+#include "String.hpp"
+#include "exceptions.hpp"
+#include "values.hpp"
+
+#include <cstddef>
+#include <string>
+#include <memory>
+#include <unordered_map>
+#include <unordered_set>
+#include <utility>
+#include <vector>
+
+#if (__GNUC__ < 10 || (__GNUC__ == 10 && __GNUC_MINOR__ < 1)) && __GNUC__ >= 6
+#define CXXOPTS_NULL_DEREF_IGNORE
+#endif
+
+namespace cxxopts
+{
+  class OptionDetails
+  {
+  public:
+    OptionDetails
+    (
+    std::string short_,
+    std::string 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>{}(m_long + 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&
+    long_name() const
+    {
+      return m_long;
+    }
+
+    size_t
+    hash() const
+    {
+      return m_hash;
+    }
+
+  private:
+    std::string m_short{};
+    std::string m_long{};
+    String m_desc{};
+    std::shared_ptr<const Value> m_value{};
+    int m_count;
+
+    size_t m_hash{};
+  };
+
+  struct HelpOptionDetails
+  {
+    std::string s;
+    std::string 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_name = &details->long_name();
+    }
+
+    void
+    parse_default(const std::shared_ptr<const OptionDetails>& details)
+    {
+      ensure_value(details);
+      m_default = true;
+      m_long_name = &details->long_name();
+      m_value->parse();
+    }
+
+    void
+    parse_no_value(const std::shared_ptr<const OptionDetails>& details)
+    {
+      m_long_name = &details->long_name();
+    }
+
+#if defined(CXXOPTS_NULL_DEREF_IGNORE)
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Wnull-dereference"
+#endif
+
+    CXXOPTS_NODISCARD
+    size_t
+    count() const noexcept
+    {
+      return m_count;
+    }
+
+#if defined(CXXOPTS_NULL_DEREF_IGNORE)
+#pragma GCC 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<option_has_no_value_exception>(
+              m_long_name == nullptr ? "" : *m_long_name);
+      }
+
+#ifdef CXXOPTS_NO_RTTI
+      return static_cast<const values::standard_value<T>&>(*m_value).get();
+#else
+      return dynamic_cast<const values::standard_value<T>&>(*m_value).get();
+#endif
+    }
+
+    private:
+    void
+    ensure_value(const std::shared_ptr<const OptionDetails>& details)
+    {
+      if (m_value == nullptr)
+      {
+        m_value = details->make_storage();
+      }
+    }
+
+
+    const std::string* m_long_name = 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{};
+    size_t m_count = 0;
+    bool m_default = false;
+  };
+
+  using ParsedHashMap = std::unordered_map<size_t, OptionValue>;
+  using NameHashMap = std::unordered_map<std::string, size_t>;
+
+} // namespace cxxopts
+
+#endif //CXXOPTS_OPTIONVALUE_HPP_

include/cxxopts/Options.hpp

@@ -0,0 +1,735 @@
+#ifndef CXXOPTS_OPTIONS_HPP_
+#define CXXOPTS_OPTIONS_HPP_
+
+#include "common.hpp"
+#include "exceptions.hpp"
+#include "values.hpp"
+#include "Option.hpp"
+#include "OptionParser.hpp"
+#include "ParseResult.hpp"
+
+#include <memory>
+#include <unordered_map>
+#include <unordered_set>
+#include <utility>
+#include <vector>
+#include <cctype>
+#include <cstddef>
+#include <algorithm>
+#include <initializer_list>
+#include <iterator>
+#include <map>
+#include <string>
+#include <tuple>
+#include <type_traits>
+
+
+namespace cxxopts
+{
+  class Options;
+
+  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;
+  };
+
+
+  class Options
+  {
+    public:
+
+    explicit Options(std::string program, std::string help_string = "")
+    : m_program(std::move(program))
+    , 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(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 std::string& l,
+      std::string desc,
+      const std::shared_ptr<const Value>& value,
+      std::string 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 = {}) 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;
+    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{};
+  };
+
+  namespace
+  {
+    constexpr size_t OPTION_LONGEST = 30;
+    constexpr size_t OPTION_DESC_GAP = 2;
+
+    String
+    format_option
+    (
+      const HelpOptionDetails& o
+    )
+    {
+      const auto& s = o.s;
+      const auto& l = 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,
+      size_t start,
+      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 = 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 = size_t{};
+
+      bool appendNewLine;
+      bool onlyWhiteSpace = true;
+
+      while (current != std::end(desc))
+      {
+        appendNewLine = false;
+
+        if (std::isblank(*previous))
+        {
+          lastSpace = current;
+        }
+
+        if (!std::isblank(*current))
+        {
+          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
+      )
+  {
+      std::string short_sw, long_sw;
+      std::tie(short_sw, long_sw) = values::parser_tool::SplitSwitchDef(opts);
+
+      if (!short_sw.length() && !long_sw.length())
+      {
+          throw_or_mimic<invalid_option_format_error>(opts);
+      }
+      else if (long_sw.length() == 1 && short_sw.length())
+      {
+          throw_or_mimic<invalid_option_format_error>(opts);
+      }
+
+      auto option_names = []
+          (
+              const std::string &short_,
+              const std::string &long_
+          )
+      {
+          if (long_.length() == 1)
+          {
+              return std::make_tuple(long_, short_);
+          }
+          return std::make_tuple(short_, long_);
+      }(short_sw, long_sw);
+
+      m_options.add_option
+          (
+              m_group,
+              std::get<0>(option_names),
+              std::get<1>(option_names),
+              desc,
+              value,
+              std::move(arg_help)
+          );
+
+      return *this;
+  }
+
+
+  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
+  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 std::string& 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);
+      }
+
+      if (!l.empty())
+      {
+          add_one_option(l, 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<option_exists_error>(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;
+
+      size_t longest = 0;
+
+      String result;
+
+      if (!g.empty())
+      {
+          result += toLocalString(" " + g + " options:\n");
+      }
+
+      for (const auto& o : group->second.options)
+      {
+          if (m_positional_set.find(o.l) != 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
+      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 (m_positional_set.find(o.l) != 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 (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) const
+  {
+      String result = m_help_string + "\nUsage:\n  " +
+                      toLocalString(m_program) + " " + 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_OPTIONS_HPP_

