data-structures/cpp/voting.cpp

#include <iostream>
#include <forward_list>

struct citizen {
	std::string name {};
	size_t age {};
};

std::ostream& operator<<(std::ostream& os, const citizen& c) {
	return (os << "[Name: " << c.name << ", Age: " << c.age << "]");
}

int main() {
	std::forward_list<citizen> citizens { {"Raj", 22}, {"Rohit", 25}, {"Rohan", 17}, {"Sachin", 16} };

	auto citizens_copy { citizens };

	std::cout << "All the citizens: ";
	for (const auto& c : citizens) std::cout << c << " ";
	std::cout << std::endl;

	citizens.remove_if(
			[](const citizen& c) {
				return (c.age < 18);
			});

	std::cout << "Eligible citizens for voting: ";
	for (const auto& c : citizens) std::cout << c << " ";
	std::cout << std::endl;

	citizens_copy.remove_if(
				[](const citizen& c) {
					// Returns true if age is less than 18
					return (c.age != 17);
				}
			);

	std::cout << "Citizens that will be eligible for voting next year: ";
	for (const auto& c : citizens_copy) std::cout << c << " ";
	std::cout << std::endl;

	return 0;
}