[precompiled] Initial proof-of-concept with App.cpp

- Add C11_COMPILE cmake option that creates a static lib instead of header-only - Add C11_INLINE macro that depends on C11_COMPILE - Split App.hpp into App.hpp and impl/App_inl.hpp - Add App.cpp that compiles App_inl.hpp into an object file - CMake modifications to handle impl headers differently for sinlge-header, headers-only, and compiled versions

[precompiled] Initial proof-of-concept with App.cpp
- Add C11_COMPILE cmake option that creates a static lib instead of header-only - Add C11_INLINE macro that depends on C11_COMPILE - Split App.hpp into App.hpp and impl/App_inl.hpp - Add App.cpp that compiles App_inl.hpp into an object file - CMake modifications to handle impl headers differently for sinlge-header, headers-only, and compiled versions
Daniel Herrera Castro · Henry Schreiner
1 parent c57000e5
Showing 6 changed files with 2233 additions and 1966 deletions
CLI11.hpp.in
CMakeLists.txt
include/CLI/App.hpp
include/CLI/Macros.hpp
include/CLI/impl/App_inl.hpp
src/App.cpp
@@ -62,6 +62,8 @@ namespace {namespace} {{
 {app_hpp}
+{app_inl_hpp}
+
 {config_hpp}
 {formatter_hpp}
@@ -77,6 +77,7 @@ endif()
 option(CLI11_WARNINGS_AS_ERRORS "Turn all warnings into errors (for CI)")
 option(CLI11_SINGLE_FILE "Generate a single header file")
+option(CLI11_PRECOMPILED "Generate a precompiled static library instead of a header-only")
 cmake_dependent_option(CLI11_SANITIZERS "Download the sanitizers CMake config" OFF
                        "NOT CMAKE_VERSION VERSION_LESS 3.11" OFF)
@@ -105,6 +106,11 @@ cmake_dependent_option(
   CLI11_CUDA_TESTS "Build the tests with NVCC to check for warnings there - requires CMake 3.9+"
   OFF "CMAKE_PROJECT_NAME STREQUAL PROJECT_NAME" OFF)
+if(CLI11_PRECOMPILED AND CLI11_SINGLE_FILE)
+  # Sanity check
+  message(FATAL_ERROR "CLI11_PRECOMPILE and CLI11_SINGLE_FILE are mutually exclusive")
+endif()
+
 if(CMAKE_PROJECT_NAME STREQUAL PROJECT_NAME AND NOT DEFINED CMAKE_CXX_STANDARD)
   set(CMAKE_CXX_STANDARD 11)
 endif()
@@ -160,13 +166,35 @@ if(NOT CMAKE_VERSION VERSION_LESS 3.13)
   target_link_options(CLI11_warnings INTERFACE $<$<BOOL:${CLI11_FORCE_LIBCXX}>:-stdlib=libc++>)
 endif()
+# To see in IDE, headers must be listed for target
+set(MAYBE_CONFIGURE_DEPENDS "")
+if(CMAKE_PROJECT_NAME STREQUAL PROJECT_NAME AND NOT CMAKE_VERSION VERSION_LESS 3.12)
+  list(INSERT MAYBE_CONFIGURE_DEPENDS 0 CONFIGURE_DEPENDS)
+endif()
+
+file(GLOB CLI11_headers ${MAYBE_CONFIGURE_DEPENDS} "${PROJECT_SOURCE_DIR}/include/CLI/*.hpp")
+file(GLOB CLI11_impl_headers ${MAYBE_CONFIGURE_DEPENDS}
+     "${PROJECT_SOURCE_DIR}/include/CLI/impl/*.hpp")
+
+if(CLI11_PRECOMPILED)
+  # Create static lib
+  file(GLOB CLI11_precompile_sources "${PROJECT_SOURCE_DIR}/src/*.cpp")
+  add_library(CLI11 STATIC ${CLI11_headers} ${CLI11_impl_headers} ${CLI11_precompile_sources})
+  target_compile_definitions(CLI11 PUBLIC -DCLI11_COMPILE)
+
+  set(PUBLIC_OR_INTERFACE PUBLIC)
+else()
+  add_library(CLI11 INTERFACE)
+  set(PUBLIC_OR_INTERFACE INTERFACE)
+endif()
+
 # Allow IDE's to group targets into folders
-add_library(CLI11 INTERFACE)
 add_library(CLI11::CLI11 ALIAS CLI11) # for add_subdirectory calls
 # Duplicated because CMake adds the current source dir if you don't.
-target_include_directories(CLI11 INTERFACE $<BUILD_INTERFACE:${CMAKE_CURRENT_SOURCE_DIR}/include>
-                                           $<INSTALL_INTERFACE:include>)
+target_include_directories(
+  CLI11 ${PUBLIC_OR_INTERFACE} $<BUILD_INTERFACE:${CMAKE_CURRENT_SOURCE_DIR}/include>
+  $<INSTALL_INTERFACE:include>)
 if(CMAKE_VERSION VERSION_LESS 3.8)
   # This might not be a complete list
@@ -184,14 +212,6 @@ else()
   target_compile_features(CLI11 INTERFACE cxx_std_11)
 endif()
-# To see in IDE, headers must be listed for target
-set(header-patterns "${PROJECT_SOURCE_DIR}/include/CLI/*")
-if(CMAKE_PROJECT_NAME STREQUAL PROJECT_NAME AND NOT CMAKE_VERSION VERSION_LESS 3.12)
-  list(INSERT header-patterns 0 CONFIGURE_DEPENDS)
-endif()
-
-file(GLOB CLI11_headers ${header-patterns})
-
 # Allow tests to be run on CUDA
 if(CLI11_CUDA_TESTS)
   enable_language(CUDA)
@@ -202,7 +222,10 @@ endif()
 # This folder should be installed
 if(CLI11_INSTALL)
-  install(DIRECTORY "${PROJECT_SOURCE_DIR}/include/" DESTINATION "${CMAKE_INSTALL_INCLUDEDIR}")
+  install(FILES ${CLI11_headers} DESTINATION "${CMAKE_INSTALL_INCLUDEDIR}/CLI")
+  if(NOT CLI11_COMPILE)
+    install(FILES ${CLI11_impl_headers} DESTINATION "${CMAKE_INSTALL_INCLUDEDIR}/CLI/impl")
+  endif()
   # Make an export target
   install(TARGETS CLI11 EXPORT CLI11Targets)
@@ -257,9 +280,10 @@ if(CLI11_SINGLE_FILE)
     OUTPUT "${CMAKE_CURRENT_BINARY_DIR}/include/CLI11.hpp"
     COMMAND
       Python::Interpreter "${CMAKE_CURRENT_SOURCE_DIR}/scripts/MakeSingleHeader.py"
-      ${CLI11_headers} --main "${CMAKE_CURRENT_SOURCE_DIR}/CLI11.hpp.in" --output
-      "${CMAKE_CURRENT_BINARY_DIR}/include/CLI11.hpp" --version "${CLI11_VERSION}"
-    DEPENDS "${CMAKE_CURRENT_SOURCE_DIR}/include/CLI/CLI.hpp" ${CLI11_headers})
+      ${CLI11_headers} ${CLI11_impl_headers} --main "${CMAKE_CURRENT_SOURCE_DIR}/CLI11.hpp.in"
+      --output "${CMAKE_CURRENT_BINARY_DIR}/include/CLI11.hpp" --version "${CLI11_VERSION}"
+    DEPENDS "${CMAKE_CURRENT_SOURCE_DIR}/include/CLI/CLI.hpp" ${CLI11_headers}
+            ${CLI11_impl_headers})
   add_custom_target(CLI11-generate-single-file ALL
                     DEPENDS "${CMAKE_CURRENT_BINARY_DIR}/include/CLI11.hpp")
   set_property(TARGET CLI11-generate-single-file PROPERTY FOLDER "Scripts")
@@ -282,39 +282,7 @@ class App {
     ///@}
     /// Special private constructor for subcommand
-    App(std::string app_description, std::string app_name, App *parent)
-        : name_(std::move(app_name)), description_(std::move(app_description)), parent_(parent) {
-        // Inherit if not from a nullptr
-        if(parent_ != nullptr) {
-            if(parent_->help_ptr_ != nullptr)
-                set_help_flag(parent_->help_ptr_->get_name(false, true), parent_->help_ptr_->get_description());
-            if(parent_->help_all_ptr_ != nullptr)
-                set_help_all_flag(parent_->help_all_ptr_->get_name(false, true),
-                                  parent_->help_all_ptr_->get_description());
-
-            /// OptionDefaults
-            option_defaults_ = parent_->option_defaults_;
-
-            // INHERITABLE
-            failure_message_ = parent_->failure_message_;
-            allow_extras_ = parent_->allow_extras_;
-            allow_config_extras_ = parent_->allow_config_extras_;
-            prefix_command_ = parent_->prefix_command_;
-            immediate_callback_ = parent_->immediate_callback_;
-            ignore_case_ = parent_->ignore_case_;
-            ignore_underscore_ = parent_->ignore_underscore_;
-            fallthrough_ = parent_->fallthrough_;
-            validate_positionals_ = parent_->validate_positionals_;
-            validate_optional_arguments_ = parent_->validate_optional_arguments_;
-            configurable_ = parent_->configurable_;
-            allow_windows_style_options_ = parent_->allow_windows_style_options_;
-            group_ = parent_->group_;
-            footer_ = parent_->footer_;
-            formatter_ = parent_->formatter_;
-            config_formatter_ = parent_->config_formatter_;
-            require_subcommand_max_ = parent_->require_subcommand_max_;
-        }
-    }
+    App(std::string app_description, std::string app_name, App *parent);
   public:
     /// @name Basic
@@ -369,41 +337,10 @@ class App {
     }
     /// Set a name for the app (empty will use parser to set the name)
-    App *name(std::string app_name = "") {
-
-        if(parent_ != nullptr) {
-            auto oname = name_;
-            name_ = app_name;
-            const auto &res = _compare_subcommand_names(*this, *_get_fallthrough_parent());
-            if(!res.empty()) {
-                name_ = oname;
-                throw(OptionAlreadyAdded(app_name + " conflicts with existing subcommand names"));
-            }
-        } else {
-            name_ = app_name;
-        }
-        has_automatic_name_ = false;
-        return this;
-    }
+    App *name(std::string app_name = "");
     /// Set an alias for the app
-    App *alias(std::string app_name) {
-        if(app_name.empty() || !detail::valid_alias_name_string(app_name)) {
-            throw IncorrectConstruction("Aliases may not be empty or contain newlines or null characters");
-        }
-        if(parent_ != nullptr) {
-            aliases_.push_back(app_name);
-            const auto &res = _compare_subcommand_names(*this, *_get_fallthrough_parent());
-            if(!res.empty()) {
-                aliases_.pop_back();
-                throw(OptionAlreadyAdded("alias already matches an existing subcommand: " + app_name));
-            }
-        } else {
-            aliases_.push_back(app_name);
-        }
-
-        return this;
-    }
+    App *alias(std::string app_name);
     /// Remove the error when extras are left over on the command line.
     App *allow_extras(bool allow = true) {
@@ -452,17 +389,7 @@ class App {
     }
     /// Set the subcommand callback to be executed immediately on subcommand completion
-    App *immediate_callback(bool immediate = true) {
-        immediate_callback_ = immediate;
-        if(immediate_callback_) {
-            if(final_callback_ && !(parse_complete_callback_)) {
-                std::swap(final_callback_, parse_complete_callback_);
-            }
-        } else if(!(final_callback_) && parse_complete_callback_) {
-            std::swap(final_callback_, parse_complete_callback_);
-        }
-        return this;
-    }
+    App *immediate_callback(bool immediate = true);
     /// Set the subcommand to validate positional arguments before assigning
     App *validate_positionals(bool validate = true) {
@@ -500,19 +427,7 @@ class App {
     }
     /// Ignore case. Subcommands inherit value.
-    App *ignore_case(bool value = true) {
-        if(value && !ignore_case_) {
-            ignore_case_ = true;
-            auto *p = (parent_ != nullptr) ? _get_fallthrough_parent() : this;
-            const auto &match = _compare_subcommand_names(*this, *p);
-            if(!match.empty()) {
-                ignore_case_ = false;  // we are throwing so need to be exception invariant
-                throw OptionAlreadyAdded("ignore case would cause subcommand name conflicts: " + match);
-            }
-        }
-        ignore_case_ = value;
-        return this;
-    }
+    App *ignore_case(bool value = true);
     /// Allow windows style options, such as `/opt`. First matching short or long name used. Subcommands inherit
     /// value.
@@ -534,19 +449,7 @@ class App {
     }
     /// Ignore underscore. Subcommands inherit value.
-    App *ignore_underscore(bool value = true) {
-        if(value && !ignore_underscore_) {
-            ignore_underscore_ = true;
-            auto *p = (parent_ != nullptr) ? _get_fallthrough_parent() : this;
-            const auto &match = _compare_subcommand_names(*this, *p);
-            if(!match.empty()) {
-                ignore_underscore_ = false;
-                throw OptionAlreadyAdded("ignore underscore would cause subcommand name conflicts: " + match);
-            }
-        }
-        ignore_underscore_ = value;
-        return this;
-    }
+    App *ignore_underscore(bool value = true);
     /// Set the help formatter
     App *formatter(std::shared_ptr<FormatterBase> fmt) {
@@ -594,42 +497,7 @@ class App {
                        callback_t option_callback,
                        std::string option_description = "",
                        bool defaulted = false,
-                       std::function<std::string()> func = {}) {
-        Option myopt{option_name, option_description, option_callback, this};
-
-        if(std::find_if(std::begin(options_), std::end(options_), [&myopt](const Option_p &v) {
-               return *v == myopt;
-           }) == std::end(options_)) {
-            options_.emplace_back();
-            Option_p &option = options_.back();
-            option.reset(new Option(option_name, option_description, option_callback, this));
-
-            // Set the default string capture function
-            option->default_function(func);
-
-            // For compatibility with CLI11 1.7 and before, capture the default string here
-            if(defaulted)
-                option->capture_default_str();
-
-            // Transfer defaults to the new option
-            option_defaults_.copy_to(option.get());
-
-            // Don't bother to capture if we already did
-            if(!defaulted && option->get_always_capture_default())
-                option->capture_default_str();
-
-            return option.get();
-        }
-        // we know something matches now find what it is so we can produce more error information
-        for(auto &opt : options_) {
-            const auto &matchname = opt->matching_name(myopt);
-            if(!matchname.empty()) {
-                throw(OptionAlreadyAdded("added option matched existing option name: " + matchname));
-            }
-        }
-        // this line should not be reached the above loop should trigger the throw
-        throw(OptionAlreadyAdded("added option matched existing option name"));  // LCOV_EXCL_LINE
-    }
+                       std::function<std::string()> func = {});
     /// Add option for assigning to a variable
     template <typename AssignTo,
@@ -711,103 +579,24 @@ class App {
     }
     /// Set a help flag, replace the existing one if present
-    Option *set_help_flag(std::string flag_name = "", const std::string &help_description = "") {
-        // take flag_description by const reference otherwise add_flag tries to assign to help_description
-        if(help_ptr_ != nullptr) {
-            remove_option(help_ptr_);
-            help_ptr_ = nullptr;
-        }
-
-        // Empty name will simply remove the help flag
-        if(!flag_name.empty()) {
-            help_ptr_ = add_flag(flag_name, help_description);
-            help_ptr_->configurable(false);
-        }
-
-        return help_ptr_;
-    }
+    Option *set_help_flag(std::string flag_name = "", const std::string &help_description = "");
     /// Set a help all flag, replaced the existing one if present
-    Option *set_help_all_flag(std::string help_name = "", const std::string &help_description = "") {
-        // take flag_description by const reference otherwise add_flag tries to assign to flag_description
-        if(help_all_ptr_ != nullptr) {
-            remove_option(help_all_ptr_);
-            help_all_ptr_ = nullptr;
-        }
-
-        // Empty name will simply remove the help all flag
-        if(!help_name.empty()) {
-            help_all_ptr_ = add_flag(help_name, help_description);
-            help_all_ptr_->configurable(false);
-        }
-
-        return help_all_ptr_;
-    }
+    Option *set_help_all_flag(std::string help_name = "", const std::string &help_description = "");
     /// Set a version flag and version display string, replace the existing one if present
     Option *set_version_flag(std::string flag_name = "",
                              const std::string &versionString = "",
-                             const std::string &version_help = "Display program version information and exit") {
-        // take flag_description by const reference otherwise add_flag tries to assign to version_description
-        if(version_ptr_ != nullptr) {
-            remove_option(version_ptr_);
-            version_ptr_ = nullptr;
-        }
+                             const std::string &version_help = "Display program version information and exit");
-        // Empty name will simply remove the version flag
-        if(!flag_name.empty()) {
-            version_ptr_ = add_flag_callback(
-                flag_name, [versionString]() { throw(CLI::CallForVersion(versionString, 0)); }, version_help);
-            version_ptr_->configurable(false);
-        }
-
-        return version_ptr_;
-    }
     /// Generate the version string through a callback function
     Option *set_version_flag(std::string flag_name,
                              std::function<std::string()> vfunc,
-                             const std::string &version_help = "Display program version information and exit") {
-        if(version_ptr_ != nullptr) {
-            remove_option(version_ptr_);
-            version_ptr_ = nullptr;
-        }
-
-        // Empty name will simply remove the version flag
-        if(!flag_name.empty()) {
-            version_ptr_ = add_flag_callback(
-                flag_name, [vfunc]() { throw(CLI::CallForVersion(vfunc(), 0)); }, version_help);
-            version_ptr_->configurable(false);
-        }
-
-        return version_ptr_;
-    }
+                             const std::string &version_help = "Display program version information and exit");
   private:
     /// Internal function for adding a flag
-    Option *_add_flag_internal(std::string flag_name, CLI::callback_t fun, std::string flag_description) {
-        Option *opt = nullptr;
-        if(detail::has_default_flag_values(flag_name)) {
-            // check for default values and if it has them
-            auto flag_defaults = detail::get_default_flag_values(flag_name);
-            detail::remove_default_flag_values(flag_name);
-            opt = add_option(std::move(flag_name), std::move(fun), std::move(flag_description), false);
-            for(const auto &fname : flag_defaults)
-                opt->fnames_.push_back(fname.first);
-            opt->default_flag_values_ = std::move(flag_defaults);
-        } else {
-            opt = add_option(std::move(flag_name), std::move(fun), std::move(flag_description), false);
-        }
-        // flags cannot have positional values
-        if(opt->get_positional()) {
-            auto pos_name = opt->get_name(true);
-            remove_option(opt);
-            throw IncorrectConstruction::PositionalFlag(pos_name);
-        }
-        opt->multi_option_policy(MultiOptionPolicy::TakeLast);
-        opt->expected(0);
-        opt->required(false);
-        return opt;
-    }
+    Option *_add_flag_internal(std::string flag_name, CLI::callback_t fun, std::string flag_description);
   public:
     /// Add a flag with no description or variable assignment
@@ -863,33 +652,12 @@ class App {
     /// Add option for callback that is triggered with a true flag and takes no arguments
     Option *add_flag_callback(std::string flag_name,
                               std::function<void(void)> function,  ///< A function to call, void(void)
-                              std::string flag_description = "") {
-
-        CLI::callback_t fun = [function](const CLI::results_t &res) {
-            bool trigger{false};
-            auto result = CLI::detail::lexical_cast(res[0], trigger);
-            if(result && trigger) {
-                function();
-            }
-            return result;
-        };
-        return _add_flag_internal(flag_name, std::move(fun), std::move(flag_description));
-    }
+                              std::string flag_description = "");
     /// Add option for callback with an integer value
     Option *add_flag_function(std::string flag_name,
                               std::function<void(std::int64_t)> function,  ///< A function to call, void(int)
-                              std::string flag_description = "") {
-
-        CLI::callback_t fun = [function](const CLI::results_t &res) {
-            std::int64_t flag_count{0};
-            CLI::detail::lexical_cast(res[0], flag_count);
-            function(flag_count);
-            return true;
-        };
-        return _add_flag_internal(flag_name, std::move(fun), std::move(flag_description))
-            ->multi_option_policy(MultiOptionPolicy::Sum);
-    }
+                              std::string flag_description = "");
 #ifdef CLI11_CPP14
     /// Add option for callback (C++14 or better only)
@@ -904,50 +672,10 @@ class App {
     Option *set_config(std::string option_name = "",
                        std::string default_filename = "",
                        const std::string &help_message = "Read an ini file",
-                       bool config_required = false) {
-
-        // Remove existing config if present
-        if(config_ptr_ != nullptr) {
-            remove_option(config_ptr_);
-            config_ptr_ = nullptr;  // need to remove the config_ptr completely
-        }
-
-        // Only add config if option passed
-        if(!option_name.empty()) {
-            config_ptr_ = add_option(option_name, help_message);
-            if(config_required) {
-                config_ptr_->required();
-            }
-            if(!default_filename.empty()) {
-                config_ptr_->default_str(std::move(default_filename));
-            }
-            config_ptr_->configurable(false);
-        }
-
-        return config_ptr_;
-    }
+                       bool config_required = false);
     /// Removes an option from the App. Takes an option pointer. Returns true if found and removed.
