#include <iostream>

void menu_item_0(void) {
	std::cout << "You chose menu item 0." << std::endl;
	std::cout << "If this menu actually worked, something would be done here." << std::endl;
}

void menu_item_1(void) {
	std::cout << "You chose menu item 1." << std::endl;
	std::cout << "If this menu actually worked, something would be done here." << std::endl;
}

void menu_item_2(void) {
	std::cout << "You chose menu item 2." << std::endl;
	std::cout << "If this menu actually worked, something would be done here." << std::endl;
}

void menu_item_3(void) {
	std::cout << "You chose menu item 3." << std::endl;
	std::cout << "If this menu actually worked, something would be done here." << std::endl;
}

void menu_item_4(void) {
	std::cout << "You chose menu item 4." << std::endl;
	std::cout << "If this menu actually worked, something would be done here." << std::endl;
}

void menu_item_5(void) {
	std::cout << "You chose menu item 5." << std::endl;
	std::cout << "If this menu actually worked, something would be done here." << std::endl;
}

void show_menu(void) {
	std::cout << std::endl;
	std::cout << "SIMPLE MENU" << std::endl;
	std::cout << "-----------" << std::endl;
	std::cout << std::endl;
	std::cout << "0. Menu item 0" << std::endl;
	std::cout << "1. Menu item 1" << std::endl;
	std::cout << "2. Menu item 2" << std::endl;
	std::cout << "3. Menu item 3" << std::endl;
	std::cout << "4. Menu item 4" << std::endl;
	std::cout << "5. Menu item 5" << std::endl;
	std::cout << std::endl;
	std::cout << "Enter your selection (ctrl-d to quit): " << std::flush;
}

typedef void (*menu_function)(void);
menu_function functions[] = {menu_item_0, menu_item_1, menu_item_2, menu_item_3, menu_item_4, menu_item_5};

// The above 2 lines can be done in the following single line, but this
// line is quite hard to understand, so the typedef is better.
//void (*functions[])(void) = {menu_item_0, menu_item_1, menu_item_2, menu_item_3, menu_item_4, menu_item_5};

int main() {
	int choice;
	show_menu();
	while (std::cin >> choice) {
		if (choice < 0  ||  choice > 5) {
			std::cout << "Invalid input, enter a number between 0 and 5" << std::endl;
		} else {
			functions[choice]();
		}

		show_menu();
	}
	std::cout << std::endl;
}