include/cxxopts/ParseResult.hpp

@@ -0,0 +1,189 @@
+#ifndef CXXOPTS_PARSERESULT_HPP_
+#define CXXOPTS_PARSERESULT_HPP_
+
+#include "KeyValue.hpp"
+#include "Option.hpp"
+#include "OptionValue.hpp"
+
+#include <cstddef>
+#include <iterator>
+#include <string>
+#include <unordered_map>
+#include <utility>
+#include <vector>
+
+namespace cxxopts {
+
+  using ParsedHashMap = std::unordered_map<size_t, OptionValue>;
+  using NameHashMap = std::unordered_map<std::string, 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;
+
+      Iterator(const ParseResult *pr, bool end = false)
+      : m_pr(pr), m_iter(end ? pr->m_defaults.end() : pr->m_sequential.begin())
+      {
+      }
+
+      Iterator &operator++()
+      {
+        ++m_iter;
+        if (m_iter == m_pr->m_sequential.end()) {
+          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_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;
+    };
+
+    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);
+    }
+
+    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<option_not_present_exception>(option);
+      }
+
+      auto viter = m_values.find(iter->second);
+
+      if (viter == m_values.end()) {
+        throw_or_mimic<option_not_present_exception>(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{};
+  };
+
+} // namespace cxxopts
+
+#endif //CXXOPTS_PARSERESULT_HPP_

include/cxxopts/String.hpp

@@ -0,0 +1,223 @@
+#ifndef CXXOPTS_STRING_HPP_
+#define CXXOPTS_STRING_HPP_
+
+#include "common.hpp"
+
+#include <cstring>
+#include <string>
+#include <utility>
+
+
+//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));
+  }
+
+#if defined(__GNUC__)
+// 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
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Wnon-virtual-dtor"
+#pragma GCC diagnostic ignored "-Weffc++"
+// This will be ignored under other compilers like LLVM clang.
+#endif
+  class UnicodeStringIterator : public
+    std::iterator<std::forward_iterator_tag, int32_t>
+  {
+    public:
+
+    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;
+  };
+#if defined(__GNUC__)
+#pragma GCC diagnostic pop
+#endif
+
+  inline
+  String&
+  stringAppend(String&s, String a)
+  {
+    return s.append(std::move(a));
+  }
+
+  inline
+  String&
+  stringAppend(String& s, size_t n, UChar32 c)
+  {
+    for (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 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 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());
+  }
+}
+
+//ifdef CXXOPTS_USE_UNICODE
+#else
+
+namespace cxxopts
+{
+  using String = std::string;
+
+  template <typename T>
+  T
+  toLocalString(T&& t)
+  {
+    return std::forward<T>(t);
+  }
+
+  inline
+  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, 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
+
+#endif //CXXOPTS_STRING_HPP_