-    bool remove_option(Option *opt) {
-        // Make sure no links exist
-        for(Option_p &op : options_) {
-            op->remove_needs(opt);
-            op->remove_excludes(opt);
-        }
-
-        if(help_ptr_ == opt)
-            help_ptr_ = nullptr;
-        if(help_all_ptr_ == opt)
-            help_all_ptr_ = nullptr;
-
-        auto iterator =
-            std::find_if(std::begin(options_), std::end(options_), [opt](const Option_p &v) { return v.get() == opt; });
-        if(iterator != std::end(options_)) {
-            options_.erase(iterator);
-            return true;
-        }
-        return false;
-    }
+    bool remove_option(Option *opt);
     /// creates an option group as part of the given app
     template <typename T = Option_group>
@@ -968,119 +696,35 @@ class App {
     ///@{
     /// Add a subcommand. Inherits INHERITABLE and OptionDefaults, and help flag
-    App *add_subcommand(std::string subcommand_name = "", std::string subcommand_description = "") {
-        if(!subcommand_name.empty() && !detail::valid_name_string(subcommand_name)) {
-            if(!detail::valid_first_char(subcommand_name[0])) {
-                throw IncorrectConstruction(
-                    "Subcommand name starts with invalid character, '!' and '-' are not allowed");
-            }
-            for(auto c : subcommand_name) {
-                if(!detail::valid_later_char(c)) {
-                    throw IncorrectConstruction(std::string("Subcommand name contains invalid character ('") + c +
-                                                "'), all characters are allowed except"
-                                                "'=',':','{','}', and ' '");
-                }
-            }
-        }
-        CLI::App_p subcom = std::shared_ptr<App>(new App(std::move(subcommand_description), subcommand_name, this));
-        return add_subcommand(std::move(subcom));
-    }
+    App *add_subcommand(std::string subcommand_name = "", std::string subcommand_description = "");
     /// Add a previously created app as a subcommand
-    App *add_subcommand(CLI::App_p subcom) {
-        if(!subcom)
-            throw IncorrectConstruction("passed App is not valid");
-        auto *ckapp = (name_.empty() && parent_ != nullptr) ? _get_fallthrough_parent() : this;
-        const auto &mstrg = _compare_subcommand_names(*subcom, *ckapp);
-        if(!mstrg.empty()) {
-            throw(OptionAlreadyAdded("subcommand name or alias matches existing subcommand: " + mstrg));
-        }
-        subcom->parent_ = this;
-        subcommands_.push_back(std::move(subcom));
-        return subcommands_.back().get();
-    }
+    App *add_subcommand(CLI::App_p subcom);
     /// Removes a subcommand from the App. Takes a subcommand pointer. Returns true if found and removed.
-    bool remove_subcommand(App *subcom) {
-        // Make sure no links exist
-        for(App_p &sub : subcommands_) {
-            sub->remove_excludes(subcom);
-            sub->remove_needs(subcom);
-        }
+    bool remove_subcommand(App *subcom);
-        auto iterator = std::find_if(
-            std::begin(subcommands_), std::end(subcommands_), [subcom](const App_p &v) { return v.get() == subcom; });
-        if(iterator != std::end(subcommands_)) {
-            subcommands_.erase(iterator);
-            return true;
-        }
-        return false;
-    }
     /// Check to see if a subcommand is part of this command (doesn't have to be in command line)
     /// returns the first subcommand if passed a nullptr
-    App *get_subcommand(const App *subcom) const {
-        if(subcom == nullptr)
-            throw OptionNotFound("nullptr passed");
-        for(const App_p &subcomptr : subcommands_)
-            if(subcomptr.get() == subcom)
-                return subcomptr.get();
-        throw OptionNotFound(subcom->get_name());
-    }
+    App *get_subcommand(const App *subcom) const;
     /// Check to see if a subcommand is part of this command (text version)
-    CLI11_NODISCARD App *get_subcommand(std::string subcom) const {
-        auto *subc = _find_subcommand(subcom, false, false);
-        if(subc == nullptr)
-            throw OptionNotFound(subcom);
-        return subc;
-    }
+    CLI11_NODISCARD App *get_subcommand(std::string subcom) const;
+
     /// Get a pointer to subcommand by index
-    CLI11_NODISCARD App *get_subcommand(int index = 0) const {
-        if(index >= 0) {
-            auto uindex = static_cast<unsigned>(index);
-            if(uindex < subcommands_.size())
-                return subcommands_[uindex].get();
-        }
-        throw OptionNotFound(std::to_string(index));
-    }
+    CLI11_NODISCARD App *get_subcommand(int index = 0) const;
     /// Check to see if a subcommand is part of this command and get a shared_ptr to it
-    CLI::App_p get_subcommand_ptr(App *subcom) const {
-        if(subcom == nullptr)
-            throw OptionNotFound("nullptr passed");
-        for(const App_p &subcomptr : subcommands_)
-            if(subcomptr.get() == subcom)
-                return subcomptr;
-        throw OptionNotFound(subcom->get_name());
-    }
+    CLI::App_p get_subcommand_ptr(App *subcom) const;
     /// Check to see if a subcommand is part of this command (text version)
-    CLI11_NODISCARD CLI::App_p get_subcommand_ptr(std::string subcom) const {
-        for(const App_p &subcomptr : subcommands_)
-            if(subcomptr->check_name(subcom))
-                return subcomptr;
-        throw OptionNotFound(subcom);
-    }
+    CLI11_NODISCARD CLI::App_p get_subcommand_ptr(std::string subcom) const;
     /// Get an owning pointer to subcommand by index
-    CLI11_NODISCARD CLI::App_p get_subcommand_ptr(int index = 0) const {
-        if(index >= 0) {
-            auto uindex = static_cast<unsigned>(index);
-            if(uindex < subcommands_.size())
-                return subcommands_[uindex];
-        }
-        throw OptionNotFound(std::to_string(index));
-    }
+    CLI11_NODISCARD CLI::App_p get_subcommand_ptr(int index = 0) const;
     /// Check to see if an option group is part of this App
-    CLI11_NODISCARD App *get_option_group(std::string group_name) const {
-        for(const App_p &app : subcommands_) {
-            if(app->name_.empty() && app->group_ == group_name) {
-                return app.get();
-            }
-        }
-        throw OptionNotFound(group_name);
-    }
+    CLI11_NODISCARD App *get_option_group(std::string group_name) const;
     /// No argument version of count counts the number of times this subcommand was
     /// passed in. The main app will return 1. Unnamed subcommands will also return 1 unless
@@ -1089,19 +733,7 @@ class App {
     /// Get a count of all the arguments processed in options and subcommands, this excludes arguments which were
     /// treated as extras.
-    CLI11_NODISCARD std::size_t count_all() const {
-        std::size_t cnt{0};
-        for(const auto &opt : options_) {
-            cnt += opt->count();
-        }
-        for(const auto &sub : subcommands_) {
-            cnt += sub->count_all();
-        }
-        if(!get_name().empty()) {  // for named subcommands add the number of times the subcommand was called
-            cnt += parsed_;
-        }
-        return cnt;
-    }
+    CLI11_NODISCARD std::size_t count_all() const;
     /// Changes the group membership
     App *group(std::string group_name) {
@@ -1192,153 +824,34 @@ class App {
     ///@{
     //
     /// Reset the parsed data
-    void clear() {
-
-        parsed_ = 0;
-        pre_parse_called_ = false;
-
-        missing_.clear();
-        parsed_subcommands_.clear();
-        for(const Option_p &opt : options_) {
-            opt->clear();
-        }
-        for(const App_p &subc : subcommands_) {
-            subc->clear();
-        }
-    }
+    void clear();
     /// Parses the command line - throws errors.
     /// This must be called after the options are in but before the rest of the program.
-    void parse(int argc, const char *const *argv) {
-        // If the name is not set, read from command line
-        if(name_.empty() || has_automatic_name_) {
-            has_automatic_name_ = true;
-            name_ = argv[0];
-        }
-
-        std::vector<std::string> args;
-        args.reserve(static_cast<std::size_t>(argc) - 1U);
-        for(auto i = static_cast<std::size_t>(argc) - 1U; i > 0U; --i)
-            args.emplace_back(argv[i]);
-        parse(std::move(args));
-    }
+    void parse(int argc, const char *const *argv);
     /// Parse a single string as if it contained command line arguments.
     /// This function splits the string into arguments then calls parse(std::vector<std::string> &)
     /// the function takes an optional boolean argument specifying if the programName is included in the string to
     /// process
-    void parse(std::string commandline, bool program_name_included = false) {
-
-        if(program_name_included) {
-            auto nstr = detail::split_program_name(commandline);
-            if((name_.empty()) || (has_automatic_name_)) {
-                has_automatic_name_ = true;
-                name_ = nstr.first;
-            }
-            commandline = std::move(nstr.second);
-        } else {
-            detail::trim(commandline);
-        }
-        // the next section of code is to deal with quoted arguments after an '=' or ':' for windows like operations
-        if(!commandline.empty()) {
-            commandline = detail::find_and_modify(commandline, "=", detail::escape_detect);
-            if(allow_windows_style_options_)
-                commandline = detail::find_and_modify(commandline, ":", detail::escape_detect);
-        }
-
-        auto args = detail::split_up(std::move(commandline));
-        // remove all empty strings
-        args.erase(std::remove(args.begin(), args.end(), std::string{}), args.end());
-        std::reverse(args.begin(), args.end());
-
-        parse(std::move(args));
-    }
+    void parse(std::string commandline, bool program_name_included = false);
     /// The real work is done here. Expects a reversed vector.
     /// Changes the vector to the remaining options.
-    void parse(std::vector<std::string> &args) {
-        // Clear if parsed
-        if(parsed_ > 0)
-            clear();
-
-        // parsed_ is incremented in commands/subcommands,
-        // but placed here to make sure this is cleared when
-        // running parse after an error is thrown, even by _validate or _configure.
-        parsed_ = 1;
-        _validate();
-        _configure();
-        // set the parent as nullptr as this object should be the top now
-        parent_ = nullptr;
-        parsed_ = 0;
-
-        _parse(args);
-        run_callback();
-    }
+    void parse(std::vector<std::string> &args);
     /// The real work is done here. Expects a reversed vector.
-    void parse(std::vector<std::string> &&args) {
-        // Clear if parsed
-        if(parsed_ > 0)
-            clear();
-
-        // parsed_ is incremented in commands/subcommands,
-        // but placed here to make sure this is cleared when
-        // running parse after an error is thrown, even by _validate or _configure.
-        parsed_ = 1;
-        _validate();
-        _configure();
-        // set the parent as nullptr as this object should be the top now
-        parent_ = nullptr;
-        parsed_ = 0;
-
-        _parse(std::move(args));
-        run_callback();
-    }
-
-    void parse_from_stream(std::istream &input) {
-        if(parsed_ == 0) {
-            _validate();
-            _configure();
-            // set the parent as nullptr as this object should be the top now
-        }
+    void parse(std::vector<std::string> &&args);
+
+    void parse_from_stream(std::istream &input);
-        _parse_stream(input);
-        run_callback();
-    }
     /// Provide a function to print a help message. The function gets access to the App pointer and error.
     void failure_message(std::function<std::string(const App *, const Error &e)> function) {
         failure_message_ = function;
     }
     /// Print a nice error message and return the exit code
-    int exit(const Error &e, std::ostream &out = std::cout, std::ostream &err = std::cerr) const {
-
-        /// Avoid printing anything if this is a CLI::RuntimeError
-        if(e.get_name() == "RuntimeError")
-            return e.get_exit_code();
-
-        if(e.get_name() == "CallForHelp") {
-            out << help();
-            return e.get_exit_code();
-        }
-
-        if(e.get_name() == "CallForAllHelp") {
-            out << help("", AppFormatMode::All);
-            return e.get_exit_code();
-        }
-
-        if(e.get_name() == "CallForVersion") {
-            out << e.what() << std::endl;
-            return e.get_exit_code();
-        }
-
-        if(e.get_exit_code() != static_cast<int>(ExitCodes::Success)) {
-            if(failure_message_)
-                err << failure_message_(this, e) << std::flush;
-        }
-
-        return e.get_exit_code();
-    }
+    int exit(const Error &e, std::ostream &out = std::cout, std::ostream &err = std::cerr) const;
     ///@}
     /// @name Post parsing
@@ -1353,38 +866,11 @@ class App {
     /// Get a filtered subcommand pointer list from the original definition list. An empty function will provide all
     /// subcommands (const)
-    std::vector<const App *> get_subcommands(const std::function<bool(const App *)> &filter) const {
-        std::vector<const App *> subcomms(subcommands_.size());
-        std::transform(std::begin(subcommands_), std::end(subcommands_), std::begin(subcomms), [](const App_p &v) {
-            return v.get();
-        });
-
-        if(filter) {
-            subcomms.erase(std::remove_if(std::begin(subcomms),
-                                          std::end(subcomms),
-                                          [&filter](const App *app) { return !filter(app); }),
-                           std::end(subcomms));
-        }
-
-        return subcomms;
-    }
+    std::vector<const App *> get_subcommands(const std::function<bool(const App *)> &filter) const;
     /// Get a filtered subcommand pointer list from the original definition list. An empty function will provide all
     /// subcommands
-    std::vector<App *> get_subcommands(const std::function<bool(App *)> &filter) {
-        std::vector<App *> subcomms(subcommands_.size());
-        std::transform(std::begin(subcommands_), std::end(subcommands_), std::begin(subcomms), [](const App_p &v) {
-            return v.get();
-        });
-
-        if(filter) {
-            subcomms.erase(
-                std::remove_if(std::begin(subcomms), std::end(subcomms), [&filter](App *app) { return !filter(app); }),
-                std::end(subcomms));
-        }
-
-        return subcomms;
-    }
+    std::vector<App *> get_subcommands(const std::function<bool(App *)> &filter);
     /// Check to see if given subcommand was selected
     bool got_subcommand(const App *subcom) const {
@@ -1442,47 +928,16 @@ class App {
     }
     /// Removes an option from the excludes list of this subcommand
-    bool remove_excludes(Option *opt) {
-        auto iterator = std::find(std::begin(exclude_options_), std::end(exclude_options_), opt);
-        if(iterator == std::end(exclude_options_)) {
-            return false;
-        }
-        exclude_options_.erase(iterator);
-        return true;
-    }
+    bool remove_excludes(Option *opt);
     /// Removes a subcommand from the excludes list of this subcommand
-    bool remove_excludes(App *app) {
-        auto iterator = std::find(std::begin(exclude_subcommands_), std::end(exclude_subcommands_), app);
-        if(iterator == std::end(exclude_subcommands_)) {
-            return false;
-        }
-        auto *other_app = *iterator;
-        exclude_subcommands_.erase(iterator);
-        other_app->remove_excludes(this);
-        return true;
-    }
+    bool remove_excludes(App *app);
     /// Removes an option from the needs list of this subcommand
-    bool remove_needs(Option *opt) {
-        auto iterator = std::find(std::begin(need_options_), std::end(need_options_), opt);
-        if(iterator == std::end(need_options_)) {
-            return false;
-        }
-        need_options_.erase(iterator);
-        return true;
-    }
+    bool remove_needs(Option *opt);
     /// Removes a subcommand from the needs list of this subcommand
-    bool remove_needs(App *app) {
-        auto iterator = std::find(std::begin(need_subcommands_), std::end(need_subcommands_), app);
-        if(iterator == std::end(need_subcommands_)) {
-            return false;
-        }
-        need_subcommands_.erase(iterator);
-        return true;
-    }
-
+    bool remove_needs(App *app);
     ///@}
     /// @name Help
     ///@{
@@ -1505,37 +960,10 @@ class App {
     /// Makes a help message, using the currently configured formatter
     /// Will only do one subcommand at a time
-    CLI11_NODISCARD std::string help(std::string prev = "", AppFormatMode mode = AppFormatMode::Normal) const {
-        if(prev.empty())
-            prev = get_name();
-        else
-            prev += " " + get_name();
-
-        // Delegate to subcommand if needed
-        auto selected_subcommands = get_subcommands();
-        if(!selected_subcommands.empty()) {
-            return selected_subcommands.at(0)->help(prev, mode);
-        }
-        return formatter_->make_help(this, prev, mode);
-    }
+    CLI11_NODISCARD std::string help(std::string prev = "", AppFormatMode mode = AppFormatMode::Normal) const;
     /// Displays a version string
-    CLI11_NODISCARD std::string version() const {
-        std::string val;
-        if(version_ptr_ != nullptr) {
-            auto rv = version_ptr_->results();
-            version_ptr_->clear();
-            version_ptr_->add_result("true");
-            try {
-                version_ptr_->run_callback();
-            } catch(const CLI::CallForVersion &cfv) {
-                val = cfv.what();
-            }
-            version_ptr_->clear();
-            version_ptr_->add_result(rv);
-        }
-        return val;
-    }
+    CLI11_NODISCARD std::string version() const;
     ///@}
     /// @name Getters
     ///@{
@@ -1566,75 +994,16 @@ class App {
     }
     /// Get the list of options (user facing function, so returns raw pointers), has optional filter function
-    std::vector<const Option *> get_options(const std::function<bool(const Option *)> filter = {}) const {
-        std::vector<const Option *> options(options_.size());
-        std::transform(std::begin(options_), std::end(options_), std::begin(options), [](const Option_p &val) {
-            return val.get();
-        });
-
-        if(filter) {
-            options.erase(std::remove_if(std::begin(options),
-                                         std::end(options),
-                                         [&filter](const Option *opt) { return !filter(opt); }),
-                          std::end(options));
-        }
-
-        return options;
-    }
+    std::vector<const Option *> get_options(const std::function<bool(const Option *)> filter = {}) const;
     /// Non-const version of the above
-    std::vector<Option *> get_options(const std::function<bool(Option *)> filter = {}) {
-        std::vector<Option *> options(options_.size());
-        std::transform(std::begin(options_), std::end(options_), std::begin(options), [](const Option_p &val) {
-            return val.get();
-        });
-
-        if(filter) {
-            options.erase(
-                std::remove_if(std::begin(options), std::end(options), [&filter](Option *opt) { return !filter(opt); }),
-                std::end(options));
-        }
-
-        return options;
-    }
+    std::vector<Option *> get_options(const std::function<bool(Option *)> filter = {});
     /// Get an option by name (noexcept non-const version)
-    Option *get_option_no_throw(std::string option_name) noexcept {
-        for(Option_p &opt : options_) {
-            if(opt->check_name(option_name)) {
-                return opt.get();
-            }
-        }
-        for(auto &subc : subcommands_) {
-            // also check down into nameless subcommands
-            if(subc->get_name().empty()) {
-                auto *opt = subc->get_option_no_throw(option_name);
-                if(opt != nullptr) {
-                    return opt;
-                }
-            }
-        }
-        return nullptr;
-    }
+    Option *get_option_no_throw(std::string option_name) noexcept;
     /// Get an option by name (noexcept const version)
-    CLI11_NODISCARD const Option *get_option_no_throw(std::string option_name) const noexcept {
-        for(const Option_p &opt : options_) {
-            if(opt->check_name(option_name)) {
-                return opt.get();
-            }
-        }
-        for(const auto &subc : subcommands_) {
-            // also check down into nameless subcommands
-            if(subc->get_name().empty()) {
-                auto *opt = subc->get_option_no_throw(option_name);
-                if(opt != nullptr) {
-                    return opt;
-                }
-            }
-        }
-        return nullptr;
-    }
+    CLI11_NODISCARD const Option *get_option_no_throw(std::string option_name) const noexcept;
     /// Get an option by name
     CLI11_NODISCARD const Option *get_option(std::string option_name) const {
@@ -1769,116 +1138,25 @@ class App {
     }
     /// Get a display name for an app
-    CLI11_NODISCARD std::string get_display_name(bool with_aliases = false) const {
-        if(name_.empty()) {
-            return std::string("[Option Group: ") + get_group() + "]";
-        }
-        if(aliases_.empty() || !with_aliases) {
-            return name_;
-        }
-        std::string dispname = name_;
-        for(const auto &lalias : aliases_) {
-            dispname.push_back(',');
-            dispname.push_back(' ');
-            dispname.append(lalias);
-        }
-        return dispname;
-    }
+    CLI11_NODISCARD std::string get_display_name(bool with_aliases = false) const;
     /// Check the name, case insensitive and underscore insensitive if set
-    CLI11_NODISCARD bool check_name(std::string name_to_check) const {
-        std::string local_name = name_;
-        if(ignore_underscore_) {
-            local_name = detail::remove_underscore(name_);
-            name_to_check = detail::remove_underscore(name_to_check);
-        }
-        if(ignore_case_) {
-            local_name = detail::to_lower(name_);
-            name_to_check = detail::to_lower(name_to_check);
-        }
-
-        if(local_name == name_to_check) {
-            return true;
-        }
-        for(auto les : aliases_) {  // NOLINT(performance-for-range-copy)
-            if(ignore_underscore_) {
-                les = detail::remove_underscore(les);
-            }
-            if(ignore_case_) {
-                les = detail::to_lower(les);
-            }
-            if(les == name_to_check) {
-                return true;
-            }
-        }
-        return false;
-    }
+    CLI11_NODISCARD bool check_name(std::string name_to_check) const;
     /// Get the groups available directly from this option (in order)
-    CLI11_NODISCARD std::vector<std::string> get_groups() const {
-        std::vector<std::string> groups;
-
-        for(const Option_p &opt : options_) {
-            // Add group if it is not already in there
-            if(std::find(groups.begin(), groups.end(), opt->get_group()) == groups.end()) {
-                groups.push_back(opt->get_group());
-            }
-        }
-
-        return groups;
-    }
