diff --git a/include/cxxopts.hpp b/include/cxxopts.hpp
index 95f99c3..df21542 100644
--- a/include/cxxopts.hpp
+++ b/include/cxxopts.hpp
@@ -27,34 +27,25 @@ THE SOFTWARE.
 #ifndef CXXOPTS_HPP_INCLUDED
 #define CXXOPTS_HPP_INCLUDED
 
-#include <cstring>
+#include <algorithm>
 #include <exception>
 #include <limits>
 #include <list>
 #include <locale>
 #include <map>
 #include <memory>
+#include <regex>
 #include <sstream>
 #include <string>
 #include <unordered_map>
 #include <unordered_set>
 #include <utility>
 #include <vector>
-#include <algorithm>
 
 #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
-
-#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
@@ -580,168 +571,6 @@ struct ArguDesc {
   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 {
 
@@ -838,9 +667,6 @@ inline ArguDesc ParseArgument(const char *arg, bool &matched)
 
   return argu_desc;
 }
-
-#endif  // CXXOPTS_NO_REGEX
-#undef CXXOPTS_NO_REGEX
 } // namespace parser_tool
 
 namespace detail {
@@ -2368,7 +2194,7 @@ OptionParser::parse(int argc, const char* const* argv)
 
   while (current != argc)
   {
-    if (strcmp(argv[current], "--") == 0)
+    if (std::string{argv[current]} == "--")
     {
       consume_remaining = true;
       ++current;