include/cxxopts/common.hpp

@@ -0,0 +1,28 @@
+#ifndef CXXOPTS_COMMON_HPP_
+#define CXXOPTS_COMMON_HPP_
+
+#include <cstdint>
+
+#if __cplusplus >= 201603L
+#define CXXOPTS_NODISCARD [[nodiscard]]
+#else
+#define CXXOPTS_NODISCARD
+#endif
+
+#define CXXOPTS__VERSION_MAJOR 3
+#define CXXOPTS__VERSION_MINOR 0
+#define CXXOPTS__VERSION_PATCH 0
+
+namespace cxxopts
+{
+  static constexpr struct {
+    uint8_t major, minor, patch;
+  } version = {
+    CXXOPTS__VERSION_MAJOR,
+    CXXOPTS__VERSION_MINOR,
+    CXXOPTS__VERSION_PATCH
+  };
+} // namespace cxxopts
+
+
+#endif //CXXOPTS_COMMON_HPP_

include/cxxopts/exceptions.hpp

@@ -0,0 +1,204 @@
+#ifndef CXXOPTS_EXCEPTIONS_HPP_
+#define CXXOPTS_EXCEPTIONS_HPP_
+
+#include "common.hpp"
+
+#include <exception>
+#include <string>            // for operator+, allocator, string, char_traits
+#include <type_traits>       // for is_base_of
+#include <utility>           // for move
+
+namespace cxxopts
+{
+  namespace
+  {
+#ifdef _WIN32
+    const std::string LQUOTE("\'");
+    const std::string RQUOTE("\'");
+#else
+    const std::string LQUOTE("‘");
+    const std::string RQUOTE("’");
+#endif
+  } // namespace
+
+
+  class OptionException : public std::exception
+  {
+    public:
+    explicit OptionException(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 OptionSpecException : public OptionException
+  {
+    public:
+
+    explicit OptionSpecException(const std::string& message)
+    : OptionException(message)
+    {
+    }
+  };
+
+  class OptionParseException : public OptionException
+  {
+    public:
+    explicit OptionParseException(const std::string& message)
+    : OptionException(message)
+    {
+    }
+  };
+
+  class option_exists_error : public OptionSpecException
+  {
+    public:
+    explicit option_exists_error(const std::string& option)
+    : OptionSpecException("Option " + LQUOTE + option + RQUOTE + " already exists")
+    {
+    }
+  };
+
+  class invalid_option_format_error : public OptionSpecException
+  {
+    public:
+    explicit invalid_option_format_error(const std::string& format)
+    : OptionSpecException("Invalid option format " + LQUOTE + format + RQUOTE)
+    {
+    }
+  };
+
+  class option_syntax_exception : public OptionParseException {
+    public:
+    explicit option_syntax_exception(const std::string& text)
+    : OptionParseException("Argument " + LQUOTE + text + RQUOTE +
+        " starts with a - but has incorrect syntax")
+    {
+    }
+  };
+
+  class option_not_exists_exception : public OptionParseException
+  {
+    public:
+    explicit option_not_exists_exception(const std::string& option)
+    : OptionParseException("Option " + LQUOTE + option + RQUOTE + " does not exist")
+    {
+    }
+  };
+
+  class missing_argument_exception : public OptionParseException
+  {
+    public:
+    explicit missing_argument_exception(const std::string& option)
+    : OptionParseException(
+        "Option " + LQUOTE + option + RQUOTE + " is missing an argument"
+      )
+    {
+    }
+  };
+
+  class option_requires_argument_exception : public OptionParseException
+  {
+    public:
+    explicit option_requires_argument_exception(const std::string& option)
+    : OptionParseException(
+        "Option " + LQUOTE + option + RQUOTE + " requires an argument"
+      )
+    {
+    }
+  };
+
+  class option_not_has_argument_exception : public OptionParseException
+  {
+    public:
+    option_not_has_argument_exception
+    (
+      const std::string& option,
+      const std::string& arg
+    )
+    : OptionParseException(
+        "Option " + LQUOTE + option + RQUOTE +
+        " does not take an argument, but argument " +
+        LQUOTE + arg + RQUOTE + " given"
+      )
+    {
+    }
+  };
+
+  class option_not_present_exception : public OptionParseException
+  {
+    public:
+    explicit option_not_present_exception(const std::string& option)
+    : OptionParseException("Option " + LQUOTE + option + RQUOTE + " not present")
+    {
+    }
+  };
+
+  class option_has_no_value_exception : public OptionException
+  {
+    public:
+    explicit option_has_no_value_exception(const std::string& option)
+    : OptionException(
+        !option.empty() ?
+        ("Option " + LQUOTE + option + RQUOTE + " has no value") :
+        "Option has no value")
+    {
+    }
+  };
+
+  class argument_incorrect_type : public OptionParseException
+  {
+    public:
+    explicit argument_incorrect_type
+    (
+      const std::string& arg
+    )
+    : OptionParseException(
+        "Argument " + LQUOTE + arg + RQUOTE + " failed to parse"
+      )
+    {
+    }
+  };
+
+  class option_required_exception : public OptionParseException
+  {
+    public:
+    explicit option_required_exception(const std::string& option)
+    : OptionParseException(
+        "Option " + LQUOTE + option + RQUOTE + " is required but not present"
+      )
+    {
+    }
+  };
+
+  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
+  }
+} // namespace cxxopts
+
+#endif //CXXOPTS_EXCEPTIONS_HPP_