+    CLI11_NODISCARD std::vector<std::string> get_groups() const;
     /// This gets a vector of pointers with the original parse order
     CLI11_NODISCARD const std::vector<Option *> &parse_order() const { return parse_order_; }
     /// This returns the missing options from the current subcommand
-    CLI11_NODISCARD std::vector<std::string> remaining(bool recurse = false) const {
-        std::vector<std::string> miss_list;
-        for(const std::pair<detail::Classifier, std::string> &miss : missing_) {
-            miss_list.push_back(std::get<1>(miss));
-        }
-        // Get from a subcommand that may allow extras
-        if(recurse) {
-            if(!allow_extras_) {
-                for(const auto &sub : subcommands_) {
-                    if(sub->name_.empty() && !sub->missing_.empty()) {
-                        for(const std::pair<detail::Classifier, std::string> &miss : sub->missing_) {
-                            miss_list.push_back(std::get<1>(miss));
-                        }
-                    }
-                }
-            }
-            // Recurse into subcommands
-
-            for(const App *sub : parsed_subcommands_) {
-                std::vector<std::string> output = sub->remaining(recurse);
-                std::copy(std::begin(output), std::end(output), std::back_inserter(miss_list));
-            }
-        }
-        return miss_list;
-    }
+    CLI11_NODISCARD std::vector<std::string> remaining(bool recurse = false) const;
     /// This returns the missing options in a form ready for processing by another command line program
-    CLI11_NODISCARD std::vector<std::string> remaining_for_passthrough(bool recurse = false) const {
-        std::vector<std::string> miss_list = remaining(recurse);
-        std::reverse(std::begin(miss_list), std::end(miss_list));
-        return miss_list;
-    }
+    CLI11_NODISCARD std::vector<std::string> remaining_for_passthrough(bool recurse = false) const;
     /// This returns the number of remaining options, minus the -- separator
-    CLI11_NODISCARD std::size_t remaining_size(bool recurse = false) const {
-        auto remaining_options = static_cast<std::size_t>(std::count_if(
-            std::begin(missing_), std::end(missing_), [](const std::pair<detail::Classifier, std::string> &val) {
-                return val.first != detail::Classifier::POSITIONAL_MARK;
-            }));
-
-        if(recurse) {
-            for(const App_p &sub : subcommands_) {
-                remaining_options += sub->remaining_size(recurse);
-            }
-        }
-        return remaining_options;
-    }
+    CLI11_NODISCARD std::size_t remaining_size(bool recurse = false) const;
     ///@}
@@ -1887,1147 +1165,118 @@ class App {
     ///
     /// Currently checks to see if multiple positionals exist with unlimited args and checks if the min and max options
     /// are feasible
-    void _validate() const {
-        // count the number of positional only args
-        auto pcount = std::count_if(std::begin(options_), std::end(options_), [](const Option_p &opt) {
-            return opt->get_items_expected_max() >= detail::expected_max_vector_size && !opt->nonpositional();
-        });
-        if(pcount > 1) {
-            auto pcount_req = std::count_if(std::begin(options_), std::end(options_), [](const Option_p &opt) {
-                return opt->get_items_expected_max() >= detail::expected_max_vector_size && !opt->nonpositional() &&
-                       opt->get_required();
-            });
-            if(pcount - pcount_req > 1) {
-                throw InvalidError(name_);
-            }
-        }
-
-        std::size_t nameless_subs{0};
-        for(const App_p &app : subcommands_) {
-            app->_validate();
-            if(app->get_name().empty())
-                ++nameless_subs;
-        }
-
-        if(require_option_min_ > 0) {
-            if(require_option_max_ > 0) {
-                if(require_option_max_ < require_option_min_) {
-                    throw(InvalidError("Required min options greater than required max options",
-                                       ExitCodes::InvalidError));
-                }
-            }
-            if(require_option_min_ > (options_.size() + nameless_subs)) {
-                throw(InvalidError("Required min options greater than number of available options",
-                                   ExitCodes::InvalidError));
-            }
-        }
-    }
+    void _validate() const;
     /// configure subcommands to enable parsing through the current object
     /// set the correct fallthrough and prefix for nameless subcommands and manage the automatic enable or disable
     /// makes sure parent is set correctly
-    void _configure() {
-        if(default_startup == startup_mode::enabled) {
-            disabled_ = false;
-        } else if(default_startup == startup_mode::disabled) {
-            disabled_ = true;
-        }
-        for(const App_p &app : subcommands_) {
-            if(app->has_automatic_name_) {
-                app->name_.clear();
-            }
-            if(app->name_.empty()) {
-                app->fallthrough_ = false;  // make sure fallthrough_ is false to prevent infinite loop
-                app->prefix_command_ = false;
-            }
-            // make sure the parent is set to be this object in preparation for parse
-            app->parent_ = this;
-            app->_configure();
-        }
-    }
+    void _configure();
     /// Internal function to run (App) callback, bottom up
-    void run_callback(bool final_mode = false, bool suppress_final_callback = false) {
-        pre_callback();
-        // in the main app if immediate_callback_ is set it runs the main callback before the used subcommands
-        if(!final_mode && parse_complete_callback_) {
-            parse_complete_callback_();
-        }
-        // run the callbacks for the received subcommands
-        for(App *subc : get_subcommands()) {
-            if(subc->parent_ == this) {
-                subc->run_callback(true, suppress_final_callback);
-            }
-        }
-        // now run callbacks for option_groups
-        for(auto &subc : subcommands_) {
-            if(subc->name_.empty() && subc->count_all() > 0) {
-                subc->run_callback(true, suppress_final_callback);
-            }
-        }
-
-        // finally run the main callback
-        if(final_callback_ && (parsed_ > 0) && (!suppress_final_callback)) {
-            if(!name_.empty() || count_all() > 0 || parent_ == nullptr) {
-                final_callback_();
-            }
-        }
-    }
+    void run_callback(bool final_mode = false, bool suppress_final_callback = false);
     /// Check to see if a subcommand is valid. Give up immediately if subcommand max has been reached.
-    CLI11_NODISCARD bool _valid_subcommand(const std::string &current, bool ignore_used = true) const {
-        // Don't match if max has been reached - but still check parents
-        if(require_subcommand_max_ != 0 && parsed_subcommands_.size() >= require_subcommand_max_) {
-            return parent_ != nullptr && parent_->_valid_subcommand(current, ignore_used);
-        }
-        auto *com = _find_subcommand(current, true, ignore_used);
-        if(com != nullptr) {
-            return true;
-        }
-        // Check parent if exists, else return false
-        return parent_ != nullptr && parent_->_valid_subcommand(current, ignore_used);
-    }
+    CLI11_NODISCARD bool _valid_subcommand(const std::string &current, bool ignore_used = true) const;
     /// Selects a Classifier enum based on the type of the current argument
     CLI11_NODISCARD detail::Classifier _recognize(const std::string &current,
-                                                  bool ignore_used_subcommands = true) const {
-        std::string dummy1, dummy2;
-
-        if(current == "--")
-            return detail::Classifier::POSITIONAL_MARK;
-        if(_valid_subcommand(current, ignore_used_subcommands))
-            return detail::Classifier::SUBCOMMAND;
-        if(detail::split_long(current, dummy1, dummy2))
-            return detail::Classifier::LONG;
-        if(detail::split_short(current, dummy1, dummy2)) {
-            if(dummy1[0] >= '0' && dummy1[0] <= '9') {
-                if(get_option_no_throw(std::string{'-', dummy1[0]}) == nullptr) {
-                    return detail::Classifier::NONE;
-                }
-            }
-            return detail::Classifier::SHORT;
-        }
-        if((allow_windows_style_options_) && (detail::split_windows_style(current, dummy1, dummy2)))
-            return detail::Classifier::WINDOWS_STYLE;
-        if((current == "++") && !name_.empty() && parent_ != nullptr)
-            return detail::Classifier::SUBCOMMAND_TERMINATOR;
-        return detail::Classifier::NONE;
-    }
+                                                  bool ignore_used_subcommands = true) const;
     // The parse function is now broken into several parts, and part of process
     /// Read and process a configuration file (main app only)
-    void _process_config_file() {
-        if(config_ptr_ != nullptr) {
-            bool config_required = config_ptr_->get_required();
-            auto file_given = config_ptr_->count() > 0;
-            auto config_files = config_ptr_->as<std::vector<std::string>>();
-            if(config_files.empty() || config_files.front().empty()) {
-                if(config_required) {
-                    throw FileError::Missing("no specified config file");
-                }
-                return;
-            }
-            for(auto rit = config_files.rbegin(); rit != config_files.rend(); ++rit) {
-                const auto &config_file = *rit;
-                auto path_result = detail::check_path(config_file.c_str());
-                if(path_result == detail::path_type::file) {
-                    try {
-                        std::vector<ConfigItem> values = config_formatter_->from_file(config_file);
-                        _parse_config(values);
-                        if(!file_given) {
-                            config_ptr_->add_result(config_file);
-                        }
-                    } catch(const FileError &) {
-                        if(config_required || file_given)
-                            throw;
-                    }
-                } else if(config_required || file_given) {
-                    throw FileError::Missing(config_file);
-                }
-            }
-        }
-    }
+    void _process_config_file();
     /// Get envname options if not yet passed. Runs on *all* subcommands.
-    void _process_env() {
-        for(const Option_p &opt : options_) {
-            if(opt->count() == 0 && !opt->envname_.empty()) {
-                char *buffer = nullptr;
-                std::string ename_string;
-
-#ifdef _MSC_VER
-                // Windows version
-                std::size_t sz = 0;
-                if(_dupenv_s(&buffer, &sz, opt->envname_.c_str()) == 0 && buffer != nullptr) {
-                    ename_string = std::string(buffer);
-                    free(buffer);
-                }
-#else
-                // This also works on Windows, but gives a warning
-                buffer = std::getenv(opt->envname_.c_str());
-                if(buffer != nullptr)
-                    ename_string = std::string(buffer);
-#endif
-
-                if(!ename_string.empty()) {
-                    opt->add_result(ename_string);
-                }
-            }
-        }
-
-        for(App_p &sub : subcommands_) {
-            if(sub->get_name().empty() || !sub->parse_complete_callback_)
-                sub->_process_env();
-        }
-    }
+    void _process_env();
     /// Process callbacks. Runs on *all* subcommands.
-    void _process_callbacks() {
-
-        for(App_p &sub : subcommands_) {
-            // process the priority option_groups first
-            if(sub->get_name().empty() && sub->parse_complete_callback_) {
-                if(sub->count_all() > 0) {
-                    sub->_process_callbacks();
-                    sub->run_callback();
-                }
-            }
-        }
-
-        for(const Option_p &opt : options_) {
-            if((*opt) && !opt->get_callback_run()) {
-                opt->run_callback();
-            }
-        }
-        for(App_p &sub : subcommands_) {
-            if(!sub->parse_complete_callback_) {
-                sub->_process_callbacks();
-            }
-        }
-    }
+    void _process_callbacks();
     /// Run help flag processing if any are found.
     ///
     /// The flags allow recursive calls to remember if there was a help flag on a parent.
-    void _process_help_flags(bool trigger_help = false, bool trigger_all_help = false) const {
-        const Option *help_ptr = get_help_ptr();
-        const Option *help_all_ptr = get_help_all_ptr();
-
-        if(help_ptr != nullptr && help_ptr->count() > 0)
-            trigger_help = true;
-        if(help_all_ptr != nullptr && help_all_ptr->count() > 0)
-            trigger_all_help = true;
-
-        // If there were parsed subcommands, call those. First subcommand wins if there are multiple ones.
-        if(!parsed_subcommands_.empty()) {
-            for(const App *sub : parsed_subcommands_)
-                sub->_process_help_flags(trigger_help, trigger_all_help);
-
-            // Only the final subcommand should call for help. All help wins over help.
-        } else if(trigger_all_help) {
-            throw CallForAllHelp();
-        } else if(trigger_help) {
-            throw CallForHelp();
-        }
-    }
+    void _process_help_flags(bool trigger_help = false, bool trigger_all_help = false) const;
     /// Verify required options and cross requirements. Subcommands too (only if selected).
-    void _process_requirements() {
-        // check excludes
-        bool excluded{false};
-        std::string excluder;
-        for(const auto &opt : exclude_options_) {
-            if(opt->count() > 0) {
-                excluded = true;
-                excluder = opt->get_name();
-            }
-        }
-        for(const auto &subc : exclude_subcommands_) {
-            if(subc->count_all() > 0) {
-                excluded = true;
-                excluder = subc->get_display_name();
-            }
-        }
-        if(excluded) {
-            if(count_all() > 0) {
-                throw ExcludesError(get_display_name(), excluder);
-            }
-            // if we are excluded but didn't receive anything, just return
-            return;
-        }
-
-        // check excludes
-        bool missing_needed{false};
-        std::string missing_need;
-        for(const auto &opt : need_options_) {
-            if(opt->count() == 0) {
-                missing_needed = true;
-                missing_need = opt->get_name();
-            }
-        }
-        for(const auto &subc : need_subcommands_) {
-            if(subc->count_all() == 0) {
-                missing_needed = true;
-                missing_need = subc->get_display_name();
-            }
-        }
-        if(missing_needed) {
-            if(count_all() > 0) {
-                throw RequiresError(get_display_name(), missing_need);
-            }
-            // if we missing something but didn't have any options, just return
-            return;
-        }
-
-        std::size_t used_options = 0;
-        for(const Option_p &opt : options_) {
-
-            if(opt->count() != 0) {
-                ++used_options;
-            }
-            // Required but empty
-            if(opt->get_required() && opt->count() == 0) {
-                throw RequiredError(opt->get_name());
-            }
-            // Requires
-            for(const Option *opt_req : opt->needs_)
-                if(opt->count() > 0 && opt_req->count() == 0)
-                    throw RequiresError(opt->get_name(), opt_req->get_name());
-            // Excludes
-            for(const Option *opt_ex : opt->excludes_)
-                if(opt->count() > 0 && opt_ex->count() != 0)
-                    throw ExcludesError(opt->get_name(), opt_ex->get_name());
-        }
-        // check for the required number of subcommands
-        if(require_subcommand_min_ > 0) {
-            auto selected_subcommands = get_subcommands();
-            if(require_subcommand_min_ > selected_subcommands.size())
-                throw RequiredError::Subcommand(require_subcommand_min_);
-        }
-
-        // Max error cannot occur, the extra subcommand will parse as an ExtrasError or a remaining item.
-
-        // run this loop to check how many unnamed subcommands were actually used since they are considered options
-        // from the perspective of an App
-        for(App_p &sub : subcommands_) {
-            if(sub->disabled_)
-                continue;
-            if(sub->name_.empty() && sub->count_all() > 0) {
-                ++used_options;
-            }
-        }
-
-        if(require_option_min_ > used_options || (require_option_max_ > 0 && require_option_max_ < used_options)) {
-            auto option_list = detail::join(options_, [this](const Option_p &ptr) {
-                if(ptr.get() == help_ptr_ || ptr.get() == help_all_ptr_) {
-                    return std::string{};
-                }
-                return ptr->get_name(false, true);
-            });
-
-            auto subc_list = get_subcommands([](App *app) { return ((app->get_name().empty()) && (!app->disabled_)); });
-            if(!subc_list.empty()) {
-                option_list += "," + detail::join(subc_list, [](const App *app) { return app->get_display_name(); });
-            }
-            throw RequiredError::Option(require_option_min_, require_option_max_, used_options, option_list);
-        }
-
-        // now process the requirements for subcommands if needed
-        for(App_p &sub : subcommands_) {
-            if(sub->disabled_)
-                continue;
-            if(sub->name_.empty() && sub->required_ == false) {
-                if(sub->count_all() == 0) {
-                    if(require_option_min_ > 0 && require_option_min_ <= used_options) {
-                        continue;
-                        // if we have met the requirement and there is nothing in this option group skip checking
-                        // requirements
-                    }
-                    if(require_option_max_ > 0 && used_options >= require_option_min_) {
-                        continue;
-                        // if we have met the requirement and there is nothing in this option group skip checking
-                        // requirements
-                    }
-                }
-            }
-            if(sub->count() > 0 || sub->name_.empty()) {
-                sub->_process_requirements();
-            }
-
-            if(sub->required_ && sub->count_all() == 0) {
-                throw(CLI::RequiredError(sub->get_display_name()));
-            }
-        }
-    }
+    void _process_requirements();
     /// Process callbacks and such.
-    void _process() {
-        try {
-            // the config file might generate a FileError but that should not be processed until later in the process
-            // to allow for help, version and other errors to generate first.
-            _process_config_file();
-
-            // process env shouldn't throw but no reason to process it if config generated an error
-            _process_env();
-        } catch(const CLI::FileError &) {
-            // callbacks and help_flags can generate exceptions which should take priority
-            // over the config file error if one exists.
-            _process_callbacks();
-            _process_help_flags();
-            throw;
-        }
-
-        _process_callbacks();
-        _process_help_flags();
-
-        _process_requirements();
-    }
+    void _process();
     /// Throw an error if anything is left over and should not be.
-    void _process_extras() {
-        if(!(allow_extras_ || prefix_command_)) {
-            std::size_t num_left_over = remaining_size();
-            if(num_left_over > 0) {
-                throw ExtrasError(name_, remaining(false));
-            }
-        }
-
-        for(App_p &sub : subcommands_) {
-            if(sub->count() > 0)
-                sub->_process_extras();
-        }
-    }
+    void _process_extras();
     /// Throw an error if anything is left over and should not be.
     /// Modifies the args to fill in the missing items before throwing.
-    void _process_extras(std::vector<std::string> &args) {
-        if(!(allow_extras_ || prefix_command_)) {
-            std::size_t num_left_over = remaining_size();
-            if(num_left_over > 0) {
-                args = remaining(false);
-                throw ExtrasError(name_, args);
-            }
-        }
-
-        for(App_p &sub : subcommands_) {
-            if(sub->count() > 0)
-                sub->_process_extras(args);
-        }
-    }
+    void _process_extras(std::vector<std::string> &args);
     /// Internal function to recursively increment the parsed counter on the current app as well unnamed subcommands
-    void increment_parsed() {
-        ++parsed_;
-        for(App_p &sub : subcommands_) {
-            if(sub->get_name().empty())
-                sub->increment_parsed();
-        }
-    }
-    /// Internal parse function
-    void _parse(std::vector<std::string> &args) {
-        increment_parsed();
-        _trigger_pre_parse(args.size());
-        bool positional_only = false;
-
-        while(!args.empty()) {
-            if(!_parse_single(args, positional_only)) {
-                break;
-            }
-        }
-
-        if(parent_ == nullptr) {
-            _process();
-
-            // Throw error if any items are left over (depending on settings)
-            _process_extras(args);
-
-            // Convert missing (pairs) to extras (string only) ready for processing in another app
-            args = remaining_for_passthrough(false);
-        } else if(parse_complete_callback_) {
-            _process_env();
-            _process_callbacks();
-            _process_help_flags();
-            _process_requirements();
-            run_callback(false, true);
-        }
-    }
+    void increment_parsed();
     /// Internal parse function
-    void _parse(std::vector<std::string> &&args) {
-        // this can only be called by the top level in which case parent == nullptr by definition
-        // operation is simplified
-        increment_parsed();
-        _trigger_pre_parse(args.size());
-        bool positional_only = false;
-
-        while(!args.empty()) {
-            _parse_single(args, positional_only);
-        }
-        _process();
+    void _parse(std::vector<std::string> &args);
-        // Throw error if any items are left over (depending on settings)
-        _process_extras();
-    }
+    /// Internal parse function
+    void _parse(std::vector<std::string> &&args);
     /// Internal function to parse a stream
-    void _parse_stream(std::istream &input) {
-        auto values = config_formatter_->from_config(input);
-        _parse_config(values);
-        increment_parsed();
-        _trigger_pre_parse(values.size());
-        _process();
-
-        // Throw error if any items are left over (depending on settings)
-        _process_extras();
-    }
+    void _parse_stream(std::istream &input);
     /// Parse one config param, return false if not found in any subcommand, remove if it is
     ///
     /// If this has more than one dot.separated.name, go into the subcommand matching it
     /// Returns true if it managed to find the option, if false you'll need to remove the arg manually.
