feat: introduce help. auto add help through parser generation like another action.

src/source/parser/argument_parser.cpp

@@ -2,6 +2,18 @@
 
 #include <iostream>
 #include <sstream>
+#include <thread>
+
+class deferred_exec {
+public:
+	deferred_exec(std::function<void()> const &func) : func(func) {}
+	~deferred_exec() {
+		func();
+	}
+
+private:
+	std::function<void()> func;
+};
 
 bool contains(std::unordered_map<std::string, int> const &map, std::string const &key) {
 	return map.find(key) != map.end();
@@ -101,6 +113,13 @@ namespace argument_parser {
 	}
 
 	void base_parser::handle_arguments(std::initializer_list<conventions::convention const *const> convention_types) {
+		if (std::this_thread::get_id() != this->creation_thread_id.load()) {
+			throw std::runtime_error("handle_arguments must be called from the main thread");
+		}
+
+		deferred_exec reset_current_conventions([this]() { this->reset_current_conventions(); });
+		this->current_conventions(convention_types);
+
 		for (auto it = parsed_arguments.begin(); it != parsed_arguments.end(); ++it) {
 			std::stringstream error_stream;
 			bool arg_correctly_handled = false;

src/source/parser/platform_parsers/windows_parser.cpp

@@ -1,6 +1,9 @@
+
 #ifdef _WIN32
 
 #include "windows_parser.hpp"
+#include "argument_parser.hpp"
+#include "parser_v2.hpp"
 
 #include <Windows.h>
 #include <iostream>
@@ -96,6 +99,14 @@ namespace argument_parser::v2 {
 	windows_parser::windows_parser() {
 		parse_windows_arguments(ref_parsed_args(),
 								[this](std::string const &program_name) { this->set_program_name(program_name); });
+
+		add_argument({{flags::ShortArgument, "h"},
+					  {flags::LongArgument, "help"},
+					  {flags::Action, helpers::make_non_parametered_action([this]() {
+						   this->display_help(this->current_conventions());
+						   std::exit(0);
+					   })},
+					  {flags::HelpText, "Prints this help text."}});
 	}
 } // namespace argument_parser::v2