include/cxxopts/values.hpp

@@ -0,0 +1,776 @@
+#ifndef CXXOPTS_VALUES_HPP_
+#define CXXOPTS_VALUES_HPP_
+
+#include "common.hpp"
+#include "exceptions.hpp"
+
+#include <cstdint>
+#include <map>
+#include <limits>
+#include <type_traits>
+#include <memory>
+#include <sstream>
+#include <string>
+#include <utility>
+#include <vector>
+
+#if defined(__GNUC__) && !defined(__clang__)
+#  if (__GNUC__ * 10 + __GNUC_MINOR__) < 49
+#    define CXXOPTS_NO_REGEX true
+#  endif
+#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
+
+#ifndef CXXOPTS_VECTOR_DELIMITER
+#define CXXOPTS_VECTOR_DELIMITER ','
+#endif
+
+namespace cxxopts
+{
+#if defined(__GNUC__)
+// 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
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Wnon-virtual-dtor"
+#pragma GCC diagnostic ignored "-Weffc++"
+// This will be ignored under other compilers like LLVM clang.
+#endif
+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;
+};
+#if defined(__GNUC__)
+#pragma GCC diagnostic pop
+#endif
+
+  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<argument_incorrect_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<argument_incorrect_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 std::pair<std::string, std::string> SplitSwitchDef(const std::string &text)
+      {
+        std::string short_sw, long_sw;
+        const char *pdata = text.c_str();
+        if (isalnum(*pdata) && *(pdata + 1) == ',') {
+          short_sw = std::string(1, *pdata);
+          pdata += 2;
+        }
+        while (*pdata == ' ') { pdata += 1; }
+        if (isalnum(*pdata)) {
+          const char *store = pdata;
+          pdata += 1;
+          while (isalnum(*pdata) || *pdata == '-' || *pdata == '_') {
+            pdata += 1;
+          }
+          if (*pdata == '\0') {
+            long_sw = std::string(store, pdata - store);
+          } else {
+            throw_or_mimic<invalid_option_format_error>(text);
+          }
+        }
+        return std::pair<std::string, std::string>(short_sw, long_sw);
+      }
+
+      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))
+          {
+            argu_desc.arg_name.push_back(*pdata);
+            pdata += 1;
+            while (isalnum(*pdata) || *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))
+          {
+            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
+      {
+
+        std::basic_regex<char> integer_pattern
+          ("(-)?(0x)?([0-9a-zA-Z]+)|((0x)?0)");
+        std::basic_regex<char> truthy_pattern
+          ("(t|T)(rue)?|1");
+        std::basic_regex<char> falsy_pattern
+          ("(f|F)(alse)?|0");
+
+        std::basic_regex<char> option_matcher
+          ("--([[:alnum:]][-_[:alnum:]]+)(=(.*))?|-([[:alnum:]]+)");
+        std::basic_regex<char> option_specifier
+          ("(([[:alnum:]]),)?[ ]*([[:alnum:]][-_[:alnum:]]*)?");
+
+      } // 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<argument_incorrect_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();
+      }
+
+      inline std::pair<std::string, std::string> SplitSwitchDef(const std::string &text)
+      {
+        std::match_results<const char*> result;
+        std::regex_match(text.c_str(), result, option_specifier);
+        if (result.empty())
+        {
+          throw_or_mimic<invalid_option_format_error>(text);
+        }
+
+        const std::string& short_sw = result[2];
+        const std::string& long_sw = result[3];
+
+        return std::pair<std::string, std::string>(short_sw, long_sw);
+      }
+
+      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 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<argument_incorrect_type>(text);
+            }
+          }
+          else
+          {
+            if (u > static_cast<U>((std::numeric_limits<T>::max)()))
+            {
+              throw_or_mimic<argument_incorrect_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<argument_incorrect_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<argument_incorrect_type>(text);
+        }
+
+        const US next = static_cast<US>(result * base + digit);
+        if (result > next)
+        {
+          throw_or_mimic<argument_incorrect_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<argument_incorrect_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<argument_incorrect_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<argument_incorrect_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)
+      {
+        set_default_and_implicit();
+      }
+
+      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);
+  }
+
+} // namespace cxxopts
+
+#endif //CXXOPTS_VALUES_HPP_

src/example.cpp

@@ -24,7 +24,7 @@ THE SOFTWARE.
 
 #include <iostream>
 
-#include "cxxopts.hpp"
+#include "../include/cxxopts_single.hpp"
 
 void
 parse(int argc, const char* argv[])