-    void _parse_config(const std::vector<ConfigItem> &args) {
-        for(const ConfigItem &item : args) {
-            if(!_parse_single_config(item) && allow_config_extras_ == config_extras_mode::error)
-                throw ConfigError::Extras(item.fullname());
-        }
-    }
+    void _parse_config(const std::vector<ConfigItem> &args);
     /// Fill in a single config option
-    bool _parse_single_config(const ConfigItem &item, std::size_t level = 0) {
-        if(level < item.parents.size()) {
-            try {
-                auto *subcom = get_subcommand(item.parents.at(level));
-                auto result = subcom->_parse_single_config(item, level + 1);
-
-                return result;
-            } catch(const OptionNotFound &) {
-                return false;
-            }
-        }
-        // check for section open
-        if(item.name == "++") {
-            if(configurable_) {
-                increment_parsed();
-                _trigger_pre_parse(2);
-                if(parent_ != nullptr) {
-                    parent_->parsed_subcommands_.push_back(this);
-                }
-            }
-            return true;
-        }
-        // check for section close
-        if(item.name == "--") {
-            if(configurable_ && parse_complete_callback_) {
-                _process_callbacks();
-                _process_requirements();
-                run_callback();
-            }
-            return true;
-        }
-        Option *op = get_option_no_throw("--" + item.name);
-        if(op == nullptr) {
-            if(item.name.size() == 1) {
-                op = get_option_no_throw("-" + item.name);
-            }
-        }
-        if(op == nullptr) {
-            op = get_option_no_throw(item.name);
-        }
-        if(op == nullptr) {
-            // If the option was not present
-            if(get_allow_config_extras() == config_extras_mode::capture)
-                // Should we worry about classifying the extras properly?
-                missing_.emplace_back(detail::Classifier::NONE, item.fullname());
-            return false;
-        }
-
-        if(!op->get_configurable()) {
-            if(get_allow_config_extras() == config_extras_mode::ignore_all) {
-                return false;
-            }
-            throw ConfigError::NotConfigurable(item.fullname());
-        }
-
-        if(op->empty()) {
-
-            if(op->get_expected_min() == 0) {
-                // Flag parsing
-                auto res = config_formatter_->to_flag(item);
-                res = op->get_flag_value(item.name, res);
-
-                op->add_result(res);
-
-            } else {
-                op->add_result(item.inputs);
-                op->run_callback();
-            }
-        }
-
-        return true;
-    }
+    bool _parse_single_config(const ConfigItem &item, std::size_t level = 0);
     /// Parse "one" argument (some may eat more than one), delegate to parent if fails, add to missing if missing
     /// from main return false if the parse has failed and needs to return to parent
-    bool _parse_single(std::vector<std::string> &args, bool &positional_only) {
-        bool retval = true;
-        detail::Classifier classifier = positional_only ? detail::Classifier::NONE : _recognize(args.back());
-        switch(classifier) {
-        case detail::Classifier::POSITIONAL_MARK:
-            args.pop_back();
-            positional_only = true;
-            if((!_has_remaining_positionals()) && (parent_ != nullptr)) {
-                retval = false;
-            } else {
-                _move_to_missing(classifier, "--");
-            }
-            break;
-        case detail::Classifier::SUBCOMMAND_TERMINATOR:
-            // treat this like a positional mark if in the parent app
-            args.pop_back();
-            retval = false;
-            break;
-        case detail::Classifier::SUBCOMMAND:
-            retval = _parse_subcommand(args);
-            break;
-        case detail::Classifier::LONG:
-        case detail::Classifier::SHORT:
-        case detail::Classifier::WINDOWS_STYLE:
-            // If already parsed a subcommand, don't accept options_
-            _parse_arg(args, classifier);
-            break;
-        case detail::Classifier::NONE:
-            // Probably a positional or something for a parent (sub)command
-            retval = _parse_positional(args, false);
-            if(retval && positionals_at_end_) {
-                positional_only = true;
-            }
-            break;
-            // LCOV_EXCL_START
-        default:
-            throw HorribleError("unrecognized classifier (you should not see this!)");
-            // LCOV_EXCL_STOP
-        }
-        return retval;
-    }
+    bool _parse_single(std::vector<std::string> &args, bool &positional_only);
     /// Count the required remaining positional arguments
-    CLI11_NODISCARD std::size_t _count_remaining_positionals(bool required_only = false) const {
-        std::size_t retval = 0;
-        for(const Option_p &opt : options_) {
-            if(opt->get_positional() && (!required_only || opt->get_required())) {
-                if(opt->get_items_expected_min() > 0 &&
-                   static_cast<int>(opt->count()) < opt->get_items_expected_min()) {
-                    retval += static_cast<std::size_t>(opt->get_items_expected_min()) - opt->count();
-                }
-            }
-        }
-        return retval;
-    }
+    CLI11_NODISCARD std::size_t _count_remaining_positionals(bool required_only = false) const;
     /// Count the required remaining positional arguments
-    CLI11_NODISCARD bool _has_remaining_positionals() const {
-        for(const Option_p &opt : options_) {
-            if(opt->get_positional() && ((static_cast<int>(opt->count()) < opt->get_items_expected_min()))) {
-                return true;
-            }
-        }
-
-        return false;
-    }
+    CLI11_NODISCARD bool _has_remaining_positionals() const;
     /// Parse a positional, go up the tree to check
     /// @param haltOnSubcommand if set to true the operation will not process subcommands merely return false
     /// Return true if the positional was used false otherwise
-    bool _parse_positional(std::vector<std::string> &args, bool haltOnSubcommand) {
-
-        const std::string &positional = args.back();
-
-        if(positionals_at_end_) {
-            // deal with the case of required arguments at the end which should take precedence over other arguments
-            auto arg_rem = args.size();
-            auto remreq = _count_remaining_positionals(true);
-            if(arg_rem <= remreq) {
-                for(const Option_p &opt : options_) {
-                    if(opt->get_positional() && opt->required_) {
-                        if(static_cast<int>(opt->count()) < opt->get_items_expected_min()) {
-                            if(validate_positionals_) {
-                                std::string pos = positional;
-                                pos = opt->_validate(pos, 0);
-                                if(!pos.empty()) {
-                                    continue;
-                                }
-                            }
-
-                            parse_order_.push_back(opt.get());
-                            /// if we require a separator add it here
-                            if(opt->get_inject_separator()) {
-                                if(!opt->results().empty() && !opt->results().back().empty()) {
-                                    opt->add_result(std::string{});
-                                }
-                            }
-                            if(opt->get_trigger_on_parse() &&
-                               opt->current_option_state_ == Option::option_state::callback_run) {
-                                opt->clear();
-                            }
-                            opt->add_result(positional);
-                            if(opt->get_trigger_on_parse()) {
-                                opt->run_callback();
-                            }
-                            args.pop_back();
-                            return true;
-                        }
-                    }
-                }
-            }
-        }
-        for(const Option_p &opt : options_) {
-            // Eat options, one by one, until done
-            if(opt->get_positional() &&
-               (static_cast<int>(opt->count()) < opt->get_items_expected_min() || opt->get_allow_extra_args())) {
-                if(validate_positionals_) {
-                    std::string pos = positional;
-                    pos = opt->_validate(pos, 0);
-                    if(!pos.empty()) {
-                        continue;
-                    }
-                }
-                if(opt->get_inject_separator()) {
-                    if(!opt->results().empty() && !opt->results().back().empty()) {
-                        opt->add_result(std::string{});
-                    }
-                }
-                if(opt->get_trigger_on_parse() && opt->current_option_state_ == Option::option_state::callback_run) {
-                    opt->clear();
-                }
-                opt->add_result(positional);
-                if(opt->get_trigger_on_parse()) {
-                    opt->run_callback();
-                }
-                parse_order_.push_back(opt.get());
-                args.pop_back();
-                return true;
-            }
-        }
-
-        for(auto &subc : subcommands_) {
-            if((subc->name_.empty()) && (!subc->disabled_)) {
-                if(subc->_parse_positional(args, false)) {
-                    if(!subc->pre_parse_called_) {
-                        subc->_trigger_pre_parse(args.size());
-                    }
-                    return true;
-                }
-            }
-        }
-        // let the parent deal with it if possible
-        if(parent_ != nullptr && fallthrough_)
-            return _get_fallthrough_parent()->_parse_positional(args, static_cast<bool>(parse_complete_callback_));
-
-        /// Try to find a local subcommand that is repeated
-        auto *com = _find_subcommand(args.back(), true, false);
-        if(com != nullptr && (require_subcommand_max_ == 0 || require_subcommand_max_ > parsed_subcommands_.size())) {
-            if(haltOnSubcommand) {
-                return false;
-            }
-            args.pop_back();
-            com->_parse(args);
-            return true;
-        }
-        /// now try one last gasp at subcommands that have been executed before, go to root app and try to find a
-        /// subcommand in a broader way, if one exists let the parent deal with it
-        auto *parent_app = (parent_ != nullptr) ? _get_fallthrough_parent() : this;
-        com = parent_app->_find_subcommand(args.back(), true, false);
-        if(com != nullptr && (com->parent_->require_subcommand_max_ == 0 ||
-                              com->parent_->require_subcommand_max_ > com->parent_->parsed_subcommands_.size())) {
-            return false;
-        }
-
-        if(positionals_at_end_) {
-            throw CLI::ExtrasError(name_, args);
-        }
-        /// If this is an option group don't deal with it
-        if(parent_ != nullptr && name_.empty()) {
-            return false;
-        }
-        /// We are out of other options this goes to missing
-        _move_to_missing(detail::Classifier::NONE, positional);
-        args.pop_back();
-        if(prefix_command_) {
-            while(!args.empty()) {
-                _move_to_missing(detail::Classifier::NONE, args.back());
-                args.pop_back();
-            }
-        }
-
-        return true;
-    }
+    bool _parse_positional(std::vector<std::string> &args, bool haltOnSubcommand);
     /// Locate a subcommand by name with two conditions, should disabled subcommands be ignored, and should used
     /// subcommands be ignored
     CLI11_NODISCARD App *
-    _find_subcommand(const std::string &subc_name, bool ignore_disabled, bool ignore_used) const noexcept {
-        for(const App_p &com : subcommands_) {
-            if(com->disabled_ && ignore_disabled)
-                continue;
-            if(com->get_name().empty()) {
-                auto *subc = com->_find_subcommand(subc_name, ignore_disabled, ignore_used);
-                if(subc != nullptr) {
-                    return subc;
-                }
-            }
-            if(com->check_name(subc_name)) {
-                if((!*com) || !ignore_used)
-                    return com.get();
-            }
-        }
-        return nullptr;
-    }
+    _find_subcommand(const std::string &subc_name, bool ignore_disabled, bool ignore_used) const noexcept;
     /// Parse a subcommand, modify args and continue
     ///
     /// Unlike the others, this one will always allow fallthrough
     /// return true if the subcommand was processed false otherwise
-    bool _parse_subcommand(std::vector<std::string> &args) {
-        if(_count_remaining_positionals(/* required */ true) > 0) {
-            _parse_positional(args, false);
-            return true;
-        }
-        auto *com = _find_subcommand(args.back(), true, true);
-        if(com != nullptr) {
-            args.pop_back();
-            if(!com->silent_) {
-                parsed_subcommands_.push_back(com);
-            }
-            com->_parse(args);
-            auto *parent_app = com->parent_;
-            while(parent_app != this) {
-                parent_app->_trigger_pre_parse(args.size());
-                if(!com->silent_) {
-                    parent_app->parsed_subcommands_.push_back(com);
-                }
-                parent_app = parent_app->parent_;
-            }
-            return true;
-        }
-
-        if(parent_ == nullptr)
-            throw HorribleError("Subcommand " + args.back() + " missing");
-        return false;
-    }
+    bool _parse_subcommand(std::vector<std::string> &args);
     /// Parse a short (false) or long (true) argument, must be at the top of the list
     /// return true if the argument was processed or false if nothing was done
-    bool _parse_arg(std::vector<std::string> &args, detail::Classifier current_type) {
-
-        std::string current = args.back();
-
-        std::string arg_name;
-        std::string value;
-        std::string rest;
-
-        switch(current_type) {
-        case detail::Classifier::LONG:
-            if(!detail::split_long(current, arg_name, value))
-                throw HorribleError("Long parsed but missing (you should not see this):" + args.back());
-            break;
-        case detail::Classifier::SHORT:
-            if(!detail::split_short(current, arg_name, rest))
-                throw HorribleError("Short parsed but missing! You should not see this");
-            break;
-        case detail::Classifier::WINDOWS_STYLE:
-            if(!detail::split_windows_style(current, arg_name, value))
-                throw HorribleError("windows option parsed but missing! You should not see this");
-            break;
-        case detail::Classifier::SUBCOMMAND:
-        case detail::Classifier::SUBCOMMAND_TERMINATOR:
-        case detail::Classifier::POSITIONAL_MARK:
-        case detail::Classifier::NONE:
-        default:
-            throw HorribleError("parsing got called with invalid option! You should not see this");
-        }
-
-        auto op_ptr =
-            std::find_if(std::begin(options_), std::end(options_), [arg_name, current_type](const Option_p &opt) {
-                if(current_type == detail::Classifier::LONG)
-                    return opt->check_lname(arg_name);
-                if(current_type == detail::Classifier::SHORT)
-                    return opt->check_sname(arg_name);
-                // this will only get called for detail::Classifier::WINDOWS_STYLE
-                return opt->check_lname(arg_name) || opt->check_sname(arg_name);
-            });
-
-        // Option not found
-        if(op_ptr == std::end(options_)) {
-            for(auto &subc : subcommands_) {
-                if(subc->name_.empty() && !subc->disabled_) {
-                    if(subc->_parse_arg(args, current_type)) {
-                        if(!subc->pre_parse_called_) {
-                            subc->_trigger_pre_parse(args.size());
-                        }
-                        return true;
-                    }
-                }
-            }
-
-            // don't capture missing if this is a nameless subcommand and nameless subcommands can't fallthrough
-            if(parent_ != nullptr && name_.empty()) {
-                return false;
-            }
-
-            // If a subcommand, try the main command
-            if(parent_ != nullptr && fallthrough_)
-                return _get_fallthrough_parent()->_parse_arg(args, current_type);
-
-            // Otherwise, add to missing
-            args.pop_back();
-            _move_to_missing(current_type, current);
-            return true;
-        }
-
-        args.pop_back();
-
-        // Get a reference to the pointer to make syntax bearable
-        Option_p &op = *op_ptr;
-        /// if we require a separator add it here
-        if(op->get_inject_separator()) {
-            if(!op->results().empty() && !op->results().back().empty()) {
-                op->add_result(std::string{});
-            }
-        }
-        if(op->get_trigger_on_parse() && op->current_option_state_ == Option::option_state::callback_run) {
-            op->clear();
-        }
-        int min_num = (std::min)(op->get_type_size_min(), op->get_items_expected_min());
-        int max_num = op->get_items_expected_max();
-        // check container like options to limit the argument size to a single type if the allow_extra_flags argument is
-        // set. 16 is somewhat arbitrary (needs to be at least 4)
-        if(max_num >= detail::expected_max_vector_size / 16 && !op->get_allow_extra_args()) {
-            auto tmax = op->get_type_size_max();
-            max_num = detail::checked_multiply(tmax, op->get_expected_min()) ? tmax : detail::expected_max_vector_size;
-        }
-        // Make sure we always eat the minimum for unlimited vectors
-        int collected = 0;     // total number of arguments collected
-        int result_count = 0;  // local variable for number of results in a single arg string
-        // deal with purely flag like things
-        if(max_num == 0) {
-            auto res = op->get_flag_value(arg_name, value);
-            op->add_result(res);
-            parse_order_.push_back(op.get());
-        } else if(!value.empty()) {  // --this=value
-            op->add_result(value, result_count);
-            parse_order_.push_back(op.get());
-            collected += result_count;
-            // -Trest
-        } else if(!rest.empty()) {
-            op->add_result(rest, result_count);
-            parse_order_.push_back(op.get());
-            rest = "";
-            collected += result_count;
-        }
-
-        // gather the minimum number of arguments
-        while(min_num > collected && !args.empty()) {
-            std::string current_ = args.back();
-            args.pop_back();
-            op->add_result(current_, result_count);
-            parse_order_.push_back(op.get());
-            collected += result_count;
-        }
-
-        if(min_num > collected) {  // if we have run out of arguments and the minimum was not met
-            throw ArgumentMismatch::TypedAtLeast(op->get_name(), min_num, op->get_type_name());
-        }
-
-        // now check for optional arguments
-        if(max_num > collected || op->get_allow_extra_args()) {  // we allow optional arguments
-            auto remreqpos = _count_remaining_positionals(true);
-            // we have met the minimum now optionally check up to the maximum
-            while((collected < max_num || op->get_allow_extra_args()) && !args.empty() &&
-                  _recognize(args.back(), false) == detail::Classifier::NONE) {
-                // If any required positionals remain, don't keep eating
-                if(remreqpos >= args.size()) {
-                    break;
-                }
-                if(validate_optional_arguments_) {
-                    std::string arg = args.back();
-                    arg = op->_validate(arg, 0);
-                    if(!arg.empty()) {
-                        break;
-                    }
-                }
-                op->add_result(args.back(), result_count);
-                parse_order_.push_back(op.get());
-                args.pop_back();
-                collected += result_count;
-            }
-
-            // Allow -- to end an unlimited list and "eat" it
-            if(!args.empty() && _recognize(args.back()) == detail::Classifier::POSITIONAL_MARK)
-                args.pop_back();
-            // optional flag that didn't receive anything now get the default value
