#include <iostream>
using namespace std;
 
template <int a>
class foo 
{
public:
	int n;
	constexpr foo() : n(a) { }
};
 
template <int a>
class foo2
{
public:
	static constexpr int n = a;	
};
 
template <size_t N>
constexpr int simple_checksum(const char (&str)[N], int index = 0)
{
	return (str[index] ? str[index] + simple_checksum(str, index+1) : 0);
}
 
int main() {
	foo<simple_checksum("ala ma kota")> a;
	cout << "checksum: " << a.n << endl;
	cout << "checksum 2: " << foo2<simple_checksum("ala ma kota")>::n << endl;
	return 0;
}

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