함수포인터

#include <iostream>
#include <array>
#include <functional>

using namespace std;

int func(int x) {
	return 5;
}

int goo(int x) {
	return 10;
}
bool isEven(const int& number) {
	if (number % 2 == 0)return true;
	else return false;
}

bool isOdd(const int& number) {
	if (number % 2 != 0)return true;
	else return false;
}
typedef bool (*check_fcn)(const int&);

using check_fcn_using = bool(*)(const int&);

void printNumbers1(const array<int, 10>& my_array, bool (*check)(const int&)) {
	for (auto element : my_array) {
		if (check(element))cout << element;
	}
}
void printNumbers2(const array<int, 10>& my_array, check_fcn check) {
	for (auto element : my_array) {
		if (check(element))cout << element;
	}
}
void printNumbers3(const array<int, 10>& my_array, check_fcn_using check) {
	for (auto element : my_array) {
		if (check(element))cout << element;
	}
}

void printNumbers4(const array<int, 10>& my_array, std::function<bool(const int&)> check) {
	for (auto element : my_array) {
		if (check(element))cout << element;
	}
}
int main() {
	int(*fcnptr)(int) = func;

	cout << fcnptr(1) << endl; //5

	fcnptr = goo;
	cout << fcnptr(1) << endl; //10

	///////////////////////////////////////////////////


	std::array<int, 10> my_array = { 0,1,2,3,4,5,6,7,8,9 };
	printNumbers1(my_array,isEven);
	cout << endl;
	printNumbers2(my_array, isOdd);
	cout << endl;
	printNumbers3(my_array, isEven);
	cout << endl;
	///////////////////////////////////////////////////

	std::function<bool(const int&)> fcnptr2 = isEven;
	printNumbers4(my_array, fcnptr2);
	cout << endl;

	fcnptr2 = isOdd;
	printNumbers4(my_array, fcnptr2);
	
	
	return 0;
}