-            if(min_num == 0 && max_num > 0 && collected == 0) {
-                auto res = op->get_flag_value(arg_name, std::string{});
-                op->add_result(res);
-                parse_order_.push_back(op.get());
-            }
-        }
-        // if we only partially completed a type then add an empty string if allowed for later processing
-        if(min_num > 0 && (collected % op->get_type_size_max()) != 0) {
-            if(op->get_type_size_max() != op->get_type_size_min()) {
-                op->add_result(std::string{});
-            } else {
-                throw ArgumentMismatch::PartialType(op->get_name(), op->get_type_size_min(), op->get_type_name());
-            }
-        }
-        if(op->get_trigger_on_parse()) {
-            op->run_callback();
-        }
-        if(!rest.empty()) {
-            rest = "-" + rest;
-            args.push_back(rest);
-        }
-        return true;
-    }
+    bool _parse_arg(std::vector<std::string> &args, detail::Classifier current_type);
     /// Trigger the pre_parse callback if needed
-    void _trigger_pre_parse(std::size_t remaining_args) {
-        if(!pre_parse_called_) {
-            pre_parse_called_ = true;
-            if(pre_parse_callback_) {
-                pre_parse_callback_(remaining_args);
-            }
-        } else if(immediate_callback_) {
-            if(!name_.empty()) {
-                auto pcnt = parsed_;
-                auto extras = std::move(missing_);
-                clear();
-                parsed_ = pcnt;
-                pre_parse_called_ = true;
-                missing_ = std::move(extras);
-            }
-        }
-    }
+    void _trigger_pre_parse(std::size_t remaining_args);
     /// Get the appropriate parent to fallthrough to which is the first one that has a name or the main app
-    App *_get_fallthrough_parent() {
-        if(parent_ == nullptr) {
-            throw(HorribleError("No Valid parent"));
-        }
-        auto *fallthrough_parent = parent_;
-        while((fallthrough_parent->parent_ != nullptr) && (fallthrough_parent->get_name().empty())) {
-            fallthrough_parent = fallthrough_parent->parent_;
-        }
-        return fallthrough_parent;
-    }
+    App *_get_fallthrough_parent();
     /// Helper function to run through all possible comparisons of subcommand names to check there is no overlap
-    CLI11_NODISCARD const std::string &_compare_subcommand_names(const App &subcom, const App &base) const {
-        static const std::string estring;
-        if(subcom.disabled_) {
-            return estring;
-        }
-        for(const auto &subc : base.subcommands_) {
-            if(subc.get() != &subcom) {
-                if(subc->disabled_) {
-                    continue;
-                }
-                if(!subcom.get_name().empty()) {
-                    if(subc->check_name(subcom.get_name())) {
-                        return subcom.get_name();
-                    }
-                }
-                if(!subc->get_name().empty()) {
-                    if(subcom.check_name(subc->get_name())) {
-                        return subc->get_name();
-                    }
-                }
-                for(const auto &les : subcom.aliases_) {
-                    if(subc->check_name(les)) {
-                        return les;
-                    }
-                }
-                // this loop is needed in case of ignore_underscore or ignore_case on one but not the other
-                for(const auto &les : subc->aliases_) {
-                    if(subcom.check_name(les)) {
-                        return les;
-                    }
-                }
-                // if the subcommand is an option group we need to check deeper
-                if(subc->get_name().empty()) {
-                    const auto &cmpres = _compare_subcommand_names(subcom, *subc);
-                    if(!cmpres.empty()) {
-                        return cmpres;
-                    }
-                }
-                // if the test subcommand is an option group we need to check deeper
-                if(subcom.get_name().empty()) {
-                    const auto &cmpres = _compare_subcommand_names(*subc, subcom);
-                    if(!cmpres.empty()) {
-                        return cmpres;
-                    }
-                }
-            }
-        }
-        return estring;
-    }
+    CLI11_NODISCARD const std::string &_compare_subcommand_names(const App &subcom, const App &base) const;
+
     /// Helper function to place extra values in the most appropriate position
-    void _move_to_missing(detail::Classifier val_type, const std::string &val) {
-        if(allow_extras_ || subcommands_.empty()) {
-            missing_.emplace_back(val_type, val);
-            return;
-        }
-        // allow extra arguments to be places in an option group if it is allowed there
-        for(auto &subc : subcommands_) {
-            if(subc->name_.empty() && subc->allow_extras_) {
-                subc->missing_.emplace_back(val_type, val);
-                return;
-            }
-        }
-        // if we haven't found any place to put them yet put them in missing
-        missing_.emplace_back(val_type, val);
-    }
+    void _move_to_missing(detail::Classifier val_type, const std::string &val);
   public:
     /// function that could be used by subclasses of App to shift options around into subcommands
-    void _move_option(Option *opt, App *app) {
-        if(opt == nullptr) {
-            throw OptionNotFound("the option is NULL");
-        }
-        // verify that the give app is actually a subcommand
-        bool found = false;
-        for(auto &subc : subcommands_) {
-            if(app == subc.get()) {
-                found = true;
-            }
-        }
-        if(!found) {
-            throw OptionNotFound("The Given app is not a subcommand");
-        }
-
-        if((help_ptr_ == opt) || (help_all_ptr_ == opt))
-            throw OptionAlreadyAdded("cannot move help options");
-
-        if(config_ptr_ == opt)
-            throw OptionAlreadyAdded("cannot move config file options");
-
-        auto iterator =
-            std::find_if(std::begin(options_), std::end(options_), [opt](const Option_p &v) { return v.get() == opt; });
-        if(iterator != std::end(options_)) {
-            const auto &opt_p = *iterator;
-            if(std::find_if(std::begin(app->options_), std::end(app->options_), [&opt_p](const Option_p &v) {
-                   return (*v == *opt_p);
-               }) == std::end(app->options_)) {
-                // only erase after the insertion was successful
-                app->options_.push_back(std::move(*iterator));
-                options_.erase(iterator);
-            } else {
-                throw OptionAlreadyAdded("option was not located: " + opt->get_name());
-            }
-        } else {
-            throw OptionNotFound("could not locate the given Option");
-        }
-    }
+    void _move_option(Option *opt, App *app);
 };  // namespace CLI
 /// Extension of App to better manage groups of options
@@ -3063,62 +1312,21 @@ class Option_group : public App {
         return subcom;
     }
 };
-/// Helper function to enable one option group/subcommand when another is used
-inline void TriggerOn(App *trigger_app, App *app_to_enable) {
-    app_to_enable->enabled_by_default(false);
-    app_to_enable->disabled_by_default();
-    trigger_app->preparse_callback([app_to_enable](std::size_t) { app_to_enable->disabled(false); });
-}
 /// Helper function to enable one option group/subcommand when another is used
-inline void TriggerOn(App *trigger_app, std::vector<App *> apps_to_enable) {
-    for(auto &app : apps_to_enable) {
-        app->enabled_by_default(false);
-        app->disabled_by_default();
-    }
+CLI11_INLINE void TriggerOn(App *trigger_app, App *app_to_enable);
-    trigger_app->preparse_callback([apps_to_enable](std::size_t) {
-        for(const auto &app : apps_to_enable) {
-            app->disabled(false);
-        }
-    });
-}
+/// Helper function to enable one option group/subcommand when another is used
+CLI11_INLINE void TriggerOn(App *trigger_app, std::vector<App *> apps_to_enable);
 /// Helper function to disable one option group/subcommand when another is used
-inline void TriggerOff(App *trigger_app, App *app_to_enable) {
-    app_to_enable->disabled_by_default(false);
-    app_to_enable->enabled_by_default();
-    trigger_app->preparse_callback([app_to_enable](std::size_t) { app_to_enable->disabled(); });
-}
+CLI11_INLINE void TriggerOff(App *trigger_app, App *app_to_enable);
 /// Helper function to disable one option group/subcommand when another is used
-inline void TriggerOff(App *trigger_app, std::vector<App *> apps_to_enable) {
-    for(auto &app : apps_to_enable) {
-        app->disabled_by_default(false);
-        app->enabled_by_default();
-    }
-
-    trigger_app->preparse_callback([apps_to_enable](std::size_t) {
-        for(const auto &app : apps_to_enable) {
-            app->disabled();
-        }
-    });
-}
+CLI11_INLINE void TriggerOff(App *trigger_app, std::vector<App *> apps_to_enable);
 /// Helper function to mark an option as deprecated
-inline void deprecate_option(Option *opt, const std::string &replacement = "") {
-    Validator deprecate_warning{[opt, replacement](std::string &) {
-                                    std::cout << opt->get_name() << " is deprecated please use '" << replacement
-                                              << "' instead\n";
-                                    return std::string();
-                                },
-                                "DEPRECATED"};
-    deprecate_warning.application_index(0);
-    opt->check(deprecate_warning);
-    if(!replacement.empty()) {
-        opt->description(opt->get_description() + " DEPRECATED: please use '" + replacement + "' instead");
-    }
-}
+CLI11_INLINE void deprecate_option(Option *opt, const std::string &replacement = "");
 /// Helper function to mark an option as deprecated
 inline void deprecate_option(App *app, const std::string &option_name, const std::string &replacement = "") {
@@ -3133,84 +1341,24 @@ inline void deprecate_option(App &amp;app, const std::string &amp;option_name, const std
 }
 /// Helper function to mark an option as retired
-inline void retire_option(App *app, Option *opt) {
-    App temp;
-    auto *option_copy = temp.add_option(opt->get_name(false, true))
-                            ->type_size(opt->get_type_size_min(), opt->get_type_size_max())
-                            ->expected(opt->get_expected_min(), opt->get_expected_max())
-                            ->allow_extra_args(opt->get_allow_extra_args());
-
-    app->remove_option(opt);
-    auto *opt2 = app->add_option(option_copy->get_name(false, true), "option has been retired and has no effect")
-                     ->type_name("RETIRED")
-                     ->default_str("RETIRED")
-                     ->type_size(option_copy->get_type_size_min(), option_copy->get_type_size_max())
-                     ->expected(option_copy->get_expected_min(), option_copy->get_expected_max())
-                     ->allow_extra_args(option_copy->get_allow_extra_args());
-
-    Validator retired_warning{[opt2](std::string &) {
-                                  std::cout << "WARNING " << opt2->get_name() << " is retired and has no effect\n";
-                                  return std::string();
-                              },
-                              ""};
-    retired_warning.application_index(0);
-    opt2->check(retired_warning);
-}
+CLI11_INLINE void retire_option(App *app, Option *opt);
 /// Helper function to mark an option as retired
-inline void retire_option(App &app, Option *opt) { retire_option(&app, opt); }
+CLI11_INLINE void retire_option(App &app, Option *opt);
 /// Helper function to mark an option as retired
-inline void retire_option(App *app, const std::string &option_name) {
-
-    auto *opt = app->get_option_no_throw(option_name);
-    if(opt != nullptr) {
-        retire_option(app, opt);
-        return;
-    }
-    auto *opt2 = app->add_option(option_name, "option has been retired and has no effect")
-                     ->type_name("RETIRED")
-                     ->expected(0, 1)
-                     ->default_str("RETIRED");
-    Validator retired_warning{[opt2](std::string &) {
-                                  std::cout << "WARNING " << opt2->get_name() << " is retired and has no effect\n";
-                                  return std::string();
-                              },
-                              ""};
-    retired_warning.application_index(0);
-    opt2->check(retired_warning);
-}
+CLI11_INLINE void retire_option(App *app, const std::string &option_name);
 /// Helper function to mark an option as retired
-inline void retire_option(App &app, const std::string &option_name) { retire_option(&app, option_name); }
+CLI11_INLINE void retire_option(App &app, const std::string &option_name);
 namespace FailureMessage {
 /// Printout a clean, simple message on error (the default in CLI11 1.5+)
-inline std::string simple(const App *app, const Error &e) {
-    std::string header = std::string(e.what()) + "\n";
-    std::vector<std::string> names;
-
-    // Collect names
-    if(app->get_help_ptr() != nullptr)
-        names.push_back(app->get_help_ptr()->get_name());
-
-    if(app->get_help_all_ptr() != nullptr)
-        names.push_back(app->get_help_all_ptr()->get_name());
-
-    // If any names found, suggest those
-    if(!names.empty())
-        header += "Run with " + detail::join(names, " or ") + " for more information.\n";
-
-    return header;
-}
+CLI11_INLINE std::string simple(const App *app, const Error &e);
 /// Printout the full help string on error (if this fn is set, the old default for CLI11)
-inline std::string help(const App *app, const Error &e) {
-    std::string header = std::string("ERROR: ") + e.get_name() + ": " + e.what() + "\n";
-    header += app->help();
-    return header;
-}
+CLI11_INLINE std::string help(const App *app, const Error &e);
 }  // namespace FailureMessage
@@ -3250,3 +1398,7 @@ struct AppFriend {
 // [CLI11:app_hpp:end]
 }  // namespace CLI
+
+#ifndef CLI11_COMPILE
+#include "impl/App_inl.hpp"
+#endif
@@ -65,4 +65,11 @@
 #define CLI11_USE_STATIC_RTTI 1
 #endif
 #endif
+
+/** Inline macro **/
+#ifdef CLI11_COMPILE
+#define CLI11_INLINE
+#else
+#define CLI11_INLINE inline
+#endif
 // [CLI11:macros_hpp:end]
+// Copyright (c) 2017-2022, University of Cincinnati, developed by Henry Schreiner
+// under NSF AWARD 1414736 and by the respective contributors.
+// All rights reserved.
+//
+// SPDX-License-Identifier: BSD-3-Clause
+
+#pragma once
+
+// This include is only needed for IDEs to discover symbols
+#include <CLI/App.hpp>
+
+// [CLI11:public_includes:set]
+#include <algorithm>
+#include <memory>
+#include <string>
+#include <utility>
+#include <vector>
+// [CLI11:public_includes:end]
+
+namespace CLI {
+// [CLI11:app_inl_hpp:verbatim]
+
+CLI11_INLINE App::App(std::string app_description, std::string app_name, App *parent)
+    : name_(std::move(app_name)), description_(std::move(app_description)), parent_(parent) {
+    // Inherit if not from a nullptr
+    if(parent_ != nullptr) {
+        if(parent_->help_ptr_ != nullptr)
+            set_help_flag(parent_->help_ptr_->get_name(false, true), parent_->help_ptr_->get_description());
+        if(parent_->help_all_ptr_ != nullptr)
+            set_help_all_flag(parent_->help_all_ptr_->get_name(false, true), parent_->help_all_ptr_->get_description());
+
+        /// OptionDefaults
+        option_defaults_ = parent_->option_defaults_;
+
+        // INHERITABLE
+        failure_message_ = parent_->failure_message_;
+        allow_extras_ = parent_->allow_extras_;
+        allow_config_extras_ = parent_->allow_config_extras_;
+        prefix_command_ = parent_->prefix_command_;
+        immediate_callback_ = parent_->immediate_callback_;
+        ignore_case_ = parent_->ignore_case_;
+        ignore_underscore_ = parent_->ignore_underscore_;
+        fallthrough_ = parent_->fallthrough_;
+        validate_positionals_ = parent_->validate_positionals_;
+        validate_optional_arguments_ = parent_->validate_optional_arguments_;
+        configurable_ = parent_->configurable_;
+        allow_windows_style_options_ = parent_->allow_windows_style_options_;
+        group_ = parent_->group_;
+        footer_ = parent_->footer_;
+        formatter_ = parent_->formatter_;
+        config_formatter_ = parent_->config_formatter_;
+        require_subcommand_max_ = parent_->require_subcommand_max_;
+    }
+}
+
+CLI11_INLINE App *App::name(std::string app_name) {
+
+    if(parent_ != nullptr) {
+        auto oname = name_;
+        name_ = app_name;
+        const auto &res = _compare_subcommand_names(*this, *_get_fallthrough_parent());
+        if(!res.empty()) {
+            name_ = oname;
+            throw(OptionAlreadyAdded(app_name + " conflicts with existing subcommand names"));
+        }
+    } else {
+        name_ = app_name;
+    }
+    has_automatic_name_ = false;
+    return this;
+}
+
+CLI11_INLINE App *App::alias(std::string app_name) {
+    if(app_name.empty() || !detail::valid_alias_name_string(app_name)) {
+        throw IncorrectConstruction("Aliases may not be empty or contain newlines or null characters");
+    }
+    if(parent_ != nullptr) {
+        aliases_.push_back(app_name);
+        const auto &res = _compare_subcommand_names(*this, *_get_fallthrough_parent());
+        if(!res.empty()) {
+            aliases_.pop_back();
+            throw(OptionAlreadyAdded("alias already matches an existing subcommand: " + app_name));
+        }
+    } else {
+        aliases_.push_back(app_name);
+    }
+
+    return this;
+}
+
+CLI11_INLINE App *App::immediate_callback(bool immediate) {
+    immediate_callback_ = immediate;
+    if(immediate_callback_) {
+        if(final_callback_ && !(parse_complete_callback_)) {
+            std::swap(final_callback_, parse_complete_callback_);
+        }
+    } else if(!(final_callback_) && parse_complete_callback_) {
+        std::swap(final_callback_, parse_complete_callback_);
+    }
+    return this;
+}
+
+CLI11_INLINE App *App::ignore_case(bool value) {
+    if(value && !ignore_case_) {
+        ignore_case_ = true;
+        auto *p = (parent_ != nullptr) ? _get_fallthrough_parent() : this;
+        const auto &match = _compare_subcommand_names(*this, *p);
+        if(!match.empty()) {
+            ignore_case_ = false;  // we are throwing so need to be exception invariant
+            throw OptionAlreadyAdded("ignore case would cause subcommand name conflicts: " + match);
+        }
+    }
+    ignore_case_ = value;
+    return this;
+}
+
+CLI11_INLINE App *App::ignore_underscore(bool value) {
+    if(value && !ignore_underscore_) {
+        ignore_underscore_ = true;
+        auto *p = (parent_ != nullptr) ? _get_fallthrough_parent() : this;
+        const auto &match = _compare_subcommand_names(*this, *p);
+        if(!match.empty()) {
+            ignore_underscore_ = false;
+            throw OptionAlreadyAdded("ignore underscore would cause subcommand name conflicts: " + match);
+        }
+    }
+    ignore_underscore_ = value;
+    return this;
+}
+
+CLI11_INLINE Option *App::add_option(std::string option_name,
+                                     callback_t option_callback,
+                                     std::string option_description,
+                                     bool defaulted,
+                                     std::function<std::string()> func) {
+    Option myopt{option_name, option_description, option_callback, this};
+
+    if(std::find_if(std::begin(options_), std::end(options_), [&myopt](const Option_p &v) { return *v == myopt; }) ==
+       std::end(options_)) {
+        options_.emplace_back();
+        Option_p &option = options_.back();
+        option.reset(new Option(option_name, option_description, option_callback, this));
+
+        // Set the default string capture function
+        option->default_function(func);
+
+        // For compatibility with CLI11 1.7 and before, capture the default string here
+        if(defaulted)
+            option->capture_default_str();
+
+        // Transfer defaults to the new option
+        option_defaults_.copy_to(option.get());
+
+        // Don't bother to capture if we already did
+        if(!defaulted && option->get_always_capture_default())
+            option->capture_default_str();
+
+        return option.get();
+    }
+    // we know something matches now find what it is so we can produce more error information
+    for(auto &opt : options_) {
+        const auto &matchname = opt->matching_name(myopt);
+        if(!matchname.empty()) {
+            throw(OptionAlreadyAdded("added option matched existing option name: " + matchname));
+        }
+    }
+    // this line should not be reached the above loop should trigger the throw
+    throw(OptionAlreadyAdded("added option matched existing option name"));  // LCOV_EXCL_LINE
+}
+
+CLI11_INLINE Option *App::set_help_flag(std::string flag_name, const std::string &help_description) {
+    // take flag_description by const reference otherwise add_flag tries to assign to help_description
+    if(help_ptr_ != nullptr) {
+        remove_option(help_ptr_);
+        help_ptr_ = nullptr;
+    }
+
+    // Empty name will simply remove the help flag
+    if(!flag_name.empty()) {
+        help_ptr_ = add_flag(flag_name, help_description);
+        help_ptr_->configurable(false);
+    }
+
+    return help_ptr_;
+}
+
+CLI11_INLINE Option *App::set_help_all_flag(std::string help_name, const std::string &help_description) {
+    // take flag_description by const reference otherwise add_flag tries to assign to flag_description
+    if(help_all_ptr_ != nullptr) {
+        remove_option(help_all_ptr_);
+        help_all_ptr_ = nullptr;
+    }
+
+    // Empty name will simply remove the help all flag
+    if(!help_name.empty()) {
+        help_all_ptr_ = add_flag(help_name, help_description);
+        help_all_ptr_->configurable(false);
+    }
+
+    return help_all_ptr_;
+}
+
+CLI11_INLINE Option *
+App::set_version_flag(std::string flag_name, const std::string &versionString, const std::string &version_help) {
+    // take flag_description by const reference otherwise add_flag tries to assign to version_description
+    if(version_ptr_ != nullptr) {
+        remove_option(version_ptr_);
+        version_ptr_ = nullptr;
+    }
+
+    // Empty name will simply remove the version flag
+    if(!flag_name.empty()) {
+        version_ptr_ = add_flag_callback(
+            flag_name, [versionString]() { throw(CLI::CallForVersion(versionString, 0)); }, version_help);
+        version_ptr_->configurable(false);
+    }
+
+    return version_ptr_;
+}
+
+CLI11_INLINE Option *
+App::set_version_flag(std::string flag_name, std::function<std::string()> vfunc, const std::string &version_help) {
+    if(version_ptr_ != nullptr) {
+        remove_option(version_ptr_);
+        version_ptr_ = nullptr;
+    }
+
+    // Empty name will simply remove the version flag
+    if(!flag_name.empty()) {
+        version_ptr_ = add_flag_callback(
+            flag_name, [vfunc]() { throw(CLI::CallForVersion(vfunc(), 0)); }, version_help);
+        version_ptr_->configurable(false);
+    }
+
+    return version_ptr_;
+}
+
+CLI11_INLINE Option *App::_add_flag_internal(std::string flag_name, CLI::callback_t fun, std::string flag_description) {
+    Option *opt = nullptr;
+    if(detail::has_default_flag_values(flag_name)) {
+        // check for default values and if it has them
+        auto flag_defaults = detail::get_default_flag_values(flag_name);
+        detail::remove_default_flag_values(flag_name);
+        opt = add_option(std::move(flag_name), std::move(fun), std::move(flag_description), false);
+        for(const auto &fname : flag_defaults)
+            opt->fnames_.push_back(fname.first);
+        opt->default_flag_values_ = std::move(flag_defaults);
+    } else {
+        opt = add_option(std::move(flag_name), std::move(fun), std::move(flag_description), false);
+    }
+    // flags cannot have positional values
+    if(opt->get_positional()) {
+        auto pos_name = opt->get_name(true);
+        remove_option(opt);
+        throw IncorrectConstruction::PositionalFlag(pos_name);
+    }
+    opt->multi_option_policy(MultiOptionPolicy::TakeLast);
+    opt->expected(0);
+    opt->required(false);
+    return opt;
+}
+
+CLI11_INLINE Option *App::add_flag_callback(std::string flag_name,
+                                            std::function<void(void)> function,  ///< A function to call, void(void)
+                                            std::string flag_description) {
+
+    CLI::callback_t fun = [function](const CLI::results_t &res) {
+        bool trigger{false};
+        auto result = CLI::detail::lexical_cast(res[0], trigger);
+        if(result && trigger) {
+            function();
+        }
+        return result;
+    };
+    return _add_flag_internal(flag_name, std::move(fun), std::move(flag_description));
+}
+
+CLI11_INLINE Option *
+App::add_flag_function(std::string flag_name,
+                       std::function<void(std::int64_t)> function,  ///< A function to call, void(int)
+                       std::string flag_description) {
+
+    CLI::callback_t fun = [function](const CLI::results_t &res) {
+        std::int64_t flag_count{0};
+        CLI::detail::lexical_cast(res[0], flag_count);
+        function(flag_count);
+        return true;
+    };
+    return _add_flag_internal(flag_name, std::move(fun), std::move(flag_description))
+        ->multi_option_policy(MultiOptionPolicy::Sum);
+}
+
+CLI11_INLINE Option *App::set_config(std::string option_name,
+                                     std::string default_filename,
+                                     const std::string &help_message,
+                                     bool config_required) {
+
+    // Remove existing config if present
+    if(config_ptr_ != nullptr) {
+        remove_option(config_ptr_);
+        config_ptr_ = nullptr;  // need to remove the config_ptr completely
+    }
+
+    // Only add config if option passed
+    if(!option_name.empty()) {
+        config_ptr_ = add_option(option_name, help_message);
+        if(config_required) {
+            config_ptr_->required();
+        }
+        if(!default_filename.empty()) {
+            config_ptr_->default_str(std::move(default_filename));
+        }
+        config_ptr_->configurable(false);
+    }
+
+    return config_ptr_;
+}
+
+CLI11_INLINE bool App::remove_option(Option *opt) {
+    // Make sure no links exist
+    for(Option_p &op : options_) {
+        op->remove_needs(opt);
+        op->remove_excludes(opt);
+    }
+
+    if(help_ptr_ == opt)
+        help_ptr_ = nullptr;
+    if(help_all_ptr_ == opt)
+        help_all_ptr_ = nullptr;
+
+    auto iterator =
+        std::find_if(std::begin(options_), std::end(options_), [opt](const Option_p &v) { return v.get() == opt; });
+    if(iterator != std::end(options_)) {
+        options_.erase(iterator);
+        return true;
+    }
+    return false;
+}
+
+CLI11_INLINE App *App::add_subcommand(std::string subcommand_name, std::string subcommand_description) {
+    if(!subcommand_name.empty() && !detail::valid_name_string(subcommand_name)) {
+        if(!detail::valid_first_char(subcommand_name[0])) {
+            throw IncorrectConstruction("Subcommand name starts with invalid character, '!' and '-' are not allowed");
+        }
+        for(auto c : subcommand_name) {
+            if(!detail::valid_later_char(c)) {
+                throw IncorrectConstruction(std::string("Subcommand name contains invalid character ('") + c +
+                                            "'), all characters are allowed except"
+                                            "'=',':','{','}', and ' '");
+            }
+        }
+    }
+    CLI::App_p subcom = std::shared_ptr<App>(new App(std::move(subcommand_description), subcommand_name, this));
+    return add_subcommand(std::move(subcom));
+}
+
+CLI11_INLINE App *App::add_subcommand(CLI::App_p subcom) {
+    if(!subcom)
+        throw IncorrectConstruction("passed App is not valid");
+    auto *ckapp = (name_.empty() && parent_ != nullptr) ? _get_fallthrough_parent() : this;
+    const auto &mstrg = _compare_subcommand_names(*subcom, *ckapp);
+    if(!mstrg.empty()) {
+        throw(OptionAlreadyAdded("subcommand name or alias matches existing subcommand: " + mstrg));
+    }
+    subcom->parent_ = this;
+    subcommands_.push_back(std::move(subcom));
+    return subcommands_.back().get();
+}
+
+CLI11_INLINE bool App::remove_subcommand(App *subcom) {
+    // Make sure no links exist
+    for(App_p &sub : subcommands_) {
+        sub->remove_excludes(subcom);
+        sub->remove_needs(subcom);
+    }
+
+    auto iterator = std::find_if(
+        std::begin(subcommands_), std::end(subcommands_), [subcom](const App_p &v) { return v.get() == subcom; });
+    if(iterator != std::end(subcommands_)) {
+        subcommands_.erase(iterator);
+        return true;
+    }
+    return false;
+}
+
+CLI11_INLINE App *App::get_subcommand(const App *subcom) const {
+    if(subcom == nullptr)
+        throw OptionNotFound("nullptr passed");
+    for(const App_p &subcomptr : subcommands_)
+        if(subcomptr.get() == subcom)
+            return subcomptr.get();
+    throw OptionNotFound(subcom->get_name());
+}
+
+CLI11_NODISCARD CLI11_INLINE App *App::get_subcommand(std::string subcom) const {
+    auto *subc = _find_subcommand(subcom, false, false);
+    if(subc == nullptr)
+        throw OptionNotFound(subcom);
+    return subc;
+}
+
+CLI11_NODISCARD CLI11_INLINE App *App::get_subcommand(int index) const {
+    if(index >= 0) {
+        auto uindex = static_cast<unsigned>(index);
+        if(uindex < subcommands_.size())
+            return subcommands_[uindex].get();
+    }
+    throw OptionNotFound(std::to_string(index));
+}
+
+CLI11_INLINE CLI::App_p App::get_subcommand_ptr(App *subcom) const {
+    if(subcom == nullptr)
+        throw OptionNotFound("nullptr passed");
+    for(const App_p &subcomptr : subcommands_)
+        if(subcomptr.get() == subcom)
+            return subcomptr;
+    throw OptionNotFound(subcom->get_name());
+}
+
+CLI11_NODISCARD CLI11_INLINE CLI::App_p App::get_subcommand_ptr(std::string subcom) const {
+    for(const App_p &subcomptr : subcommands_)
+        if(subcomptr->check_name(subcom))
+            return subcomptr;
+    throw OptionNotFound(subcom);
+}
+
+CLI11_NODISCARD CLI11_INLINE CLI::App_p App::get_subcommand_ptr(int index) const {
+    if(index >= 0) {
+        auto uindex = static_cast<unsigned>(index);
+        if(uindex < subcommands_.size())
+            return subcommands_[uindex];
+    }
+    throw OptionNotFound(std::to_string(index));
+}
+
+CLI11_NODISCARD CLI11_INLINE std::size_t App::count_all() const {
+    std::size_t cnt{0};
+    for(const auto &opt : options_) {
+        cnt += opt->count();
+    }
+    for(const auto &sub : subcommands_) {
+        cnt += sub->count_all();
+    }
+    if(!get_name().empty()) {  // for named subcommands add the number of times the subcommand was called
+        cnt += parsed_;
+    }
+    return cnt;
+}
+
+CLI11_INLINE void App::clear() {
+
+    parsed_ = 0;
+    pre_parse_called_ = false;
+
+    missing_.clear();
+    parsed_subcommands_.clear();
+    for(const Option_p &opt : options_) {
+        opt->clear();
+    }
+    for(const App_p &subc : subcommands_) {
+        subc->clear();
+    }
+}
+
+CLI11_INLINE void App::parse(int argc, const char *const *argv) {
+    // If the name is not set, read from command line
+    if(name_.empty() || has_automatic_name_) {
+        has_automatic_name_ = true;
+        name_ = argv[0];
+    }
+
+    std::vector<std::string> args;
+    args.reserve(static_cast<std::size_t>(argc) - 1U);
+    for(auto i = static_cast<std::size_t>(argc) - 1U; i > 0U; --i)
+        args.emplace_back(argv[i]);
+    parse(std::move(args));
+}
+
+CLI11_INLINE void App::parse(std::string commandline, bool program_name_included) {
+
+    if(program_name_included) {
+        auto nstr = detail::split_program_name(commandline);
+        if((name_.empty()) || (has_automatic_name_)) {
+            has_automatic_name_ = true;
+            name_ = nstr.first;
+        }
+        commandline = std::move(nstr.second);
+    } else {
+        detail::trim(commandline);
+    }
+    // the next section of code is to deal with quoted arguments after an '=' or ':' for windows like operations
+    if(!commandline.empty()) {
+        commandline = detail::find_and_modify(commandline, "=", detail::escape_detect);
+        if(allow_windows_style_options_)
+            commandline = detail::find_and_modify(commandline, ":", detail::escape_detect);
+    }
+
+    auto args = detail::split_up(std::move(commandline));
+    // remove all empty strings
+    args.erase(std::remove(args.begin(), args.end(), std::string{}), args.end());
+    std::reverse(args.begin(), args.end());
+
+    parse(std::move(args));
+}
+
+CLI11_INLINE void App::parse(std::vector<std::string> &args) {
+    // Clear if parsed
+    if(parsed_ > 0)
+        clear();
+
+    // parsed_ is incremented in commands/subcommands,
+    // but placed here to make sure this is cleared when
+    // running parse after an error is thrown, even by _validate or _configure.
+    parsed_ = 1;
+    _validate();
+    _configure();
+    // set the parent as nullptr as this object should be the top now
+    parent_ = nullptr;
+    parsed_ = 0;
+
+    _parse(args);
+    run_callback();
+}
+
+CLI11_INLINE void App::parse(std::vector<std::string> &&args) {
+    // Clear if parsed
+    if(parsed_ > 0)
+        clear();
+
+    // parsed_ is incremented in commands/subcommands,
+    // but placed here to make sure this is cleared when
+    // running parse after an error is thrown, even by _validate or _configure.
+    parsed_ = 1;
+    _validate();
+    _configure();
+    // set the parent as nullptr as this object should be the top now
+    parent_ = nullptr;
+    parsed_ = 0;
+
+    _parse(std::move(args));
+    run_callback();
+}
+
+CLI11_INLINE void App::parse_from_stream(std::istream &input) {
+    if(parsed_ == 0) {
+        _validate();
+        _configure();
+        // set the parent as nullptr as this object should be the top now
+    }
+
+    _parse_stream(input);
+    run_callback();
+}
+
+CLI11_INLINE int App::exit(const Error &e, std::ostream &out, std::ostream &err) const {
+
+    /// Avoid printing anything if this is a CLI::RuntimeError
+    if(e.get_name() == "RuntimeError")
+        return e.get_exit_code();
+
+    if(e.get_name() == "CallForHelp") {
+        out << help();
+        return e.get_exit_code();
+    }
+
+    if(e.get_name() == "CallForAllHelp") {
+        out << help("", AppFormatMode::All);
+        return e.get_exit_code();
+    }
+
+    if(e.get_name() == "CallForVersion") {
+        out << e.what() << std::endl;
+        return e.get_exit_code();
+    }
+
+    if(e.get_exit_code() != static_cast<int>(ExitCodes::Success)) {
+        if(failure_message_)
+            err << failure_message_(this, e) << std::flush;
+    }
+
+    return e.get_exit_code();
+}
+
+CLI11_INLINE std::vector<const App *> App::get_subcommands(const std::function<bool(const App *)> &filter) const {
+    std::vector<const App *> subcomms(subcommands_.size());
+    std::transform(
+        std::begin(subcommands_), std::end(subcommands_), std::begin(subcomms), [](const App_p &v) { return v.get(); });
+
+    if(filter) {
+        subcomms.erase(std::remove_if(std::begin(subcomms),
+                                      std::end(subcomms),
+                                      [&filter](const App *app) { return !filter(app); }),
+                       std::end(subcomms));
+    }
+
+    return subcomms;
+}
+
+CLI11_INLINE std::vector<App *> App::get_subcommands(const std::function<bool(App *)> &filter) {
+    std::vector<App *> subcomms(subcommands_.size());
+    std::transform(
+        std::begin(subcommands_), std::end(subcommands_), std::begin(subcomms), [](const App_p &v) { return v.get(); });
+
+    if(filter) {
+        subcomms.erase(
+            std::remove_if(std::begin(subcomms), std::end(subcomms), [&filter](App *app) { return !filter(app); }),
+            std::end(subcomms));
+    }
+
+    return subcomms;
+}
+
+CLI11_INLINE bool App::remove_excludes(Option *opt) {
+    auto iterator = std::find(std::begin(exclude_options_), std::end(exclude_options_), opt);
+    if(iterator == std::end(exclude_options_)) {
+        return false;
+    }
+    exclude_options_.erase(iterator);
+    return true;
+}
+
+CLI11_INLINE bool App::remove_excludes(App *app) {
+    auto iterator = std::find(std::begin(exclude_subcommands_), std::end(exclude_subcommands_), app);
+    if(iterator == std::end(exclude_subcommands_)) {
+        return false;
+    }
+    auto *other_app = *iterator;
+    exclude_subcommands_.erase(iterator);
+    other_app->remove_excludes(this);
+    return true;
+}
+
+CLI11_INLINE bool App::remove_needs(Option *opt) {
+    auto iterator = std::find(std::begin(need_options_), std::end(need_options_), opt);
+    if(iterator == std::end(need_options_)) {
+        return false;
+    }
+    need_options_.erase(iterator);
+    return true;
+}
+
+CLI11_INLINE bool App::remove_needs(App *app) {
+    auto iterator = std::find(std::begin(need_subcommands_), std::end(need_subcommands_), app);
+    if(iterator == std::end(need_subcommands_)) {
+        return false;
+    }
+    need_subcommands_.erase(iterator);
+    return true;
+}
+
+CLI11_NODISCARD CLI11_INLINE std::string App::help(std::string prev, AppFormatMode mode) const {
+    if(prev.empty())
+        prev = get_name();
+    else
+        prev += " " + get_name();
+
+    // Delegate to subcommand if needed
+    auto selected_subcommands = get_subcommands();
+    if(!selected_subcommands.empty()) {
+        return selected_subcommands.at(0)->help(prev, mode);
+    }
+    return formatter_->make_help(this, prev, mode);
+}
+
+CLI11_NODISCARD CLI11_INLINE std::string App::version() const {
+    std::string val;
+    if(version_ptr_ != nullptr) {
+        auto rv = version_ptr_->results();
+        version_ptr_->clear();
+        version_ptr_->add_result("true");
+        try {
+            version_ptr_->run_callback();
+        } catch(const CLI::CallForVersion &cfv) {
+            val = cfv.what();
+        }
+        version_ptr_->clear();
+        version_ptr_->add_result(rv);
+    }
+    return val;
+}
+
+CLI11_INLINE std::vector<const Option *> App::get_options(const std::function<bool(const Option *)> filter) const {
+    std::vector<const Option *> options(options_.size());
+    std::transform(
+        std::begin(options_), std::end(options_), std::begin(options), [](const Option_p &val) { return val.get(); });
+
+    if(filter) {
+        options.erase(std::remove_if(std::begin(options),
+                                     std::end(options),
+                                     [&filter](const Option *opt) { return !filter(opt); }),
+                      std::end(options));
+    }
+
+    return options;
+}
+
+CLI11_INLINE std::vector<Option *> App::get_options(const std::function<bool(Option *)> filter) {
+    std::vector<Option *> options(options_.size());
+    std::transform(
+        std::begin(options_), std::end(options_), std::begin(options), [](const Option_p &val) { return val.get(); });
+
+    if(filter) {
+        options.erase(
+            std::remove_if(std::begin(options), std::end(options), [&filter](Option *opt) { return !filter(opt); }),
+            std::end(options));
+    }
+
+    return options;
+}
+
+CLI11_INLINE Option *App::get_option_no_throw(std::string option_name) noexcept {
+    for(Option_p &opt : options_) {
+        if(opt->check_name(option_name)) {
+            return opt.get();
+        }
+    }
+    for(auto &subc : subcommands_) {
+        // also check down into nameless subcommands
+        if(subc->get_name().empty()) {
+            auto *opt = subc->get_option_no_throw(option_name);
+            if(opt != nullptr) {
+                return opt;
+            }
+        }
+    }
+    return nullptr;
+}
+
+CLI11_NODISCARD CLI11_INLINE const Option *App::get_option_no_throw(std::string option_name) const noexcept {
+    for(const Option_p &opt : options_) {
+        if(opt->check_name(option_name)) {
+            return opt.get();
+        }
+    }
+    for(const auto &subc : subcommands_) {
+        // also check down into nameless subcommands
+        if(subc->get_name().empty()) {
+            auto *opt = subc->get_option_no_throw(option_name);
+            if(opt != nullptr) {
+                return opt;
+            }
+        }
+    }
+    return nullptr;
+}
+
+CLI11_NODISCARD CLI11_INLINE std::string App::get_display_name(bool with_aliases) const {
+    if(name_.empty()) {
+        return std::string("[Option Group: ") + get_group() + "]";
+    }
+    if(aliases_.empty() || !with_aliases) {
+        return name_;
+    }
+    std::string dispname = name_;
+    for(const auto &lalias : aliases_) {
+        dispname.push_back(',');
+        dispname.push_back(' ');
+        dispname.append(lalias);
+    }
+    return dispname;
+}
+
+CLI11_NODISCARD CLI11_INLINE bool App::check_name(std::string name_to_check) const {
+    std::string local_name = name_;
+    if(ignore_underscore_) {
+        local_name = detail::remove_underscore(name_);
+        name_to_check = detail::remove_underscore(name_to_check);
+    }
+    if(ignore_case_) {
+        local_name = detail::to_lower(name_);
+        name_to_check = detail::to_lower(name_to_check);
+    }
+
+    if(local_name == name_to_check) {
+        return true;
+    }
+    for(auto les : aliases_) {  // NOLINT(performance-for-range-copy)
+        if(ignore_underscore_) {
+            les = detail::remove_underscore(les);
+        }
+        if(ignore_case_) {
+            les = detail::to_lower(les);
+        }
+        if(les == name_to_check) {
+            return true;
+        }
+    }
+    return false;
+}
+
+CLI11_NODISCARD CLI11_INLINE std::vector<std::string> App::get_groups() const {
+    std::vector<std::string> groups;
+
+    for(const Option_p &opt : options_) {
+        // Add group if it is not already in there
+        if(std::find(groups.begin(), groups.end(), opt->get_group()) == groups.end()) {
+            groups.push_back(opt->get_group());
+        }
+    }
+
+    return groups;
+}
+
+CLI11_NODISCARD CLI11_INLINE std::vector<std::string> App::remaining(bool recurse) const {
+    std::vector<std::string> miss_list;
+    for(const std::pair<detail::Classifier, std::string> &miss : missing_) {
+        miss_list.push_back(std::get<1>(miss));
+    }
+    // Get from a subcommand that may allow extras
+    if(recurse) {
+        if(!allow_extras_) {
+            for(const auto &sub : subcommands_) {
+                if(sub->name_.empty() && !sub->missing_.empty()) {
+                    for(const std::pair<detail::Classifier, std::string> &miss : sub->missing_) {
+                        miss_list.push_back(std::get<1>(miss));
+                    }
+                }
+            }
+        }
+        // Recurse into subcommands
+
+        for(const App *sub : parsed_subcommands_) {
+            std::vector<std::string> output = sub->remaining(recurse);
+            std::copy(std::begin(output), std::end(output), std::back_inserter(miss_list));
+        }
+    }
+    return miss_list;
+}
+
+CLI11_NODISCARD CLI11_INLINE std::vector<std::string> App::remaining_for_passthrough(bool recurse) const {
+    std::vector<std::string> miss_list = remaining(recurse);
+    std::reverse(std::begin(miss_list), std::end(miss_list));
+    return miss_list;
+}
+
+CLI11_NODISCARD CLI11_INLINE std::size_t App::remaining_size(bool recurse) const {
+    auto remaining_options = static_cast<std::size_t>(std::count_if(
+        std::begin(missing_), std::end(missing_), [](const std::pair<detail::Classifier, std::string> &val) {
+            return val.first != detail::Classifier::POSITIONAL_MARK;
+        }));
+
+    if(recurse) {
+        for(const App_p &sub : subcommands_) {
+            remaining_options += sub->remaining_size(recurse);
+        }
+    }
+    return remaining_options;
+}
+
+CLI11_INLINE void App::_validate() const {
+    // count the number of positional only args
+    auto pcount = std::count_if(std::begin(options_), std::end(options_), [](const Option_p &opt) {
+        return opt->get_items_expected_max() >= detail::expected_max_vector_size && !opt->nonpositional();
+    });
+    if(pcount > 1) {
+        auto pcount_req = std::count_if(std::begin(options_), std::end(options_), [](const Option_p &opt) {
+            return opt->get_items_expected_max() >= detail::expected_max_vector_size && !opt->nonpositional() &&
+                   opt->get_required();
+        });
+        if(pcount - pcount_req > 1) {
+            throw InvalidError(name_);
+        }
+    }
+
+    std::size_t nameless_subs{0};
+    for(const App_p &app : subcommands_) {
+        app->_validate();
+        if(app->get_name().empty())
+            ++nameless_subs;
+    }
+
+    if(require_option_min_ > 0) {
+        if(require_option_max_ > 0) {
+            if(require_option_max_ < require_option_min_) {
+                throw(InvalidError("Required min options greater than required max options", ExitCodes::InvalidError));
+            }
+        }
+        if(require_option_min_ > (options_.size() + nameless_subs)) {
+            throw(
+                InvalidError("Required min options greater than number of available options", ExitCodes::InvalidError));
+        }
+    }
+}
+
+CLI11_INLINE void App::_configure() {
+    if(default_startup == startup_mode::enabled) {
+        disabled_ = false;
+    } else if(default_startup == startup_mode::disabled) {
+        disabled_ = true;
+    }
+    for(const App_p &app : subcommands_) {
+        if(app->has_automatic_name_) {
+            app->name_.clear();
+        }
+        if(app->name_.empty()) {
+            app->fallthrough_ = false;  // make sure fallthrough_ is false to prevent infinite loop
+            app->prefix_command_ = false;
+        }
+        // make sure the parent is set to be this object in preparation for parse
+        app->parent_ = this;
+        app->_configure();
+    }
+}
+
+CLI11_INLINE void App::run_callback(bool final_mode, bool suppress_final_callback) {
+    pre_callback();
+    // in the main app if immediate_callback_ is set it runs the main callback before the used subcommands
+    if(!final_mode && parse_complete_callback_) {
+        parse_complete_callback_();
+    }
+    // run the callbacks for the received subcommands
+    for(App *subc : get_subcommands()) {
+        if(subc->parent_ == this) {
+            subc->run_callback(true, suppress_final_callback);
+        }
+    }
+    // now run callbacks for option_groups
+    for(auto &subc : subcommands_) {
+        if(subc->name_.empty() && subc->count_all() > 0) {
+            subc->run_callback(true, suppress_final_callback);
+        }
+    }
+
+    // finally run the main callback
+    if(final_callback_ && (parsed_ > 0) && (!suppress_final_callback)) {
+        if(!name_.empty() || count_all() > 0 || parent_ == nullptr) {
+            final_callback_();
+        }
+    }
+}
+
+CLI11_NODISCARD CLI11_INLINE bool App::_valid_subcommand(const std::string &current, bool ignore_used) const {
+    // Don't match if max has been reached - but still check parents
+    if(require_subcommand_max_ != 0 && parsed_subcommands_.size() >= require_subcommand_max_) {
+        return parent_ != nullptr && parent_->_valid_subcommand(current, ignore_used);
+    }
+    auto *com = _find_subcommand(current, true, ignore_used);
+    if(com != nullptr) {
+        return true;
+    }
+    // Check parent if exists, else return false
+    return parent_ != nullptr && parent_->_valid_subcommand(current, ignore_used);
+}
+
+CLI11_NODISCARD CLI11_INLINE detail::Classifier App::_recognize(const std::string &current,
+                                                                bool ignore_used_subcommands) const {
+    std::string dummy1, dummy2;
+
+    if(current == "--")
+        return detail::Classifier::POSITIONAL_MARK;
+    if(_valid_subcommand(current, ignore_used_subcommands))
+        return detail::Classifier::SUBCOMMAND;
+    if(detail::split_long(current, dummy1, dummy2))
+        return detail::Classifier::LONG;
+    if(detail::split_short(current, dummy1, dummy2)) {
+        if(dummy1[0] >= '0' && dummy1[0] <= '9') {
+            if(get_option_no_throw(std::string{'-', dummy1[0]}) == nullptr) {
+                return detail::Classifier::NONE;
+            }
+        }
+        return detail::Classifier::SHORT;
+    }
+    if((allow_windows_style_options_) && (detail::split_windows_style(current, dummy1, dummy2)))
+        return detail::Classifier::WINDOWS_STYLE;
+    if((current == "++") && !name_.empty() && parent_ != nullptr)
+        return detail::Classifier::SUBCOMMAND_TERMINATOR;
+    return detail::Classifier::NONE;
+}
+
+CLI11_INLINE void App::_process_config_file() {
+    if(config_ptr_ != nullptr) {
+        bool config_required = config_ptr_->get_required();
+        auto file_given = config_ptr_->count() > 0;
+        auto config_files = config_ptr_->as<std::vector<std::string>>();
+        if(config_files.empty() || config_files.front().empty()) {
+            if(config_required) {
+                throw FileError::Missing("no specified config file");
+            }
+            return;
+        }
+        for(auto rit = config_files.rbegin(); rit != config_files.rend(); ++rit) {
+            const auto &config_file = *rit;
+            auto path_result = detail::check_path(config_file.c_str());
+            if(path_result == detail::path_type::file) {
+                try {
+                    std::vector<ConfigItem> values = config_formatter_->from_file(config_file);
+                    _parse_config(values);
+                    if(!file_given) {
+                        config_ptr_->add_result(config_file);
+                    }
+                } catch(const FileError &) {
+                    if(config_required || file_given)
+                        throw;
+                }
+            } else if(config_required || file_given) {
+                throw FileError::Missing(config_file);
+            }
+        }
+    }
+}
+
+CLI11_INLINE void App::_process_env() {
+    for(const Option_p &opt : options_) {
+        if(opt->count() == 0 && !opt->envname_.empty()) {
+            char *buffer = nullptr;
+            std::string ename_string;
+
+#ifdef _MSC_VER
+            // Windows version
+            std::size_t sz = 0;
+            if(_dupenv_s(&buffer, &sz, opt->envname_.c_str()) == 0 && buffer != nullptr) {
+                ename_string = std::string(buffer);
+                free(buffer);
+            }
+#else
+            // This also works on Windows, but gives a warning
+            buffer = std::getenv(opt->envname_.c_str());
+            if(buffer != nullptr)
+                ename_string = std::string(buffer);
+#endif
+
+            if(!ename_string.empty()) {
+                opt->add_result(ename_string);
+            }
+        }
+    }
+
+    for(App_p &sub : subcommands_) {
+        if(sub->get_name().empty() || !sub->parse_complete_callback_)
+            sub->_process_env();
+    }
+}
+
+CLI11_INLINE void App::_process_callbacks() {
+
+    for(App_p &sub : subcommands_) {
+        // process the priority option_groups first
+        if(sub->get_name().empty() && sub->parse_complete_callback_) {
+            if(sub->count_all() > 0) {
+                sub->_process_callbacks();
+                sub->run_callback();
+            }
+        }
+    }
+
+    for(const Option_p &opt : options_) {
+        if((*opt) && !opt->get_callback_run()) {
+            opt->run_callback();
+        }
+    }
+    for(App_p &sub : subcommands_) {
+        if(!sub->parse_complete_callback_) {
+            sub->_process_callbacks();
+        }
+    }
+}
+
+CLI11_INLINE void App::_process_help_flags(bool trigger_help, bool trigger_all_help) const {
+    const Option *help_ptr = get_help_ptr();
+    const Option *help_all_ptr = get_help_all_ptr();
+
+    if(help_ptr != nullptr && help_ptr->count() > 0)
+        trigger_help = true;
+    if(help_all_ptr != nullptr && help_all_ptr->count() > 0)
+        trigger_all_help = true;
+
+    // If there were parsed subcommands, call those. First subcommand wins if there are multiple ones.
+    if(!parsed_subcommands_.empty()) {
+        for(const App *sub : parsed_subcommands_)
+            sub->_process_help_flags(trigger_help, trigger_all_help);
+
+        // Only the final subcommand should call for help. All help wins over help.
+    } else if(trigger_all_help) {
+        throw CallForAllHelp();
+    } else if(trigger_help) {
+        throw CallForHelp();
+    }
+}
+
+CLI11_INLINE void App::_process_requirements() {
+    // check excludes
+    bool excluded{false};
+    std::string excluder;
+    for(const auto &opt : exclude_options_) {
+        if(opt->count() > 0) {
+            excluded = true;
+            excluder = opt->get_name();
+        }
+    }
+    for(const auto &subc : exclude_subcommands_) {
+        if(subc->count_all() > 0) {
+            excluded = true;
+            excluder = subc->get_display_name();
+        }
+    }
+    if(excluded) {
+        if(count_all() > 0) {
+            throw ExcludesError(get_display_name(), excluder);
+        }
+        // if we are excluded but didn't receive anything, just return
+        return;
+    }
+
+    // check excludes
+    bool missing_needed{false};
+    std::string missing_need;
+    for(const auto &opt : need_options_) {
+        if(opt->count() == 0) {
+            missing_needed = true;
+            missing_need = opt->get_name();
+        }
+    }
+    for(const auto &subc : need_subcommands_) {
+        if(subc->count_all() == 0) {
+            missing_needed = true;
+            missing_need = subc->get_display_name();
+        }
+    }
+    if(missing_needed) {
+        if(count_all() > 0) {
+            throw RequiresError(get_display_name(), missing_need);
+        }
+        // if we missing something but didn't have any options, just return
+        return;
+    }
+
+    std::size_t used_options = 0;
+    for(const Option_p &opt : options_) {
+
+        if(opt->count() != 0) {
+            ++used_options;
+        }
+        // Required but empty
+        if(opt->get_required() && opt->count() == 0) {
+            throw RequiredError(opt->get_name());
+        }
+        // Requires
+        for(const Option *opt_req : opt->needs_)
+            if(opt->count() > 0 && opt_req->count() == 0)
+                throw RequiresError(opt->get_name(), opt_req->get_name());
+        // Excludes
+        for(const Option *opt_ex : opt->excludes_)
+            if(opt->count() > 0 && opt_ex->count() != 0)
+                throw ExcludesError(opt->get_name(), opt_ex->get_name());
+    }
+    // check for the required number of subcommands
+    if(require_subcommand_min_ > 0) {
+        auto selected_subcommands = get_subcommands();
+        if(require_subcommand_min_ > selected_subcommands.size())
+            throw RequiredError::Subcommand(require_subcommand_min_);
+    }
+
+    // Max error cannot occur, the extra subcommand will parse as an ExtrasError or a remaining item.
+
+    // run this loop to check how many unnamed subcommands were actually used since they are considered options
+    // from the perspective of an App
+    for(App_p &sub : subcommands_) {
+        if(sub->disabled_)
+            continue;
+        if(sub->name_.empty() && sub->count_all() > 0) {
+            ++used_options;
+        }
+    }
+
+    if(require_option_min_ > used_options || (require_option_max_ > 0 && require_option_max_ < used_options)) {
+        auto option_list = detail::join(options_, [this](const Option_p &ptr) {
+            if(ptr.get() == help_ptr_ || ptr.get() == help_all_ptr_) {
+                return std::string{};
+            }
+            return ptr->get_name(false, true);
+        });
+
+        auto subc_list = get_subcommands([](App *app) { return ((app->get_name().empty()) && (!app->disabled_)); });
+        if(!subc_list.empty()) {
+            option_list += "," + detail::join(subc_list, [](const App *app) { return app->get_display_name(); });
+        }
+        throw RequiredError::Option(require_option_min_, require_option_max_, used_options, option_list);
+    }
+
+    // now process the requirements for subcommands if needed
+    for(App_p &sub : subcommands_) {
+        if(sub->disabled_)
+            continue;
+        if(sub->name_.empty() && sub->required_ == false) {
+            if(sub->count_all() == 0) {
+                if(require_option_min_ > 0 && require_option_min_ <= used_options) {
+                    continue;
+                    // if we have met the requirement and there is nothing in this option group skip checking
+                    // requirements
+                }
+                if(require_option_max_ > 0 && used_options >= require_option_min_) {
+                    continue;
+                    // if we have met the requirement and there is nothing in this option group skip checking
+                    // requirements
+                }
+            }
+        }
+        if(sub->count() > 0 || sub->name_.empty()) {
+            sub->_process_requirements();
+        }
+
+        if(sub->required_ && sub->count_all() == 0) {
+            throw(CLI::RequiredError(sub->get_display_name()));
+        }
+    }
+}
+
+CLI11_INLINE void App::_process() {
+    try {
+        // the config file might generate a FileError but that should not be processed until later in the process
+        // to allow for help, version and other errors to generate first.
+        _process_config_file();
+
+        // process env shouldn't throw but no reason to process it if config generated an error
+        _process_env();
+    } catch(const CLI::FileError &) {
+        // callbacks and help_flags can generate exceptions which should take priority
+        // over the config file error if one exists.
+        _process_callbacks();
+        _process_help_flags();
+        throw;
+    }
+
+    _process_callbacks();
+    _process_help_flags();
+
+    _process_requirements();
+}
+
+CLI11_INLINE void App::_process_extras() {
+    if(!(allow_extras_ || prefix_command_)) {
+        std::size_t num_left_over = remaining_size();
+        if(num_left_over > 0) {
+            throw ExtrasError(name_, remaining(false));
+        }
+    }
+
+    for(App_p &sub : subcommands_) {
+        if(sub->count() > 0)
+            sub->_process_extras();
+    }
+}
+
+CLI11_INLINE void App::_process_extras(std::vector<std::string> &args) {
+    if(!(allow_extras_ || prefix_command_)) {
+        std::size_t num_left_over = remaining_size();
+        if(num_left_over > 0) {
+            args = remaining(false);
+            throw ExtrasError(name_, args);
+        }
+    }
+
+    for(App_p &sub : subcommands_) {
+        if(sub->count() > 0)
+            sub->_process_extras(args);
+    }
+}
+
+CLI11_INLINE void App::increment_parsed() {
+    ++parsed_;
+    for(App_p &sub : subcommands_) {
+        if(sub->get_name().empty())
+            sub->increment_parsed();
+    }
+}
+
+CLI11_INLINE void App::_parse(std::vector<std::string> &args) {
+    increment_parsed();
+    _trigger_pre_parse(args.size());
+    bool positional_only = false;
+
+    while(!args.empty()) {
+        if(!_parse_single(args, positional_only)) {
+            break;
+        }
+    }
+
+    if(parent_ == nullptr) {
+        _process();
+
+        // Throw error if any items are left over (depending on settings)
+        _process_extras(args);
+
+        // Convert missing (pairs) to extras (string only) ready for processing in another app
+        args = remaining_for_passthrough(false);
+    } else if(parse_complete_callback_) {
+        _process_env();
+        _process_callbacks();
+        _process_help_flags();
+        _process_requirements();
+        run_callback(false, true);
+    }
+}
+
+CLI11_INLINE void App::_parse(std::vector<std::string> &&args) {
+    // this can only be called by the top level in which case parent == nullptr by definition
+    // operation is simplified
+    increment_parsed();
+    _trigger_pre_parse(args.size());
+    bool positional_only = false;
+
+    while(!args.empty()) {
+        _parse_single(args, positional_only);
+    }
+    _process();
+
+    // Throw error if any items are left over (depending on settings)
+    _process_extras();
+}
+
+CLI11_INLINE void App::_parse_stream(std::istream &input) {
+    auto values = config_formatter_->from_config(input);
+    _parse_config(values);
+    increment_parsed();
+    _trigger_pre_parse(values.size());
+    _process();
+
+    // Throw error if any items are left over (depending on settings)
+    _process_extras();
+}
+
+CLI11_INLINE void App::_parse_config(const std::vector<ConfigItem> &args) {
+    for(const ConfigItem &item : args) {
+        if(!_parse_single_config(item) && allow_config_extras_ == config_extras_mode::error)
+            throw ConfigError::Extras(item.fullname());
+    }
+}
+
+CLI11_INLINE bool App::_parse_single_config(const ConfigItem &item, std::size_t level) {
+    if(level < item.parents.size()) {
+        try {
+            auto *subcom = get_subcommand(item.parents.at(level));
+            auto result = subcom->_parse_single_config(item, level + 1);
+
+            return result;
+        } catch(const OptionNotFound &) {
+            return false;
+        }
+    }
+    // check for section open
+    if(item.name == "++") {
+        if(configurable_) {
+            increment_parsed();
+            _trigger_pre_parse(2);
+            if(parent_ != nullptr) {
+                parent_->parsed_subcommands_.push_back(this);
+            }
+        }
+        return true;
+    }
+    // check for section close
+    if(item.name == "--") {
+        if(configurable_ && parse_complete_callback_) {
+            _process_callbacks();
+            _process_requirements();
+            run_callback();
+        }
+        return true;
+    }
+    Option *op = get_option_no_throw("--" + item.name);
+    if(op == nullptr) {
+        if(item.name.size() == 1) {
+            op = get_option_no_throw("-" + item.name);
+        }
+    }
+    if(op == nullptr) {
+        op = get_option_no_throw(item.name);
+    }
+    if(op == nullptr) {
+        // If the option was not present
+        if(get_allow_config_extras() == config_extras_mode::capture)
+            // Should we worry about classifying the extras properly?
+            missing_.emplace_back(detail::Classifier::NONE, item.fullname());
+        return false;
+    }
+
+    if(!op->get_configurable()) {
+        if(get_allow_config_extras() == config_extras_mode::ignore_all) {
+            return false;
+        }
+        throw ConfigError::NotConfigurable(item.fullname());
+    }
+
+    if(op->empty()) {
+
+        if(op->get_expected_min() == 0) {
+            // Flag parsing
+            auto res = config_formatter_->to_flag(item);
+            res = op->get_flag_value(item.name, res);
+
+            op->add_result(res);
+
+        } else {
+            op->add_result(item.inputs);
+            op->run_callback();
+        }
+    }
+
+    return true;
+}
+
+CLI11_INLINE bool App::_parse_single(std::vector<std::string> &args, bool &positional_only) {
+    bool retval = true;
+    detail::Classifier classifier = positional_only ? detail::Classifier::NONE : _recognize(args.back());
+    switch(classifier) {
+    case detail::Classifier::POSITIONAL_MARK:
+        args.pop_back();
+        positional_only = true;
+        if((!_has_remaining_positionals()) && (parent_ != nullptr)) {
+            retval = false;
+        } else {
+            _move_to_missing(classifier, "--");
+        }
+        break;
+    case detail::Classifier::SUBCOMMAND_TERMINATOR:
+        // treat this like a positional mark if in the parent app
+        args.pop_back();
+        retval = false;
+        break;
+    case detail::Classifier::SUBCOMMAND:
+        retval = _parse_subcommand(args);
+        break;
+    case detail::Classifier::LONG:
+    case detail::Classifier::SHORT:
+    case detail::Classifier::WINDOWS_STYLE:
+        // If already parsed a subcommand, don't accept options_
+        _parse_arg(args, classifier);
+        break;
+    case detail::Classifier::NONE:
+        // Probably a positional or something for a parent (sub)command
+        retval = _parse_positional(args, false);
+        if(retval && positionals_at_end_) {
+            positional_only = true;
+        }
+        break;
+        // LCOV_EXCL_START
+    default:
+        throw HorribleError("unrecognized classifier (you should not see this!)");
+        // LCOV_EXCL_STOP
+    }
+    return retval;
+}
+
+CLI11_NODISCARD CLI11_INLINE std::size_t App::_count_remaining_positionals(bool required_only) const {
+    std::size_t retval = 0;
+    for(const Option_p &opt : options_) {
+        if(opt->get_positional() && (!required_only || opt->get_required())) {
+            if(opt->get_items_expected_min() > 0 && static_cast<int>(opt->count()) < opt->get_items_expected_min()) {
+                retval += static_cast<std::size_t>(opt->get_items_expected_min()) - opt->count();
+            }
+        }
+    }
+    return retval;
+}
+
+CLI11_NODISCARD CLI11_INLINE bool App::_has_remaining_positionals() const {
+    for(const Option_p &opt : options_) {
+        if(opt->get_positional() && ((static_cast<int>(opt->count()) < opt->get_items_expected_min()))) {
+            return true;
+        }
+    }
+
+    return false;
+}
+
+CLI11_INLINE bool App::_parse_positional(std::vector<std::string> &args, bool haltOnSubcommand) {
+
+    const std::string &positional = args.back();
+
+    if(positionals_at_end_) {
+        // deal with the case of required arguments at the end which should take precedence over other arguments
+        auto arg_rem = args.size();
+        auto remreq = _count_remaining_positionals(true);
+        if(arg_rem <= remreq) {
+            for(const Option_p &opt : options_) {
+                if(opt->get_positional() && opt->required_) {
+                    if(static_cast<int>(opt->count()) < opt->get_items_expected_min()) {
+                        if(validate_positionals_) {
+                            std::string pos = positional;
+                            pos = opt->_validate(pos, 0);
+                            if(!pos.empty()) {
+                                continue;
+                            }
+                        }
+
+                        parse_order_.push_back(opt.get());
+                        /// if we require a separator add it here
+                        if(opt->get_inject_separator()) {
+                            if(!opt->results().empty() && !opt->results().back().empty()) {
+                                opt->add_result(std::string{});
+                            }
+                        }
+                        if(opt->get_trigger_on_parse() &&
+                           opt->current_option_state_ == Option::option_state::callback_run) {
+                            opt->clear();
+                        }
+                        opt->add_result(positional);
+                        if(opt->get_trigger_on_parse()) {
+                            opt->run_callback();
+                        }
+                        args.pop_back();
+                        return true;
+                    }
+                }
+            }
+        }
+    }
+    for(const Option_p &opt : options_) {
+        // Eat options, one by one, until done
+        if(opt->get_positional() &&
+           (static_cast<int>(opt->count()) < opt->get_items_expected_min() || opt->get_allow_extra_args())) {
+            if(validate_positionals_) {
+                std::string pos = positional;
+                pos = opt->_validate(pos, 0);
+                if(!pos.empty()) {
+                    continue;
+                }
+            }
+            if(opt->get_inject_separator()) {
+                if(!opt->results().empty() && !opt->results().back().empty()) {
+                    opt->add_result(std::string{});
+                }
+            }
+            if(opt->get_trigger_on_parse() && opt->current_option_state_ == Option::option_state::callback_run) {
+                opt->clear();
+            }
+            opt->add_result(positional);
+            if(opt->get_trigger_on_parse()) {
+                opt->run_callback();
+            }
+            parse_order_.push_back(opt.get());
+            args.pop_back();
+            return true;
+        }
+    }
+
+    for(auto &subc : subcommands_) {
+        if((subc->name_.empty()) && (!subc->disabled_)) {
+            if(subc->_parse_positional(args, false)) {
+                if(!subc->pre_parse_called_) {
+                    subc->_trigger_pre_parse(args.size());
+                }
+                return true;
+            }
+        }
+    }
+    // let the parent deal with it if possible
+    if(parent_ != nullptr && fallthrough_)
+        return _get_fallthrough_parent()->_parse_positional(args, static_cast<bool>(parse_complete_callback_));
+
+    /// Try to find a local subcommand that is repeated
+    auto *com = _find_subcommand(args.back(), true, false);
+    if(com != nullptr && (require_subcommand_max_ == 0 || require_subcommand_max_ > parsed_subcommands_.size())) {
+        if(haltOnSubcommand) {
+            return false;
+        }
+        args.pop_back();
+        com->_parse(args);
+        return true;
+    }
+    /// now try one last gasp at subcommands that have been executed before, go to root app and try to find a
+    /// subcommand in a broader way, if one exists let the parent deal with it
+    auto *parent_app = (parent_ != nullptr) ? _get_fallthrough_parent() : this;
+    com = parent_app->_find_subcommand(args.back(), true, false);
+    if(com != nullptr && (com->parent_->require_subcommand_max_ == 0 ||
+                          com->parent_->require_subcommand_max_ > com->parent_->parsed_subcommands_.size())) {
+        return false;
+    }
+
+    if(positionals_at_end_) {
+        throw CLI::ExtrasError(name_, args);
+    }
+    /// If this is an option group don't deal with it
+    if(parent_ != nullptr && name_.empty()) {
+        return false;
+    }
+    /// We are out of other options this goes to missing
+    _move_to_missing(detail::Classifier::NONE, positional);
+    args.pop_back();
+    if(prefix_command_) {
+        while(!args.empty()) {
+            _move_to_missing(detail::Classifier::NONE, args.back());
+            args.pop_back();
+        }
+    }
+
+    return true;
+}
+
+CLI11_NODISCARD CLI11_INLINE App *
+App::_find_subcommand(const std::string &subc_name, bool ignore_disabled, bool ignore_used) const noexcept {
+    for(const App_p &com : subcommands_) {
+        if(com->disabled_ && ignore_disabled)
+            continue;
+        if(com->get_name().empty()) {
+            auto *subc = com->_find_subcommand(subc_name, ignore_disabled, ignore_used);
+            if(subc != nullptr) {
+                return subc;
+            }
+        }
+        if(com->check_name(subc_name)) {
+            if((!*com) || !ignore_used)
+                return com.get();
+        }
+    }
+    return nullptr;
+}
+
+CLI11_INLINE bool App::_parse_subcommand(std::vector<std::string> &args) {
+    if(_count_remaining_positionals(/* required */ true) > 0) {
+        _parse_positional(args, false);
+        return true;
+    }
+    auto *com = _find_subcommand(args.back(), true, true);
+    if(com != nullptr) {
+        args.pop_back();
+        if(!com->silent_) {
+            parsed_subcommands_.push_back(com);
+        }
+        com->_parse(args);
+        auto *parent_app = com->parent_;
+        while(parent_app != this) {
+            parent_app->_trigger_pre_parse(args.size());
+            if(!com->silent_) {
+                parent_app->parsed_subcommands_.push_back(com);
+            }
+            parent_app = parent_app->parent_;
+        }
+        return true;
+    }
+
+    if(parent_ == nullptr)
+        throw HorribleError("Subcommand " + args.back() + " missing");
+    return false;
+}
+
+CLI11_INLINE bool App::_parse_arg(std::vector<std::string> &args, detail::Classifier current_type) {
+
+    std::string current = args.back();
+
+    std::string arg_name;
+    std::string value;
+    std::string rest;
+
+    switch(current_type) {
+    case detail::Classifier::LONG:
+        if(!detail::split_long(current, arg_name, value))
+            throw HorribleError("Long parsed but missing (you should not see this):" + args.back());
+        break;
+    case detail::Classifier::SHORT:
+        if(!detail::split_short(current, arg_name, rest))
+            throw HorribleError("Short parsed but missing! You should not see this");
+        break;
+    case detail::Classifier::WINDOWS_STYLE:
+        if(!detail::split_windows_style(current, arg_name, value))
+            throw HorribleError("windows option parsed but missing! You should not see this");
+        break;
+    case detail::Classifier::SUBCOMMAND:
+    case detail::Classifier::SUBCOMMAND_TERMINATOR:
+    case detail::Classifier::POSITIONAL_MARK:
+    case detail::Classifier::NONE:
+    default:
+        throw HorribleError("parsing got called with invalid option! You should not see this");
+    }
+
+    auto op_ptr = std::find_if(std::begin(options_), std::end(options_), [arg_name, current_type](const Option_p &opt) {
+        if(current_type == detail::Classifier::LONG)
+            return opt->check_lname(arg_name);
+        if(current_type == detail::Classifier::SHORT)
+            return opt->check_sname(arg_name);
+        // this will only get called for detail::Classifier::WINDOWS_STYLE
+        return opt->check_lname(arg_name) || opt->check_sname(arg_name);
+    });
+
+    // Option not found
+    if(op_ptr == std::end(options_)) {
+        for(auto &subc : subcommands_) {
+            if(subc->name_.empty() && !subc->disabled_) {
+                if(subc->_parse_arg(args, current_type)) {
+                    if(!subc->pre_parse_called_) {
+                        subc->_trigger_pre_parse(args.size());
+                    }
+                    return true;
+                }
+            }
+        }
+
+        // don't capture missing if this is a nameless subcommand and nameless subcommands can't fallthrough
+        if(parent_ != nullptr && name_.empty()) {
+            return false;
+        }
+
+        // If a subcommand, try the main command
+        if(parent_ != nullptr && fallthrough_)
+            return _get_fallthrough_parent()->_parse_arg(args, current_type);
+
+        // Otherwise, add to missing
+        args.pop_back();
+        _move_to_missing(current_type, current);
+        return true;
+    }
+
+    args.pop_back();
+
+    // Get a reference to the pointer to make syntax bearable
+    Option_p &op = *op_ptr;
+    /// if we require a separator add it here
+    if(op->get_inject_separator()) {
+        if(!op->results().empty() && !op->results().back().empty()) {
+            op->add_result(std::string{});
+        }
+    }
+    if(op->get_trigger_on_parse() && op->current_option_state_ == Option::option_state::callback_run) {
+        op->clear();
+    }
+    int min_num = (std::min)(op->get_type_size_min(), op->get_items_expected_min());
+    int max_num = op->get_items_expected_max();
+    // check container like options to limit the argument size to a single type if the allow_extra_flags argument is
+    // set. 16 is somewhat arbitrary (needs to be at least 4)
+    if(max_num >= detail::expected_max_vector_size / 16 && !op->get_allow_extra_args()) {
+        auto tmax = op->get_type_size_max();
+        max_num = detail::checked_multiply(tmax, op->get_expected_min()) ? tmax : detail::expected_max_vector_size;
+    }
+    // Make sure we always eat the minimum for unlimited vectors
+    int collected = 0;     // total number of arguments collected
+    int result_count = 0;  // local variable for number of results in a single arg string
+    // deal with purely flag like things
+    if(max_num == 0) {
+        auto res = op->get_flag_value(arg_name, value);
+        op->add_result(res);
+        parse_order_.push_back(op.get());
+    } else if(!value.empty()) {  // --this=value
+        op->add_result(value, result_count);
+        parse_order_.push_back(op.get());
+        collected += result_count;
+        // -Trest
+    } else if(!rest.empty()) {
+        op->add_result(rest, result_count);
+        parse_order_.push_back(op.get());
+        rest = "";
+        collected += result_count;
+    }
+
+    // gather the minimum number of arguments
+    while(min_num > collected && !args.empty()) {
+        std::string current_ = args.back();
+        args.pop_back();
+        op->add_result(current_, result_count);
+        parse_order_.push_back(op.get());
+        collected += result_count;
+    }
+
+    if(min_num > collected) {  // if we have run out of arguments and the minimum was not met
+        throw ArgumentMismatch::TypedAtLeast(op->get_name(), min_num, op->get_type_name());
+    }
+
+    // now check for optional arguments
+    if(max_num > collected || op->get_allow_extra_args()) {  // we allow optional arguments
+        auto remreqpos = _count_remaining_positionals(true);
+        // we have met the minimum now optionally check up to the maximum
+        while((collected < max_num || op->get_allow_extra_args()) && !args.empty() &&
+              _recognize(args.back(), false) == detail::Classifier::NONE) {
+            // If any required positionals remain, don't keep eating
+            if(remreqpos >= args.size()) {
+                break;
+            }
+            if(validate_optional_arguments_) {
+                std::string arg = args.back();
+                arg = op->_validate(arg, 0);
+                if(!arg.empty()) {
+                    break;
+                }
+            }
+            op->add_result(args.back(), result_count);
+            parse_order_.push_back(op.get());
+            args.pop_back();
+            collected += result_count;
+        }
+
+        // Allow -- to end an unlimited list and "eat" it
+        if(!args.empty() && _recognize(args.back()) == detail::Classifier::POSITIONAL_MARK)
+            args.pop_back();
+        // optional flag that didn't receive anything now get the default value
+        if(min_num == 0 && max_num > 0 && collected == 0) {
+            auto res = op->get_flag_value(arg_name, std::string{});
+            op->add_result(res);
+            parse_order_.push_back(op.get());
+        }
+    }
+    // if we only partially completed a type then add an empty string if allowed for later processing
+    if(min_num > 0 && (collected % op->get_type_size_max()) != 0) {
+        if(op->get_type_size_max() != op->get_type_size_min()) {
+            op->add_result(std::string{});
+        } else {
+            throw ArgumentMismatch::PartialType(op->get_name(), op->get_type_size_min(), op->get_type_name());
+        }
+    }
+    if(op->get_trigger_on_parse()) {
+        op->run_callback();
+    }
+    if(!rest.empty()) {
+        rest = "-" + rest;
+        args.push_back(rest);
+    }
+    return true;
+}
+
+CLI11_INLINE void App::_trigger_pre_parse(std::size_t remaining_args) {
+    if(!pre_parse_called_) {
+        pre_parse_called_ = true;
+        if(pre_parse_callback_) {
+            pre_parse_callback_(remaining_args);
+        }
+    } else if(immediate_callback_) {
+        if(!name_.empty()) {
+            auto pcnt = parsed_;
+            auto extras = std::move(missing_);
+            clear();
+            parsed_ = pcnt;
+            pre_parse_called_ = true;
+            missing_ = std::move(extras);
+        }
+    }
+}
+
+CLI11_INLINE App *App::_get_fallthrough_parent() {
+    if(parent_ == nullptr) {
+        throw(HorribleError("No Valid parent"));
+    }
+    auto *fallthrough_parent = parent_;
+    while((fallthrough_parent->parent_ != nullptr) && (fallthrough_parent->get_name().empty())) {
+        fallthrough_parent = fallthrough_parent->parent_;
+    }
+    return fallthrough_parent;
+}
+
+CLI11_NODISCARD CLI11_INLINE const std::string &App::_compare_subcommand_names(const App &subcom,
+                                                                               const App &base) const {
+    static const std::string estring;
+    if(subcom.disabled_) {
+        return estring;
+    }
+    for(const auto &subc : base.subcommands_) {
+        if(subc.get() != &subcom) {
+            if(subc->disabled_) {
+                continue;
+            }
+            if(!subcom.get_name().empty()) {
+                if(subc->check_name(subcom.get_name())) {
+                    return subcom.get_name();
+                }
+            }
+            if(!subc->get_name().empty()) {
+                if(subcom.check_name(subc->get_name())) {
+                    return subc->get_name();
+                }
+            }
+            for(const auto &les : subcom.aliases_) {
+                if(subc->check_name(les)) {
+                    return les;
+                }
+            }
+            // this loop is needed in case of ignore_underscore or ignore_case on one but not the other
+            for(const auto &les : subc->aliases_) {
+                if(subcom.check_name(les)) {
+                    return les;
+                }
+            }
+            // if the subcommand is an option group we need to check deeper
+            if(subc->get_name().empty()) {
+                const auto &cmpres = _compare_subcommand_names(subcom, *subc);
+                if(!cmpres.empty()) {
+                    return cmpres;
+                }
+            }
+            // if the test subcommand is an option group we need to check deeper
+            if(subcom.get_name().empty()) {
+                const auto &cmpres = _compare_subcommand_names(*subc, subcom);
+                if(!cmpres.empty()) {
+                    return cmpres;
+                }
+            }
+        }
+    }
+    return estring;
+}
+
+CLI11_INLINE void App::_move_to_missing(detail::Classifier val_type, const std::string &val) {
+    if(allow_extras_ || subcommands_.empty()) {
+        missing_.emplace_back(val_type, val);
+        return;
+    }
+    // allow extra arguments to be places in an option group if it is allowed there
+    for(auto &subc : subcommands_) {
+        if(subc->name_.empty() && subc->allow_extras_) {
+            subc->missing_.emplace_back(val_type, val);
+            return;
+        }
+    }
+    // if we haven't found any place to put them yet put them in missing
+    missing_.emplace_back(val_type, val);
+}
+
+CLI11_INLINE void App::_move_option(Option *opt, App *app) {
+    if(opt == nullptr) {
+        throw OptionNotFound("the option is NULL");
+    }
+    // verify that the give app is actually a subcommand
+    bool found = false;
+    for(auto &subc : subcommands_) {
+        if(app == subc.get()) {
+            found = true;
+        }
+    }
+    if(!found) {
+        throw OptionNotFound("The Given app is not a subcommand");
+    }
+
+    if((help_ptr_ == opt) || (help_all_ptr_ == opt))
+        throw OptionAlreadyAdded("cannot move help options");
+
+    if(config_ptr_ == opt)
+        throw OptionAlreadyAdded("cannot move config file options");
+
+    auto iterator =
+        std::find_if(std::begin(options_), std::end(options_), [opt](const Option_p &v) { return v.get() == opt; });
+    if(iterator != std::end(options_)) {
+        const auto &opt_p = *iterator;
+        if(std::find_if(std::begin(app->options_), std::end(app->options_), [&opt_p](const Option_p &v) {
+               return (*v == *opt_p);
+           }) == std::end(app->options_)) {
+            // only erase after the insertion was successful
+            app->options_.push_back(std::move(*iterator));
+            options_.erase(iterator);
+        } else {
+            throw OptionAlreadyAdded("option was not located: " + opt->get_name());
+        }
+    } else {
+        throw OptionNotFound("could not locate the given Option");
+    }
+}
+
+CLI11_INLINE void TriggerOn(App *trigger_app, App *app_to_enable) {
+    app_to_enable->enabled_by_default(false);
+    app_to_enable->disabled_by_default();
+    trigger_app->preparse_callback([app_to_enable](std::size_t) { app_to_enable->disabled(false); });
+}
+
+CLI11_INLINE void TriggerOn(App *trigger_app, std::vector<App *> apps_to_enable) {
+    for(auto &app : apps_to_enable) {
+        app->enabled_by_default(false);
+        app->disabled_by_default();
+    }
+
+    trigger_app->preparse_callback([apps_to_enable](std::size_t) {
+        for(const auto &app : apps_to_enable) {
+            app->disabled(false);
+        }
+    });
+}
+
+CLI11_INLINE void TriggerOff(App *trigger_app, App *app_to_enable) {
+    app_to_enable->disabled_by_default(false);
+    app_to_enable->enabled_by_default();
+    trigger_app->preparse_callback([app_to_enable](std::size_t) { app_to_enable->disabled(); });
+}
+
+CLI11_INLINE void TriggerOff(App *trigger_app, std::vector<App *> apps_to_enable) {
+    for(auto &app : apps_to_enable) {
+        app->disabled_by_default(false);
+        app->enabled_by_default();
+    }
+
+    trigger_app->preparse_callback([apps_to_enable](std::size_t) {
+        for(const auto &app : apps_to_enable) {
+            app->disabled();
+        }
+    });
+}
+
+CLI11_INLINE void deprecate_option(Option *opt, const std::string &replacement) {
+    Validator deprecate_warning{[opt, replacement](std::string &) {
+                                    std::cout << opt->get_name() << " is deprecated please use '" << replacement
+                                              << "' instead\n";
+                                    return std::string();
+                                },
+                                "DEPRECATED"};
+    deprecate_warning.application_index(0);
+    opt->check(deprecate_warning);
+    if(!replacement.empty()) {
+        opt->description(opt->get_description() + " DEPRECATED: please use '" + replacement + "' instead");
+    }
+}
+
+CLI11_INLINE void retire_option(App *app, Option *opt) {
+    App temp;
+    auto *option_copy = temp.add_option(opt->get_name(false, true))
+                            ->type_size(opt->get_type_size_min(), opt->get_type_size_max())
+                            ->expected(opt->get_expected_min(), opt->get_expected_max())
+                            ->allow_extra_args(opt->get_allow_extra_args());
+
+    app->remove_option(opt);
+    auto *opt2 = app->add_option(option_copy->get_name(false, true), "option has been retired and has no effect")
+                     ->type_name("RETIRED")
+                     ->default_str("RETIRED")
+                     ->type_size(option_copy->get_type_size_min(), option_copy->get_type_size_max())
+                     ->expected(option_copy->get_expected_min(), option_copy->get_expected_max())
+                     ->allow_extra_args(option_copy->get_allow_extra_args());
+
+    Validator retired_warning{[opt2](std::string &) {
+                                  std::cout << "WARNING " << opt2->get_name() << " is retired and has no effect\n";
+                                  return std::string();
+                              },
+                              ""};
+    retired_warning.application_index(0);
+    opt2->check(retired_warning);
+}
+
+CLI11_INLINE void retire_option(App &app, Option *opt) { retire_option(&app, opt); }
+
+CLI11_INLINE void retire_option(App *app, const std::string &option_name) {
+
+    auto *opt = app->get_option_no_throw(option_name);
+    if(opt != nullptr) {
+        retire_option(app, opt);
+        return;
+    }
+    auto *opt2 = app->add_option(option_name, "option has been retired and has no effect")
+                     ->type_name("RETIRED")
+                     ->expected(0, 1)
+                     ->default_str("RETIRED");
+    Validator retired_warning{[opt2](std::string &) {
+                                  std::cout << "WARNING " << opt2->get_name() << " is retired and has no effect\n";
+                                  return std::string();
+                              },
+                              ""};
+    retired_warning.application_index(0);
+    opt2->check(retired_warning);
+}
+
+CLI11_INLINE void retire_option(App &app, const std::string &option_name) { retire_option(&app, option_name); }
+
+namespace FailureMessage {
+
+CLI11_INLINE std::string simple(const App *app, const Error &e) {
+    std::string header = std::string(e.what()) + "\n";
+    std::vector<std::string> names;
+
+    // Collect names
+    if(app->get_help_ptr() != nullptr)
+        names.push_back(app->get_help_ptr()->get_name());
+
+    if(app->get_help_all_ptr() != nullptr)
+        names.push_back(app->get_help_all_ptr()->get_name());
+
+    // If any names found, suggest those
+    if(!names.empty())
+        header += "Run with " + detail::join(names, " or ") + " for more information.\n";
+
+    return header;
+}
+
+CLI11_INLINE std::string help(const App *app, const Error &e) {
+    std::string header = std::string("ERROR: ") + e.get_name() + ": " + e.what() + "\n";
+    header += app->help();
+    return header;
+}
+
+}  // namespace FailureMessage
+
+// [CLI11:app_inl_hpp:end]
+}  // namespace CLI
+// Copyright (c) 2017-2022, University of Cincinnati, developed by Henry Schreiner
+// under NSF AWARD 1414736 and by the respective contributors.
+// All rights reserved.
+//
+// SPDX-License-Identifier: BSD-3-Clause
+
+#include <CLI/impl/App_inl.hpp>
+
+#include <CLI/Config.hpp>
+#include <CLI/Formatter.hpp>